App Designer - How do I pass a structure or array from one app to another?

I'm developing an app to process laboratory test data that will use several auxilary apps for different stages of the processing. I initially load the data file into the main app, apply some corrections/calibrations, and store it in a public structure within the main app. I want to pass that structure to a secondary app for more analysis.

I've seen many examples of passing a single value from one app to another, e.g., values from an edit field. I've used that coding approach in other places in my app and it works fine. I'm not able to find any examples of passing arrays or structures between apps. When I try to use the same approach to pass a structure, I'm getting error messages like:

Unrecognized method, property, or field 'structure' for class 'main'.

Does passing a structure work the same way or am I missing something?

Answer 1

[Kevin Holly]

The link below demostrates how to communicate between apps when using app designer.

https://www.mathworks.com/help/matlab/creating_guis/creating-multiwindow-apps-in-app-designer.html

[RGB85]

Kevin, thank you for the reply. I had read through this section previously and was still not understanding. In the link there is the following code:

function ButtonPushed(app,event)
updateplot(app.CallingApp,app.EditField.Value,app.DropDown.Value);
end

I am able to use code similar to this to pass individual values. My problem is with passing data that are not associated with app elements. For example, instead of passing the value of an edit field (app.EditField.Value above), I want to pass a public structure containing a 6x10000 matrix.

My code is shown below,

 function CaculateCcMenuSelected(app, event)
 exportdata(app.CallingApp, app.data)      
 end

where app.data is the public data structure. I am getting the error message "Unrecognized function or variable 'app.data'."

Please let me know if you have any suggestions or if my explanation of the issue is unclear.

[Kevin Holly]

Have you defined data as a property as such?

properties (Access = public)
       data
end

[RGB85]

I have data defined as:

properties (Access = public)
        data = struct(); % Description
end

because data is a structure that is shared and populated within the main app. Do I need to create a separate property for passing to another app?

[Kevin Holly]

You will need to define the other app as a property.

properties (Access = public)
    data = struct(); % Description        
    CallingApp % Main app object
end
    

Is data first defined in the main app?

I want to make sure the data isn't stored in app.CallingApp.data for instance.

[RGB85]

I believe the data is first defined in the main app. I probably haven't provided enough information in my previous posts. I've pasted all of the pertinent code from both the main app (CRSMain) and the auxillary app (CalcCc) below.

Code in CRSMain (I want to send the data structure app.data from here to CalcCc).

    properties (Access = private)
        CalcCc %Calculate Cc auxillary app
    end
    
    properties (Access = public)
        data = struct(); % public data structure defined in CRSMain to store imported data
    end

The CalcCc auxillary app is opened from the menu selection shown below, and app.data is what I want to send to CalcCc.

    function CaculateCcMenuSelected(app, event)
        app.CalcCc=CalcCc(app,app.data);
    end

Code in the CalcCc auxillary app (I want to receive app.data from CRSMain)

    properties (Access = private)
        callingapp% Description
    end
        
    properties (Access = public)
        data = struct();
    end      

Startup function in CalcCc

    function startupFcn(app, CRSMain, datafromCRSMain)
        app.callingapp = CRSMain;
        app.data = datafromCRSMain; 
    end

When I activate CaculateCcMenuSelected in CRSMain, I get the following error.

Error using CalcCc/startupFcn (line 28)

Unrecognized property 'data' for class 'CalcCc'.

Error in CalcCc (line 90)

runStartupFcn(app, @(app)startupFcn(app, varargin{:}))

Error in CRSMain/CaculateCcMenuSelected (line 362)

app.CalcCc=CalcCc(app,app.data);

Error using matlab.ui.internal.controller.WebMenuController/fireActionEvent (line 67)

Error while evaluating Menu Callback.

[Kevin Holly]

Do the following and let me know if it works:

CRSMain

    properties (Access = private)
        CalcCc % Calculate Cc auxillary app
    end
    
    properties (Access = public)
        data = struct(); % public data structure defined in CRSMain to store imported data
    end

    function CaculateCcMenuSelected(app, event)
        app.CalcCc=CalcCc(app,app.data);
    end    

CalcCc

    properties (Access = private)
        callingapp % Description
    end

        function startupFcn(app, CRSMain)
            app.callingapp = CRSMain;
            app.callingapp.data % This should display your data in your command window. You can access your data with app.callingapp.data
        end

[RGB85]

I updated to what you have above and am now getting the error:

Error using CalcCc (line 90)

Too many input arguments.

Error in CRSMain/CaculateCcMenuSelected (line 370)

app.CalcCc=CalcCc(app,app.data);

Error using matlab.ui.internal.controller.WebMenuController/fireActionEvent (line 67)

Error while evaluating Menu Callback.

[Kevin Holly]

I meant to remove the app.data. sorry about that.

function CaculateCcMenuSelected(app, event) 
    app.CalcCc=CalcCc(app); 
end

[RGB85]

That worked! Thanks Kevin - I appreciate your help!