enumeration Fails with get(), set() arguments

classdef XlBordersIndex < int32
  enumeration
    xlDiagonalDown      (5)
    xlDiagonalUp        (6)
    xlEdgeLeft          (7)
    xlEdgeTop           (8)
    xlEdgeBottom        (9)
    xlEdgeRight        (10)
    xlInsideVertical 	 (11)
    xlInsideHorizontal (12)
  end
end

Sample consumer routine

function SetBorder(sheetReference, ranges, border, weight, style)
% Usage
%  SetBorder(WorksheetObject, ranges, borderIndex, borderWeight, lineStyle)
% 
% sets the worksheet cell ranges specific border to the weight and style specified
%   ranges is a char string, cellstr, or array of cellstr or string ranges
%   borderIndex, borderWeight and lineStyle are scalar values

  if ischar(ranges), ranges=cellstr(ranges); end
  for i=1:numel(ranges)
    try
      theCell=sheetReference.Range(ranges{i});
      borders=get(theCell, 'Borders');
      thisBorder=get(borders, 'Item', border);
      set(thisBorder,'LineStyle', style,'Weight',weight);
    catch ME
      fprintf('Error in function SetBorder.\nError Message:\n%s\n', ME.message)
      %warning('Error in function SetBorder.\n%s\n', ME.message)
    end
  end
end

called as

  excel=actxserver('Excel.Application');
  wbk=excel.Workbooks.Open(outputFile);
  wksht=Excel_utils.sheetReference(excel,outputSheet);
  % draw border above totals row to show summations, payouts
  ixTotal=find(matches(cBill(:,matches(cBill(1,:),'Scholarship')),'Billing Total'));
  ixCols=find(matches(cBill(1,:),{'Student','Scholarship','Paid'}));
  addr=[cellstr(join(string([arrayfun(@(r) xlsAddr(r,ixCols(1)),ixTotal,'UniformOutput',false), ...
                            arrayfun(@(r) xlsAddr(r,ixCols(2)),ixTotal,'UniformOutput',false)]),':')); ...
                            arrayfun(@(r) xlsAddr(r,ixCols(3)),ixTotal,'UniformOutput',false)];
  Excel_utils.SetBorder(wksht,addr,XlBordersIndex.xlEdgeTop,XlBorderWeight.xlMedium, ...
                                   XlLineStyle.xlContinuous);

results in

  errorMessage =
    'Error in function SetBorder.
     Error Message:
     Error: Object returned error code: 0x800A03EC'

If one inserts

  if isenum(border), border=int32(border); end
  if isenum(weight), weight=int32(weight); end

before the loop, the function runs without error and successfully changes the desired cell range borders to style and type requested.

This seems to pretty-much negate the whole point of an enumeration -- is there any cleaner workaround?

Looks to me like a bug although I suppose since is external interface they can claim "unsupported" usage.

[dpb]

Oh. There's a secondary Q? here as well -- one will note the peculiar code in the catch clause of

    catch ME
      fprintf('Error in function SetBorder.\nError Message:\n%s\n', ME.message)
      %warning('Error in function SetBorder.\n%s\n', ME.message)
    end

The initial use of the warning() statement on its own caused me to not discover the above error for some time when looking at the resulting spreadsheet instead of letting me know when was created -- why is no warning message shown if write

    catch ME
      msg=sprintf('Error in function SetBorder.\nError Message:\n%s\n', ME.message);
      warning(msg)
    end

or the version with the formatting string inside warning() as the nag screen would have you?

Hence, just the expedient of fprintf w/o the trailing semicolon so see the message.

Answer 1

[dpb]

OK, I (finally!) figured out how to code the above to use a named constant with external interface -- don't use MATLAB enumeration but declare the constants as (Constant) in a class instead. ML enumerations are only useful inside MATLAB code that can and does interpret what an enumeration object is; don't try to use it elsewhere.

A sample class that does work is

classdef XlBorderWeight
  properties (Constant)
    xlHairline   =    1    % Hairline (thinnest border).
    xlMedium     =-4138    % Medium.
    xlThick      =    4    % Thick (widest border).
    xlThin       =    2    % Thin.
  end
end