matlab: missing emxAPI header file during webcoder's build compilation (Generate Javascript Using Matlab Toolbox)

emxapi_webcoder_fix.m

%% BUG:

% Struggled with this for quite sometime, while trying out the MouseEvent, Event et al. Callback example 
% in the 'CreateAppWithCallbacks' demo example. The bug was a missing emxAPI header file during build compilation

SOLUTION:

%% 1.1 Fix dynamically allocated arrays to use EMXARRAY
% - Use this to prevent webcoder compile errors
% WebCoder Bug:
% - configured by author to use c-style emxarray data structure,
% as was probably, the default in 2019.
% - unfortunately, mathworks introduced coder::array class template to be
% the default, when target language is C++
%
% See:
% - https://www.mathworks.com/support/search.html/answers/516820-matlab-2020a-matlab-coder-use-c-style-emxarray-bug.html
% - https://www.mathworks.com/help/coder/ug/use-dynamically-allocated-cpps-arrays-in-generated-function-interfaces.html
ccfg = coder.load('CodeConfig.mat');
ccfg.codeConfig.DynamicMemoryAllocationInterface = 'C';
save('CodeConfig.mat', '-struct', 'ccfg');