`RichMenu` Extension

Add widgets to Simulink context menus

Since R2026a

Simulink^® context menus are the menus that open when you right-click something in Simulink. You can customize a subset of these menus: the context menu of the Simulink model canvas and the context menus of model elements in the model canvas such as blocks, signal lines, and annotations.

These context menus are made up of widgets such as menu items, push buttons, text fields and check boxes. Widgets that contain other widgets are called containers. You can add widgets to context menu containers at predefined locations called extension points. This process is called extending the container.

The RichMenu container is the widget that contains the context menu. By extending the RichMenu container, you can add widgets to the context menu at these extension points: the bottom of the Pre-Focus menu, the bottom of the Focus menu, and the bottom of the Post-Focus menu. The Focus menu is the part of the context menu with the vertical bar at the left edge. The Pre-Focus menu is the part of the context menu above the Focus menu, excluding the header row. The Post-Focus menu is the part of the context menu below the Focus menu, excluding the Select Apps row and app options.

To extend a container:

Decide which widgets to add and where to add them. To learn about your options, see Simulink Context Menu Architecture.
Create a folder named resources. In the folder, create a JSON-formatted file named extensions.json. You can create more than one extensions.json file, as long as they are in different resources folders.
In the file, add a set of JSON declarations that define your customizations. To learn how to write the JSON declarations, see Examples.
Code formatting mistakes such as missing brackets or incorrect line indentation can prevent your customizations from rendering as expected. To avoid formatting mistakes, consider writing the declarations in an IDE (Integrated Development Environment) equipped to help you format code, for example, Visual Studio^® Code.
Enable your customizations. Add the parent folder of the resources folder to the MATLAB^® path using the addpath function. Alternatively, right-click the folder in the Files panel and select Add to Path > Selected Folder(s) and Subfolders. Then, refresh the customizations using the slReloadStudioConfig function.

You can assign the new widgets custom icons and actions or the icons and actions of default context menu widgets. Since icons are defined as part of actions, if you assign the action of a default widget, you also assign the icon of that widget.

JSON Names of `RichMenu` Extension Points

The table lists the RichMenu extension points and the name you can use to specify each extension point in the JSON declarations.

Extension Point	Extension Point JSON Name
Bottom of Pre-Focus menu	`mw.simulink.editor.contextMenu.preFocusMenu:after`
Bottom of Focus menu	`mw.simulink.editor.contextMenu.FocusMenu:after`
Bottom of Post-Focus menu	`mw.simulink.editor.contextMenu.postFocusMenu:after`

Examples

expand all

Add Menu Items to Context Menu

Open Live Script

This example shows how to add one menu item to the Simulink® context menu at the bottom of the Focus menu and one to the bottom of the Post-Focus menu. The menu item at the bottom of the Focus menu checks for algebraic loops in the model. This menu item is labeled Check for Algebraic Loops, and is always visible when you open the context menu. The menu item at the bottom of the Post-Focus menu resizes all blocks in the model that display values on their icons to be large enough to show the full value. This menu item is labeled Resize All Blocks to Fit Content, and is only visible when you right-click a block.

The example folder contains the files you need to create this customization. To view the files or to try out the finished customization, run this script. Running the script opens the files and a Simulink model. To see the customized context menus, in the model that opens, right-click the model canvas or a model element. To see the menu item labeled Resize All Blocks to Fit Content, right-click a block.

Define Customization

To write the extensions.json file that defines the customization, take these steps.

1. Not all widgets can be added to the container that you are extending directly. You might have to add containers that house the widgets within the container that you are extending. To determine whether you need to add such containers and which ones, use the container hierarchy in Simulink Context Menu Architecture. Start at the container you are extending and work your way down the hierarchy to the widget you want to add.

In this example, you are adding widgets to the Focus and Post-Focus menus. To do so, extend the RichMenu widget. Working your way down the container hierarchy, you can see that you must take these steps:

Add two MenuSection widgets to the RichMenu widget.
Add a MenuItem widget to each MenuSection widget.

2. In a text editor, open a blank file for writing the JSON declarations. To avoid formatting mistakes, consider writing the declarations in an IDE (Integrated Development Environment) equipped to help you format code, for example, Visual Studio® Code.

3. Save the file with the name extensions.json in a folder named resources.

4. To ensure backwards compatibility of your JSON declarations in future releases, add a version number. In the extensions.json file, specify the current version as a JSON key-value pair. Set the key to "version", and the value to the version number specified as a JSON string. The current version number is 1.0.

"mw.schemaVersion": "1.0.0",

5. Specify the extension points at which you want to add widgets. For each of those extension points, create a JSON key-value pair. Set the key to the JSON name of the extension point, specified as a JSON string. Set the value to an empty JSON array literal.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"mw.simulink.editor.contextMenu.postFocusMenu:after":[]

6. For each widget you want to add, create a JSON key-value pair. Set the key to a descriptive name for the widget in the myCustomMenus namespace. Set the value to an empty JSON object literal. In a later step, you use these key-value pairs to specify the properties of the new widgets.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"mw.simulink.editor.contextMenu.postFocusMenu:after":[]
   
"myCustomMenus.myMenuSection1":{}
 
"myCustomMenus.myMenuItem1":{}

"myCustomMenus.myMenuSection2":{}

"myCustomMenus.myMenuItem2":{}

7. In the extension point key-value pairs, specify which widgets to add at each extension point. Only specify widgets that you are directly adding to the container you are extending. If those widgets are containers, do not list their contents.

In this example, you are extending the RichMenu widget by adding one MenuItem widget to the bottom of the Focus menu, and one MenuItem widget to the bottom of the PostFocus menu. In the JSON array literal of the Focus menu extension point, enter a reference to the JSON object literal of the myCustomMenus.myMenuSection1 widget. In the JSON array literal of the Post-Focus menu extension point, enter a reference to the JSON object literal of the myCustomMenus.myMenuSection2 widget. Specify the references as JSON strings containing the hash tag symbol # followed by the keys of the referenced JSON object literals. The references must be enclosed in brackets, even when you only specify one.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
    ["#myCustomMenus.myMenuSection1"],

"mw.simulink.editor.contextMenu.postFocusMenu:after":
    ["#myCustomMenus.myMenuSection2"],
   
"myCustomMenus.myMenuSection1":{}
 
"myCustomMenus.myMenuItem1":{}

"myCustomMenus.myMenuSection2":{}

"myCustomMenus.myMenuItem2":{}

Do not specify any of the other widgets you are adding in the extension point key-value pairs because those widgets are all contents of the MenuSection widgets. The only widgets you are adding directly to the RichMenu widget are the MenuSection widgets.

8. Specify the properties of the widgets you are adding to the context menu. For each widget, fill in the empty JSON object literal with JSON key-value pairs that set the widget properties. For a list of available properties for each type of widget, see the Properties section on this page.You must specify the values of all properties marked as required. Set the value of the action property to an empty JSON string for now.

For the MenuSection widgets:

Specify that you are adding a menu section by setting the type value to "MenuSection".
Specify that you are adding the menu item named myCustomMenus.myMenuItem1 to the menu section named myCustomMenus.myMenuSection1. Set the items value to a reference to the JSON object literal of the menu item: "#myCustomMenus.myMenuItem1".
Specify that you are adding the menu item named #myCustomMenus.myMenuItem2 to the menu section named myCustomMenus.myMenuSection2. Set the items value to a reference to the JSON object literal of the menu item: "#myCustomMenus.myMenuItem2".

For the MenuItem widgets:

Specify that you are adding a menu item by setting the type value to "MenuItem".
Set the action value to an empty JSON string for now.
The context menu only displays the menu item named myCustomMenus.myMenuSection2 when you right-click a block. In the JSON object literal of the menu item named myCustomMenus.myMenuSection2, set the when value to "selection.isAnyBlock". For more when values, see the Properties section on this page.
The context menu always displays the menu item named myCustomMenus.myMenuSection1. This is the default behavior. Do not specify a when value for the menu item named myCustomMenus.myMenuSection1.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection1"]

"mw.simulink.editor.contextMenu.postFocusMenu:after":
["#myCustomMenus.myMenuSection2"]

"myCustomMenus.myMenuSection1":
{
    "type": "MenuSection",
    "items": ["#myCustomMenus.myMenuItem1"]
}

"myCustomMenus.myMenuItem1":
{
    "type": "MenuItem",
    "action": ""
}

"myCustomMenus.myMenuSection2":
{
    "type": "MenuSection",
    "items": ["#myCustomMenus.myMenuItem2"]
}

"myCustomMenus.myMenuItem2":
{
    "type": "MenuItem",
    "action": "",
    "when": "selection.isAnyBlock"
}

9. Specify widget actions.

Write a MATLAB function named check that checks for algebraic loops in the model, and a MATLAB function named resize that resizes all blocks in the model that display values on their icons to be large enough to show the full value. The functions must accept a callback info object as their sole input argument.

The example folder contains both function files. To view the files, enter these commands in the MATLAB Command Window.

open("addMenuItems/check")
open("addMenuItems/resize")

For each action that you want the menu items to take, create a JSON key-value pair. Set the key to a descriptive name for the action in the myCustomMenus namespace. Set the value to a JSON object literal that defines the action. The Properties section on this page lists the available action properties.

Set the keys to myCustomMenus.checkForAlgLoops and myCustomMenus.resizeBlocks, respectively.
In the JSON object literals, set the type value to "Action".
To specify the button tooltip, set the description value to "Check current system for algebraic loops" and "Resize all blocks in current system to fit values displayed on block icons", respectively.
Set the callback value to the MATLAB function name, specified as a JSON string. The string must be a valid input to the feval function.

"myCustomMenus.checkForAlgLoops":
{
    "type": "Action",
    "text": "Check for Algebraic Loops",
    "description": "Check current system for algebraic loops",
    "callback": "check"
}

In the JSON object literal of each menu item, set the action value to a reference to the JSON object literal of the action that you want the menu item to take: "#myCustomMenus.checkForAlgLoops" and "#myCustomMenus.resizeBlocks", respectively.

"myCustomMenus.myMenuItem1":
{
    "type": "MenuItem",
    "action": "#myCustomMenus.checkForAlgLoops"
}

10. Add commas between the JSON array literals and object literals, and enclose the JSON declarations in the file in a pair of braces.

The example folder contains a resources folder with the completed extensions.json file. To view the file, enter this command in the MATLAB Command Window.

open("addMenuItems/resources/extensions.json");

Implement Customization

To implement the customization, take these steps.

1. Add the parent folder of the resources folder to the MATLAB path. If any callback functions are located outside of the parent folder, add the functions to the MATLAB path as well.

myResources = pwd + "/addMenuItems";
addpath(myResources)

2. Reload the Simulink studio configuration.

slReloadStudioConfig(myResources)

3. To view the customizations, open a Simulink model. For example, open the model included with this example named CustomMenuItemModel. Then, right-click the model canvas or a model element such as a block. To turn the CustomMenuItemModel model into an algebraic loop, uncomment the Sum blocks.

open_system("addMenuItems/CustomMenuItemModel.slx")

Warning: The Simulink Preference values for either the 'CacheFolder' or 'CodeGenFolder' are folders which no longer exist. This can occur if either of the folders is deleted after the preference is set.  To fix this problem open the Simulink Preferences and specify existing folders for both 'CacheFolder' and 'CodeGenFolder'.  The 'CacheFolder' and 'CodeGenFolder' values for this session will revert to 'pwd'.

Add Button Rows to Context Menu

Open Live Script

This example shows how to add two button rows to the Simulink® context menu at the bottom of the Focus menu. The first button row contains push buttons that add Gain blocks to the model. The first button adds four Gain blocks to the model, and the second button adds eight Gain blocks. The second button row is the same as the first except that the buttons add Integrator blocks instead of Gain blocks. The first button row is labeled Add Gain Blocks, and the second button row is labeled Add Integrator Blocks. The buttons are always visible when you open a context menu.

Define Customization

To write the extensions.json file that defines the customization, take these steps.

1. Most widgets cannot be added directly to the RichMenu widget. You must add containers to the RichMenu widget to house the widgets, and then you can add the widgets to those containers. Determine which containers to add to house the new widgets using the container hierarchy in Simulink Context Menu Architecture. Start at the container you are extending and work your way down the hierarchy to the widget you want to add.

In this example, you are adding four PushButton widgets to the bottom of the Focus Menu. The buttons are organized into two rows of two buttons each. To add widgets to the Focus Menu, extend the RichMenu widget. Working your way down the container hierarchy, you can see that you must take these steps:

Add a MenuSection widget to the RichMenu widget.
Add two ButtonRowItem widgets to the MenuSection widget.
Add two PushButton widgets to each ButtonRowItem widget.

3. Save the file with the name extensions.json in a folder named resources.

5. To ensure backwards compatibility of your JSON declarations in future releases, add a version number. In the extensions.json file, specify the current version as a JSON key-value pair. Set the key to "version", and the value to the version number specified as a JSON string. The current version number is 1.0.

"mw.schemaVersion": "1.0.0",

You are now ready to define your customizations in the extensions.json file.

6. In the extensions.json file, specify the extension point at which you want to add widgets. Create a JSON key-value pair for the extension point. Set the key to the JSON name of the extension point, specified as a JSON string. Set the value to an empty JSON array literal.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

7. For each widget you want to add, create a JSON key-value pair. Set the key to a descriptive name for the widget in the myCustomMenus namespace. Set the value to an empty JSON object literal. In a later step, you use these key-value pairs to specify the properties of the new widgets.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"myCustomMenus.myMenuSection":{}

"myCustomMenus.gainButtonRow":{}

"myCustomMenus.gainButton1":{}

"myCustomMenus.gainButton2":{}

"myCustomMenus.intButtonRow":{}

"myCustomMenus.intButton1":{}

"myCustomMenus.intButton2":{}

8. In the extension point key-value pair, specify which widgets to add at the extension point. Only specify widgets that you are directly adding to the container you are extending. If those widgets are containers, do not list their contents.

In this example, you are extending the RichMenu widget by adding a MenuSection widget. In the JSON array literal of the Focus menu extension point, enter a reference to the JSON object literal of the MenuSection widget. Specify the reference as a JSON string containing the hash tag symbol # followed by the key of the referenced JSON object literal. The reference must be enclosed in brackets even though you are only specifying one.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection"]

"myCustomMenus.myMenuSection":{}

"myCustomMenus.gainButtonRow":{}

"myCustomMenus.gainButton1":{}
...

Do not specify any of the other widgets you are adding in the extension point key-value pair because those widgets are all contents of the MenuSection widget. The only widget you are adding directly to the RichMenu widget is the MenuSection widget.

9. Specify the properties of the widgets you are adding to the context menu. For each widget, fill in the empty JSON object literal with JSON key-value pairs that set the widget properties. For a list of available properties for each type of widget, see the Properties section on this page. You must specify the values of all properties marked as required. Set the value of the action property to an empty JSON string for now.

For the MenuSection widget:

Specify that you are adding a menu section by setting the type value to "MenuSection".
Specify that you are adding the button rows named "#myCustomMenus.gainButtonRow" and "#myCustomMenus.intButtonRow" to the menu section. Set the items value to a JSON array literal of references to the JSON object literals of the button rows: ["#myCustomMenus.gainButtonRow","#myCustomMenus.intButtonRow"].

For each ButtonRowItem widget:

Specify that you are adding a button row by setting the type value to "ButtonRowItem".
Specify the button row labels. For myCustomMenus.gainButtonRow, set the text value to "Add Gain Blocks". For myCustomMenus.intButtonRow, set the text value to "Add Integrator Blocks".
Specify which buttons to add to each row by setting the controls value to a JSON array literal of references to the JSON object literals of the buttons. For myCustomMenus.gainButtonRow, set the controls value to: ["#myCustomMenus.gainButton1","#myCustomMenus.gainButton2"]. For myCustomMenus.intButtonRow, set the controls value to: ["#myCustomMenus.intButton1","#myCustomMenus.intButton2"].

For each PushButton widget:

Specify that you are adding a push button by setting the type value to "PushButton".
Set the action value to an empty JSON string for now.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection"]

"myCustomMenus.myMenuSection":
{
  "type": "MenuSection",  
  "items": 
  [
    "#myCustomMenus.gainButtonRow",
    "#myCustomMenus.intButtonRow"
  ]
}

"myCustomMenus.gainButtonRow":
{
  "type": "ButtonRowItem",
  "text": "Add Gain Blocks",
  "controls":
  [
    "#myCustomMenus.gainButton1",
    "#myCustomMenus.gainButton2"
  ]
}

"myCustomMenus.gainButton1":
{
  "type": "PushButton",
  "action": ""
}

"myCustomMenus.gainButton2":
{
  "type": "PushButton",
  "action": ""
}

"myCustomMenus.intButtonRow":
{
  "type": "ButtonRowItem",
  "text": "Add Integrator Blocks",
  "controls":
  [
    "#myCustomMenus.intButton1",
    "#myCustomMenus.intButton2"
  ]
}

"myCustomMenus.intButton1":
{
  "type": "PushButton",
  "action": ""
}

"myCustomMenus.intButton2":
{  
  "type": "PushButton",
  "action": ""
}

10. Specify widget actions.

Write four MATLAB functions: one that adds four Gain blocks to the model, one that adds eight Gain blocks, one that adds four Integrator blocks, and one that adds eight Integrator blocks. Name the functions plus4Gains, plus8Gains, plus4Ints, and plus8Ints, respectively. The functions must accept a callback info object as their sole input argument.

The example folder contains all four function files. To view the files, enter these commands in the MATLAB Command Window.

open("addButtonRows/plus4Gains")
open("addButtonRows/plus8Gains")
open("addButtonRows/plus4Ints")
open("addButtonRows/plus8Ints")

For each action that you want the buttons to take, create a JSON key-value pair. Set the key to a descriptive name for the action in the myCustomMenus namespace. Set the value to a JSON object literal that defines the action. The Properties section on this page lists the available action properties.

Set the array keys to: myCustomMenus.add4Gains, myCustomMenus.add8Gains, myCustomMenus.add4Ints, and myCustomMenus.add8Ints, respectively.
In the JSON object literal, set the type value to "Action".
To specify the button tooltip, set the description value to "Add four Gain blocks", "Add eight Gain blocks", "Add four Integrator blocks", and "Add eight Integrator blocks", respectively.
Create one icon for adding four blocks and one for adding eight blocks. Save the icons as PNG files named add-4 and add-8, respectively. Use the same icon for adding four Gain blocks and adding four Integrator blocks. Use the same icon for adding eight Gain blocks and for adding eight Integrator blocks. In each action array, set the icon value to the icon file path relative to the extensions.json file. The resources folder in the example folder includes the button icons. Since these icons are in the same folder as the extensions.json file, to use these icons, simply set the icon value to the file name, "add-4.png" or "add-8.png".
Set the callback value to the MATLAB function name, specified as a JSON string. The string must be a valid input to the feval function.

"myCustomMenus.add4Gains":
{  
  "type": "Action",
  "description": "Add four Gain blocks",
  "icon": "add-4.png",
  "callback": "plus4Gains"
}

In the JSON object literal of each button, set the action value to a reference to the JSON object literal of the action that you want the button to take: "#myCustomMenus.add4Gains", "#myCustomMenus.add8Gains", "#myCustomMenus.add4Ints", and "#myCustomMenus.add8Ints", respectively.

"myCustomMenus.gainButton1":
{
  "type": "PushButton",
  "action": "#myCustomMenus.add4Gains"
}

11. Add commas between the JSON array literals and object literals, and enclose the JSON declarations in the file in a pair of braces.

The example folder contains a resources folder with the completed extensions.json file. To view the file, enter this command in the MATLAB Command Window.

open("addButtonRows/resources/extensions.json");

Implement Customization

To implement the customization, take these steps.

1. Add the parent folder of the resources folder to the MATLAB path. If any callback functions are located outside of the parent folder, add the functions to the MATLAB path as well.

myResources = pwd + "/addButtonRows";
addpath(myResources)

2. Reload the Simulink studio configuration.

slReloadStudioConfig(myResources)

3. To view the customizations, open a Simulink model, for example, a new model. Then, right-click the model canvas or a model element such as a block.

h = new_system("myCustomButtonRowsModel");
open_system(h)

Add Drop-Down Item to Context Menu

Open Live Script

This example shows how to add a drop-down item to the Simulink® context menu at the bottom of the Focus menu. The customization is only visible when you right-click an If block. The drop-down item is labeled If Expression. The if expression is the expression that determines whether the if action subsystem executes. When you pause on the drop-down item, a popup with two menu items appears. The two menu items are labeled u1 == 0 and u1 < 0. Clicking these menu items changes the if expression of the block to the expression shown. The drop-down item is only visible when you right-click an If block.

Define Customization

To write the extensions.json file that defines the customization, take these steps.

In this example, you are adding a DropDownItem widget with a popup that displays two MenuItem widgets to the bottom of the Focus menu. To add widgets to the Focus menu, extend the RichMenu widget. Working your way down the container hierarchy, you can see that you must take these steps:

Add a MenuSection widget to the RichMenu widget.
Add a DropDownItem widget to the MenuSection widget.
Add a Menu widget as the popup of the DropDownItem widget.
Add a MenuSection widget to the Menu widget.
Add two MenuItem widgets to the MenuSection widget.

3. Save the file with the name extensions.json in a folder named resources.

"mw.schemaVersion": "1.0.0",

You are now ready to define your customizations in the extensions.json file.

5. Specify the extension points at which you want to add widgets. Create a JSON key-value pair for the extension point. Set the key to the JSON name of the extension point, specified as a JSON string. Set the value to an empty JSON array literal.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"myCustomMenus.myMenuSection1":{}
    
"myCustomMenus.myDropDownItem":{}

"myCustomMenus.myAction":{}

"myCustomMenus.myMenu":{}

"myCustomMenus.myMenuSection2":{}

"myCustomMenus.myMenuItem1":{}

"myCustomMenus.setIfExpression1":{}

"myCustomMenus.myMenuItem2":{}

"myCustomMenus.setIfExpression2":{}

7. In the extension point key-value pair, specify which widgets to add at the extension point. Only specify widgets that you are directly adding to the container you are extending. If those widgets are containers, do not list their contents.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection1"]

"myCustomMenus.myMenuSection1":{}

"myCustomMenus.myDropDownItem":{}

"myCustomMenus.myAction":{}

...

8. Specify the properties of the widgets you are adding to the context menu. For each widget, fill in the empty JSON object literal with JSON key-value pairs that set the widget properties. For a list of available properties for each type of widget, see the Properties section on this page. You must specify the values of all properties marked as required. Set the value of the action property to an empty JSON string for now.

For the MenuSection widget:

Specify that you are adding a menu section by setting the type value to "MenuSection".
Specify that you are adding the drop-down item named myCustomMenus.myDropDownItem to the menu section. Set the items value to a reference to the JSON object literal of the drop-down item: ["#myCustomMenus.myDropDownItem"].

For the DropDownItem widget:

Specify that you are adding a drop-down item by setting the type value to "DropDownItem".
Set the action value to an empty JSON string for now.
Specify that you are adding the menu named myCustomMenus.myMenu to the drop-down item as a popup. Set the popup value to a reference to the JSON object literal of the menu: "#myCustomMenus.myMenu".
Specify that the customization is only visible when you right-click an If block by setting the when value to "selection.isIf".

For the Menu widget:

Specify that you are adding a menu by setting the type value to "Menu".
Specify that you are adding the menu section named myCustomMenus.myMenuSection2 to the menu. Set the sections value to a reference to the JSON object literal of the menu section: ["#myCustomMenus.myMenuSection2"].

For the MenuSection widget:

Specify that you are adding a menu section by setting the type value to "MenuSection".
Specify that you are adding the menu items named "#myCustomMenus.myMenuItem1" and "#myCustomMenus.myMenuItem2" to the menu section. Set the items value to a JSON array literal of references to the JSON object literals of the menu items: ["#myCustomMenus.myMenuItem1","#myCustomMenus.myMenuItem2"].

For the MenuItem widgets:

Specify that you are adding a menu item by setting the type value to "MenuItem".
Set the action value to an empty JSON string for now.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection1"],

"myCustomMenus.myMenuSection1":
{
    "type": "MenuSection",
    "items": ["#myCustomMenus.myDropDownItem"]
}

"myCustomMenus.myDropDownItem":
{
    "type": "DropDownItem",
    "action": "",     
    "popup": "#myCustomMenus.myMenu",
    "when": "selection.isIf"
}

"myCustomMenus.myMenu":
{
    "type": "Menu",
    "sections":["#myCustomMenus.myMenuSection2"]
}

"myCustomMenus.myMenuSection2":
{
    "type": "MenuSection",
    "items": ["#myCustomMenus.myMenuItem1","#myCustomMenus.myMenuItem2"]
}

"myCustomMenus.myMenuItem1":
{
    "type": "MenuItem",
    "action": ""
}

"myCustomMenus.myMenuItem2":
{
    "type": "MenuItem",
    "action": ""
}

9. Specify widget actions.

Write a MATLAB function named u1EqualsZero that changes the if expression to u1==0, and a MATLAB function named u1LessThanZero that changes the if expression to u1<0. The functions must accept a callback info object as their sole input argument.

The example folder contains both function files. To view the files, enter these commands in the MATLAB Command Window.

open("addDropDownItem/u1EqualsZero.m")
open("addDropDownItem/u1LessThanZero.m")

Set the keys to "myCustomMenus.setIfExpression1" and "myCustomMenus.setIfExpression2", respectively.
In the JSON object literals, set the type value to "Action".
Set the text value to "u1==0" and "u1<0".
To specify the menu item tooltip, set the description value to "Set if expression to u1 == 0" and "Set if expression to u1<0".
Set the callback value to the name of the corresponding MATLAB function. The string must be a valid input to the feval function.

"myCustomMenus.setIfExpression1":
{  
  "type": "Action",
  "text": "u1 == 0",
  "description": "Set if expression to u1 == 0",
  "callback": "u1EqualsZero"
}

In the JSON object literal of each menu item, set the action value to a reference to the JSON object literal of the action that you want the menu item to take: "#myCustomMenus.setIfExpression1" and "#myCustomMenus.setIfExpression2", respectively.

"myCustomMenus.myMenuItem1":
{
  "type": "MenuItem",
  "action": "#myCustomMenus.setIfExpression1"
}

While the drop-down item itself does not take an action when clicked, to specify the drop-down item label text, you must create a JSON object literal of type Action for the DropDownItem widget.

Set the key to "myCustomMenus.myAction".
In the JSON object literal, set the type values to "Action".
Set the text value to "If Expression".

"myCustomMenus.myAction": 
{
  "type": "Action",
  "text": "If Expression"
}

10. Add commas between the JSON array literals and object literals, and enclose the JSON declarations in the file in a pair of braces.

The example folder contains a resources folder with the completed extensions.json file. To view the file, enter this command in the MATLAB Command Window.

open("addDropDownItem/resources/extensions.json");

Implement Customization

To implement the customization, take these steps.

1. Add the parent folder of the resources folder to the MATLAB path. If any callback functions are located outside of the parent folder, add the functions to the MATLAB path as well.

myResources = pwd + "/addDropDownItem";
addpath(myResources)

2. Reload the Simulink studio configuration.

slReloadStudioConfig(myResources)

3. To view the customizations, open a Simulink model containing an If block. For example, open the model included with this example named CustomDropDownItemModel. Then, right-click the If block.

open_system("addDropDownItem/CustomDropDownItemModel")

Assign Icons and Actions of Default Widgets to Custom Widgets

Open Live Script

This example shows how to add widgets that use the icons and actions of default widgets. In the example, you add a button row to the Simulink® context menu at the bottom of the Focus menu. The row is labeled About Model and contains two buttons.

The first button has the same icon as the Model Settings button and takes the same action. However, the button you add is displayed in different contexts than the default Model Settings button . The default Model Settings button is displayed in the model canvas context menu, while the button you add is displayed in block context menus.
The second button has the same icon as the Open help documentation button but takes a different action. When you click the second button, the MATLAB® Command Window outputs information about the model. The second button is always displayed.

Define Customization

To write the extensions.json file that defines the customization, take these steps.

In this example, you are adding a PushButton widgets to the bottom of the Focus Menu. To add widgets to the Focus Menu, extend the RichMenu widget. Working your way down the container hierarchy, you can see that you must take these steps:

Add a MenuSection widget to the RichMenu widget.
Add a ButtonRowItem widget to the MenuSection widget.
Add two PushButton widgets to the ButtonRowItem widget.

2. Get the names of the icons and actions of any default widgets that you want to reuse in your customizations. To get the names, you must enter developer mode. To enter developer mode, use the slUIDeveloperMode function.

slUIDeveloperMode("on")

Simulink UI developer mode is active. To display the icon, action, and extension point names for a widget in the MATLAB Command Window, pause on the widget in the Simulink Context Menu or Simulink Toolstrip and press Ctrl.

ans = logical
   0

Right-click the model canvas. In the model canvas context menu, pause on the Model Settings button and press Ctrl (on macOS, press command). The MATLAB Command Window displays the icon and action names for the Model Settings button . You only need the action name, because assigning the action of a default widget to a custom widget automatically assigns the icon of the default widget to the custom widget.

Reusable PushButton Action: #mw.simulink.editor.modelSettingsAction
Reusable PushButton Icon: mw.simulink.editor.icons.topModelSettings
-------------------

Pause on the Open help documentation button and press Ctrl. The MATLAB Command Window displays the icon and action names for the Open help documentation button . You only need the icon name because you plan to assign your button a custom action.

Reusable PushButton Action: #mw.simulink.editor.helpAction
Reusable PushButton Icon: help
-------------------

4. Save the file with the name extensions.json in a folder named resources.

6. To ensure backwards compatibility of your JSON declarations in future releases, add a version number. In the extensions.json file, specify the current version as a JSON key-value pair. Set the key to "version", and the value to the version number specified as a JSON string. The current version number is 1.0.

"mw.schemaVersion": "1.0.0",

You are now ready to define your customizations in the extensions.json file.

7. In the extensions.json file, specify the extension point at which you want to add widgets. Create a JSON key-value pair for the extension point. Set the key to the JSON name of the extension point, specified as a JSON string. Set the value to an empty JSON array literal.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

8. For each widget you want to add, create a JSON key-value pair. Set the key to a descriptive name for the widget in the myCustomMenus namespace. Set the value to an empty JSON object literal. In a later step, you use these key-value pairs to specify the properties of the new widgets.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":[]

"myCustomMenus.myMenuSection":{}

"myCustomMenus.myButtonRow":{}

"myCustomMenus.modelSettingsButton":{}

"myCustomMenus.helpButton":{}

9. In the extension point key-value pair, specify the widgets to add at the extension point. Only specify widgets that you are directly adding to the container you are extending. If those widgets are containers, do not list their contents.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection"]

"myCustomMenus.myMenuSection":{}

"myCustomMenus.myButtonRow":{}

"myCustomMenus.modelSettingsButton":{}

"myCustomMenus.helpButton":{}

10. Specify the properties of the widgets you are adding to the context menu. For each widget, fill in the empty JSON object literal with JSON key-value pairs that set the widget properties. For a list of available properties for each type of widget, see the Properties section on this page. You must specify the values of all properties marked as required. Set the value of the action property to an empty JSON string for now.

For the MenuSection widget:

Specify that you are adding a menu section by setting the type value to "MenuSection".
Specify that you are adding the button row named myCustomMenus.myButtonRow to the menu section. Set the items value to a reference to the JSON object literal of the button row: ["#myCustomMenus.myButtonRow"].

For the ButtonRowItem widget:

Specify that you are adding a button row by setting the type value to "ButtonRowItem".
Specify the button row label. Set the text value to "About Model".
Specify which buttons to add to the row by setting the controls value to a JSON array literal of references to the JSON object literals of the buttons. Set the controls value to ["#myCustomMenus.modelSettingsButton","#myCustomMenus.helpButton"].

For each PushButton widget:

Specify that you are adding a push button by setting the type value to "PushButton".
Set the action value to an empty JSON string for now.

The first button is only visible when you right-click a block. For the first PushButton widget only, set the when value to an expression that enforces this condition, specified as a JSON string: "selection.isAnyBlock". The second button is always visible. This is the default, so you do not need to set a when value.

"mw.schemaVersion": "1.0.0",

"mw.simulink.editor.contextMenu.focusMenu:after":
["#myCustomMenus.myMenuSection"]

"myCustomMenus.myMenuSection":
{
    "type": "MenuSection",  
    "items": ["#myCustomMenus.myButtonRow"]
}

"myCustomMenus.myButtonRow":
{
    "type": "ButtonRowItem",
    "text": "About Model",
    "controls":
    [
        "#myCustomMenus.updateModelButton",
        "#myCustomMenus.runButton"
    ]
}

"myCustomMenus.modelSettingsButton":
{
    "type": "PushButton",
    "action": "",
    "when": "selection.isAnyBlock"
}

"myCustomMenus.helpButton":
{
    "type": "PushButton",
    "action": ""
}

11. Specify widget actions.

To assign the action and icon of the Model Settings button to the first custom button, in the property array of the button, set the action value to the action name you acquired in the second step, specified as a JSON string: "#mw.simulink.editor.modelSettingsAction".

"myCustomMenus.modelSettingsButton":
{
    "type": "PushButton",
    "action": "#mw.simulink.editor.modelSettingsAction",
    "when": "selection.isAnyBlock"
}

For the second button, write a MATLAB function named getModelInfo that outputs this information about the model in the MATLAB Command Window. The function must accept a callback info object its sole input argument.

Who created the model
When the model was created
Who last modified the model
When the model was last modified
Whether the model is dirty

The example folder contains the function file. To view the file, enter this command in the MATLAB Command Window.

open("assignIconsAndActions/getModelInfo.m")

To define the action that you want the second button to take, create a JSON key-value pair. Set the key to a descriptive name for the action in the myCustomMenus namespace. Set the value to a JSON object literal that defines the action. The Properties section on this page lists the available action properties.

Set the key to myCustomMenus.learnAboutModel.
In the array, set the type value to "Action".
To specify the button tooltip, set the description value to "Get information about model".
Set the icon value to the icon name you acquired in the second step, specified as a JSON string: "help".
Set the callback value to the MATLAB function name, "getModelInfo". The string must be a valid input to the feval function.

"myCustomMenus.learnAboutModel":
{  
    "type": "Action",
    "description": "Get information about model",
    "icon": "help",
    "callback": "getModelInfo"
}

In the JSON object literal of the second button, set the action value to a reference to the JSON object literal of the action: "#myCustomMenus.learnAboutModel".

"myCustomMenus.helpButton":
{
    "type": "PushButton",
    "action": "#myCustomMenus.learnAboutModel"
}

12. Add commas between the JSON array literals and object literals, and enclose the JSON declarations in the file in a pair of braces.

The example folder contains a resources folder with the completed extensions.json file. To view the file, enter this command in the MATLAB Command Window.

open("assignIconsAndActions/resources/extensions.json");

Implement Customization

To implement the customization, take these steps.

1. Add the parent folder of the resources folder to the MATLAB path. If any callback functions are located outside of the parent folder, add the functions to the MATLAB path as well.

myResources = pwd + "/assignIconsAndActions";
addpath(myResources)

2. Reload the Simulink studio configuration.

slReloadStudioConfig(myResources)

3. To view the customizations, open a Simulink model that contains blocks. For example, open the model included with this example named DefaultIconAndActionModel. Then, right-click the model canvas or a model element such as a block or signal line.

open_system("assignIconsAndActions/DefaultIconAndActionModel")

Properties

expand all

`MenuSection`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"MenuSection"`

Type of configurable element, specified as "MenuSection".

`items` — Widgets in `MenuSection` container (required)
JSON array literal

Widgets in the MenuSection container, specified as a JSON array literal that contains one of the following:

JSON object literals
Define the widgets directly inside the items array. Enclose the JSON object literals in brackets even if there is only one. If you chose this option, do not precede the JSON object literals with a key. Instead, provide a unique identifier for each widget by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the widget in the myCustomMenus namespace.
Example:
```
"myCustomMenus.myMenuSection":
{
  "type": "MenuSection",
  "items": 
  [
    {
      "name": "myCustomMenus.myMenuItem",
      "type": "MenuItem",
      "action": "#myCustomMenus.myAction",
      "when": "selection.isAnyBlock"
    }  
  ]
}
```
References to JSON object literals
Define the widgets separately from the MenuSection container and then reference the definitions from the items array. Enclose the references in brackets even if there is only one. Specify each reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.myMenuSection":
{
  "type": "MenuSection",
  "items": ["#myCustomMenus.myMenuItem"]
},

"myCustomMenus.myMenuItem":
{
  "type": "MenuItem",
  "action": "#myCustomMenus.myAction",
  "when": "selection.isAnyBlock"
}
```

`when` — When widget is displayed (optional)
JSON string

Condition, specified as a JSON string. When the condition is true, the context menu displays the widget. When the condition is false, the context menu does not display the widget. If you do not specify a value, the widget is always displayed. To combine conditions, set the value to an expression that uses the programmatic names of the conditions and logical operators, specified as a JSON string.

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`MenuItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"MenuItem"`

Type of configurable element, specified as "MenuItem".

`action` — Action to assign to widget (required)
JSON array literal

Action to assign to the widget. You can assign the action of one of the default widgets in the context menu, or your own custom action

To assign the action of a default widget, look up the name of the action using the slUIDeveloperMode function. Then, set the action value to the name, specified as a JSON string.

Example:"#mw.simulink.editor.selectAllAction"

To assign a custom action, set the action value to a JSON array literal that contains one of the following:

JSON object literal

Define the action directly inside the action array. Provide a unique identifier for the action by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the action in the myCustomMenus namespace.

Example:

"myCustomMenus.myMenuItem":
{
  "type": "MenuItem",
  "when": "selection.isAnyBlock",
  "action":
  {
    "name": "myCustomMenus.myAction",
    "type": "Action",
    "text": "Resize all blocks to fit content",
    "description": "Resize all blocks in current system to fit values displayed on block icons",
    "callback": "myCustomMenus.myFunction"     
  }
}

Reference to JSON object literal

Define the action separately from the widget and then reference the definition from the action array. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.

Example:

"myCustomMenus.myMenuItem":
{
  "type": "MenuItem",
  "action": "#myCustomMenus.myAction",
  "when": "selection.isAnyBlock"
},

"myCustomMenus.myAction":
{
  "type": "Action",
  "text": "Resize all blocks to fit content",
  "description": "Resize all blocks in current system to fit values displayed on block icons",
  "callback": "myCustomMenus.myFunction"
}

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`SplitItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"SplitItem"`

Type of configurable element, specified as "SplitItem".

`popup` — Widgets in `SplitItem` popup (required)
JSON array literal

Widget in the SplitItem popup, specified as a JSON string containing a reference to a JSON object literal.

Define the widget separately from the SplitItem container and then reference the definition from the popup value. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.

"myCustomMenus.mySplitItem":
{
  "type": "SplitItem",
  "action": "#myCustomMenus.myAction",     
  "popup": "#myCustomMenus.myMenu"
},

"myCustomMenus.myMenu":
{
  "type": "Menu",
  "sections":["#myCustomMenus.myMenuSection"]
}

`action` — Action to assign to widget (required)
JSON array literal

Action to assign to the widget. You can assign the action of one of the default widgets in the context menu, or your own custom action

To assign the action of a default widget, look up the name of the action using the slUIDeveloperMode function. Then, set the action value to the name, specified as a JSON string.

Example:"#mw.simulink.editor.selectAllAction"

To assign a custom action, set the action value to a JSON array literal that contains one of the following:

JSON object literal
Define the action directly inside the action array. Provide a unique identifier for the action by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the action in the myCustomMenus namespace.
Example:
```
"myCustomMenus.mySplitItem":
{
  "type": "SplitItem",
  "popup": "#myCustomMenus.myMenu",
  "action":
  {
    "name": "myCustomMenus.myAction",
    "type": "Action",
    "text": "My Action",
    "callback": "myCallback"
  }
}
```
Reference to JSON object literal
Define the action separately from the widget and then reference the definition from the action array. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.mySplitItem":
{
  "type": "SplitItem",
  "action": "#myCustomMenus.myAction",     
  "popup": "#myCustomMenus.myMenu"
},

"myCustomMenus.myAction": 
{
  "type": "Action",
  "text": "My Action",
  "callback": "myCallback"
}
```

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`DropDownItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"DropDownItem"`

Type of configurable element, specified as "DropDownItem".

`popup` — Widget in `DropDownItem` popup (required)
JSON string

Widget in the DropDownItem popup, specified as a JSON string containing a reference to a JSON object literal.

Define the widget separately from the DropDownItem container and then reference the definition from the popup value. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.

Example:

"myCustomMenus.myDropDownItem":
{
  "type": "DropDownItem",
  "action": "#myCustomMenus.myAction",     
  "popup": "#myCustomMenus.myMenu",
  "when": "selection.isIf"
},

"myCustomMenus.myMenu":
{
  "type": "Menu",
  "sections":["#myCustomMenus.myMenuSection2"]
}

`action` — Action to assign to widget (required)
JSON array literal

Action to assign to the widget. You can assign the action of one of the default widgets in the context menu, or your own custom action

To assign the action of a default widget, look up the name of the action using the slUIDeveloperMode function. Then, set the action value to the name, specified as a JSON string.

Example:"#mw.simulink.editor.selectAllAction"

To assign a custom action, set the action value to a JSON array literal that contains one of the following:

JSON object literal
Define the action directly inside the action array. Provide a unique identifier for the action by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the action in the myCustomMenus namespace.
Example:
```
"myCustomMenus.myDropDownItem":
{
  "type": "DropDownItem",     
  "popup": "#myCustomMenus.myMenu",
  "when": "selection.isIf",
  "action":
  {
    "name": "myCustomMenus.myAction",
    "type": "Action",
    "text": "If Expression" 
  }
}
```
Reference to JSON object literal
Define the action separately from the widget and then reference the definition from the action array. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.myDropDownItem":
{
  "type": "DropDownItem",
  "action": "#myCustomMenus.myAction",     
  "popup": "#myCustomMenus.myMenu",
  "when": "selection.isIf"
},

"myCustomMenus.myAction": 
{
  "type": "Action",
  "text": "If Expression"
}
```

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`Menu`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"Menu"`

Type of configurable element, specified as "Menu".

`sections` — Widgets in `Menu` container (required)
JSON array literal

Widgets in the Menu container, specified as a JSON array literal that contains one of the following:

JSON object literals
Define the widgets directly inside the sections array. Enclose the JSON object literals in brackets even if there is only one. If you chose this option, do not precede the JSON object literals with a key. Instead, provide a unique identifier for each widget by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the widget in the myCustomMenus namespace.
Example:
```
"myCustomMenus.myPopup":
{
  "type": "Menu",
  "sections":
  [
    {
      "name": "myCustomMenus.myMenuSection2",
      "type": "MenuSection",
      "items": ["#myCustomMenus.myMenuItem1","#myCustomMenus.myMenuItem2"]
    }
  ]
}
```
References to JSON object literals
Define the widgets separately from the Menu container and then reference the definitions from the sections array. Enclose the references in brackets even if there is only one. Specify each reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.myPopup":
{
  "type": "Menu",
  "sections":["#myCustomMenus.myMenuSection2"]
},

"myCustomMenus.myMenuSection2":
{
  "type": "MenuSection",
  "items": ["#myCustomMenus.myMenuItem1","#myCustomMenus.myMenuItem2"]
}
```

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`ButtonRowItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"ButtonRowItem"`

Type of configurable element, specified as "ButtonRowItem".

`text` — Widget label text (required)
JSON string

Widget label text, specified as a JSON string.

Example:"My Button Row"

`controls` — Widgets in `ButtonRowItem` container (required)
JSON array literal

Widgets in the ButtonRowItem container, specified as a JSON array literal that contains one of the following:

JSON object literals
Define the widgets directly inside the controls array. Enclose the JSON object literals in brackets even if there is only one. If you chose this option, do not precede the JSON object literals with a key. Instead, provide a unique identifier for each widget by specifying a value for the name property. Set the value to a JSON string containing a descriptive name for the widget in the myCustomMenus namespace.
Example:
```
"myCustomMenus.gainButtonRow":
{
  "type": "ButtonRowItem",
  "text": "Add Gain Blocks",
  "controls":
  [
    {
      "name": "myCustomMenus.gainButton1",
      "type": "PushButton",
      "action": "#myCustomMenus.add4Gains"
    }
  ]
}
```
References to JSON object literals
Define the widgets separately from the ButtonRowItem container and then reference the definitions from the controls array. Enclose the references in brackets even if there is only one. Specify each reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.gainButtonRow":
{
  "type": "ButtonRowItem",
  "text": "Add Gain Blocks",
  "controls":"#myCustomMenus.gainButton1"
},

"myCustomMenus.gainButton1":
{
  "type": "PushButton",
  "action": "#myCustomMenus.add4Gains"
}
```

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`PushButton`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"PushButton"`

Type of configurable element, specified as "PushButton".

`action` — Action to assign to widget (required)
JSON array literal

Action to assign to the widget. You can assign the action of one of the default widgets in the context menu, or your own custom action

To assign the action of a default widget, look up the name of the action using the slUIDeveloperMode function. Then, set the action value to the name, specified as a JSON string.

Example:"#mw.simulink.editor.selectAllAction"

To assign a custom action, set the action value to a JSON array literal that contains one of the following:

JSON object literal

Example:

"myCustomMenus.intButton1":
 {
     "type": "PushButton",
     "action":
     {
       "name": "myCustomMenus.add4Ints",
       "type": "Action",
       "description": "Add four Integrator blocks",
       "icon": "add-4.png",
       "callback": "plus4Ints"
     }
}

Reference to JSON object literal
Define the action separately from the widget and then reference the definition from the action array. Specify the reference as a JSON string containing the hashtag symbol # followed by the key of the JSON object literal you want to reference.
Example:
```
"myCustomMenus.intButton1":
 {
     "type": "PushButton",
     "action": "#myCustomMenus.add4Ints"
},

"myCustomMenus.add4Ints":
{    
    "type": "Action",
    "description": "Add four Integrator blocks",
    "icon": "add-4.png",
    "callback": "plus4Ints"
}
```

`when` — When widget is displayed (optional)
JSON string

The tables list the programmatic names of the conditions you can specify.

Some conditions pertain to block parameter values. To get the value of a block parameter, use the get_param function.

Conditions Related to Block Selection

When Condition is True	Condition
The current selection is a block.	`"selection.isAnyBlock"`
The current selection is a block of a type you specify.	`"selection.is<BlockType>"` For example: `"selection.isGain"`
The current selection is a masked block.	`"selection.isMasked"`
The current selection is a block that is linked to a library.	`"selection.isLibraryLink"`
The current selection contains only blocks whose `Commented` parameter has a value you specify, for example, the value `'on'`.	`"selection.Commented == <value>"` For example: `"selection.Commented == 'on'"`
The current selection is a block whose `Name` parameter has a value you specify, for example, the value `'Gain'`.	`"selection.Name == <value>"` For example: `"selection.Name == 'Gain'"`

Conditions Related to Subsystem Block Selection

When Condition is True	Condition
The current selection is a type of subsystem block you specify, for example, a Resettable Subsystem block.	`"selection.isAction"` `"selection.isArrayProcessing"` `"selection.isEnabled"` `"selection.isEnabledAndTriggered"` `"selection.isForEach"` `"selection.isForIterator"` `"selection.isFunctionCall"` `"selection.isNeighborhoodProcessing"` `"selection.isPixelProcessing"` `"selection.isReferenced"` `"selection.isResettable"` `"selection.isSimulinkFunction"` `"selection.isTriggered"` `"selection.isWhileIterator"`
The current selection is a virtual subsystem.	`"selection.isVirtual"`
The current selection is a Subsystem block whose `Permissions` parameter has a value you specify, for example, the value `'ReadOnly'`.	`"selection.Permissions == <value>"` For example: `"selection.Permissions == 'ReadOnly'"`
The current selection is a Subsystem block whose `ShowPortLabels` parameter has a value you specify, for example, the value `'FromPortIcon'`.	`"selection.ShowPortLabels == <value>"` For example: `"selection.ShowPortLabels == 'FromPortIcon'"`

Conditions Related to Selecting Multiple Model Elements

When Condition is True	Condition
The current selection contains more than one model element.	`"selection.isMultiselect"`

Conditions Related to Selecting Model Canvas

When Condition is True	Condition
The current selection is the model canvas.	`"selection.isEmpty"`

Conditions Related to Editor

When Condition is True	Condition
The editor shows the root model. For example, if you add a subsystem to a blank model, the condition is true when the editor shows the model and false when the editor shows the subsystem.	`"editor.isRoot"`
The editor shows the top model. For example, if you add a model reference to a blank model, the condition is true when the editor shows the model and false when the editor shows the referenced model.	`"editor.inTopModel"`
The editor shows a referenced model.	`"editor.inRefModel"`
The editor shows a referenced subsystem.	`"editor.inRefSubsystem"`
The editor shows a type of subsystem you specify.	`"editor.isAction"` `"editor.isArrayProcessing"` `"editor.isAtomic"` `"editor.isEnabled"` `"editor.isForIterator"` `"editor.isForEach"` `"editor.isFunctionCall"` `"editor.isNeighborhoodProcessing"` `"editor.isPixelProcessing"` `"editor.isResettable"` `"editor.isSimulinkFunction"` `"editor.isTriggered"` `"editor.isVirtual"` `"editor.isWhileIterator"`
The editor shows a Simulink Function.	`"editor.isSimulinkFunction"`

Conditions Related to the Model

When Condition is True	Condition
The top model of the current system is a model, as opposed to a library model or a subsystem model.	`"model.isModel"`
The top model of the current system is a library model.	`"model.isLibrary"`
The top model of the current system is a subsystem model.	`"model.isSubsystem"`
The top model of the current system is a test harness model.	`"model.isTestHarness"`

Example:"selection.isConstant || selection.isMasked" is true when the selection is a Constant block or when the selection is a masked block

`Action`

`name` — Unique identifier (required for nested arrays)
JSON string

Unique identifier specified as a JSON string containing a descriptive name in the myCustomMenus namespace.

`type` — Type of configurable element (required)
`"Action"`

Type of configurable element, specified as "Action".

`text` — Widget label text (required for `MenuItem`, `SplitItem` and `DropDownItem` widgets)
JSON string

Widget label text, specified as a JSON string.

Example:"My Widget"

`description` — Widget tooltip text (optional)
JSON string

Widget tooltip text, specified as a JSON string.

Example:"My widget takes this action"

`icon` — File path of icon image file (required for `PushButton` widgets)
JSON string

You can only assign custom icons to PushButton widgets. To assign a custom icon, set the icon value to the file path of the image file relative to extensions.json as a JSON string. The image file must be a PNG, SVG, or JPG file.

To assign the action of an existing icon, specify the icon name as a JSON string. You can look up the icon name using the slUIDeveloperMode function.

Example:"icons/my-action-icon.png"

`callback` — MATLAB function that takes widget action (optional)
JSON string

Name of the MATLAB function that takes the action you assign to a widget, specified as a JSON string. The string must be a valid input to the feval function. The function must be on the MATLAB path.

For example, suppose there is a MATLAB function named DispHello on the MATLAB path:

function DispHello
    disp("Hello World!")
end

To specify the value of the callback property value using this JSON declaration:

callback = "DispHello"

Setting the callback value to the name of a MATLAB script is not supported. Setting the callback value to a command is also not supported. For example, the callback value specified in this JSON declaration is invalid:

callback = "disp("Hello World!")"

Version History

Introduced in R2026a

RichMenu Extension

JSON Names of RichMenu Extension Points

Examples

Add Menu Items to Context Menu

Add Button Rows to Context Menu

Add Drop-Down Item to Context Menu

Assign Icons and Actions of Default Widgets to Custom Widgets

Properties

MenuSection

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "MenuSection"

items — Widgets in MenuSection container (required) JSON array literal

when — When widget is displayed (optional) JSON string

MenuItem

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "MenuItem"

action — Action to assign to widget (required) JSON array literal

when — When widget is displayed (optional) JSON string

SplitItem

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "SplitItem"

popup — Widgets in SplitItem popup (required) JSON array literal

action — Action to assign to widget (required) JSON array literal

when — When widget is displayed (optional) JSON string

DropDownItem

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "DropDownItem"

popup — Widget in DropDownItem popup (required) JSON string

action — Action to assign to widget (required) JSON array literal

when — When widget is displayed (optional) JSON string

Menu

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "Menu"

sections — Widgets in Menu container (required) JSON array literal

when — When widget is displayed (optional) JSON string

ButtonRowItem

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "ButtonRowItem"

text — Widget label text (required) JSON string

controls — Widgets in ButtonRowItem container (required) JSON array literal

when — When widget is displayed (optional) JSON string

PushButton

name — Unique identifier (required when defining a widget in the property values of another widget) JSON string

type — Type of configurable element (required) "PushButton"

action — Action to assign to widget (required) JSON array literal

when — When widget is displayed (optional) JSON string

Action

name — Unique identifier (required for nested arrays) JSON string

type — Type of configurable element (required) "Action"

text — Widget label text (required for MenuItem, SplitItem and DropDownItem widgets) JSON string

description — Widget tooltip text (optional) JSON string

icon — File path of icon image file (required for PushButton widgets) JSON string

callback — MATLAB function that takes widget action (optional) JSON string

Version History

See Also

Topics

`RichMenu` Extension

JSON Names of `RichMenu` Extension Points

`MenuSection`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"MenuSection"`

`items` — Widgets in `MenuSection` container (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`MenuItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"MenuItem"`

`action` — Action to assign to widget (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`SplitItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"SplitItem"`

`popup` — Widgets in `SplitItem` popup (required)
JSON array literal

`action` — Action to assign to widget (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`DropDownItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"DropDownItem"`

`popup` — Widget in `DropDownItem` popup (required)
JSON string

`action` — Action to assign to widget (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`Menu`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"Menu"`

`sections` — Widgets in `Menu` container (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`ButtonRowItem`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"ButtonRowItem"`

`text` — Widget label text (required)
JSON string

`controls` — Widgets in `ButtonRowItem` container (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`PushButton`

`name` — Unique identifier (required when defining a widget in the property values of another widget)
JSON string

`type` — Type of configurable element (required)
`"PushButton"`

`action` — Action to assign to widget (required)
JSON array literal

`when` — When widget is displayed (optional)
JSON string

`Action`

`name` — Unique identifier (required for nested arrays)
JSON string

`type` — Type of configurable element (required)
`"Action"`

`text` — Widget label text (required for `MenuItem`, `SplitItem` and `DropDownItem` widgets)
JSON string

`description` — Widget tooltip text (optional)
JSON string

`icon` — File path of icon image file (required for `PushButton` widgets)
JSON string

`callback` — MATLAB function that takes widget action (optional)
JSON string