Input and output arguments in App Designer

I am trying to make a GUI using App Designer in R2016a and can't figure out how to set input/output arguments. In GUIDE, there is the OpeningFcn that includes varargin for command line arguments, but I see nothing comparable in App Designer. I thought that adding the variables to the following part of code would work, but it is uneditable.

% Construct app
function app = MyApp()

As for the output, if I call the gui from the command line like this.

out = MyApp;

then out appears to be the entire app object. However, I would like to only output specific variables.

I have checked the examples provided and searched the mathworks site but haven't found an explanation.

-Neil

Answer 1

[Melissa Williams]

Hi Neil,

This isn't currently supported in App Designer for 16a. However it is on our radar and planned to be supported in an upcoming release.

Can you tell me more about what you are trying to do with output arguments?

-Melissa

[Chris Portal]

As of R2017b, input arguments can be passed into the app when the app is created.

Answer 2

[Sebastian Bech-Terkilsen]

Hi Neil,

If the output variable you want to transfer to your global workspace has public access in the app, then it is in the application structure, if you were to call the app like so:

   [output] = myapp; % without input arguments, myapp(input,input) with input arguments.

then your output variable is output.(variablename) I noticed though that it is only accessable while the app is open. So you may either assign a new variable like:

    newvariable = output.variable;

While the app is open (once you close the app the structure "output" remains but with an empty variable).

Your second option, more intuitive, is to create a button with a push callback as follows:

   assignin('base',variablename,variable) % saves the variable "variable" to the base(global) workspace with the name "variablename".

Answer 3

[Melissa Williams]

Neil,

Here's more on a work around for input arguments.

http://www.mathworks.com/matlabcentral/answers/284140-call-an-mlapp-with-input-argument-s

[Neil]

Thanks Melissa. Chris' workaround should suffice.

Answer 4

[Geoffrey Vincent]

Hello, The app designer editor is locked. But you can copy-paste all the code in a classic .m file.

After this you can pass arguments through the constructor and the output method of the app class.

But if you still want to edit the GUI with the design view you cannot re-copy-paste the code inside the designer editor. So do the trick only when your GUI is close to be finish.

Answer 5

[Tim Van Poucke]

Is in 2017b the problem already resolved, that there can be output from the app?