User input folder path in App Designer with multiple tables

First time using this feature. I'm trying to have the user input their folder path and will display the calculation based on it.

I have the calculation code on a seperate file that is called when the calculate button is pressed.

function calculation(folderpath)

But other than that I'm not sure how to have

1. what the user input = folderpath so the function can be run
2. how to display the data in the correct table location

[Geoff Hayes]

@Emily - how does the user enter the folder path? Should they use uigetdir to populate that path text control?

[Emily]

They just copy/paste the folder path directly into the text box.

Answer 1

[Jon]

You need to define a value changed callback function for each Edit Field, something like this for the first one, and then similar for the second one, except change the names appropriately, e.g. app.EditField -> app.EditField2

, app.UITable.Data ->app.UITable2.Data

    % Callbacks that handle component events
    methods (Access = private)

        % Value changed function: EditField
        function EditFieldValueChanged(app, event)
            % get the folder path that the user entered
            folderpath = app.EditField.Value;
            % calculate the data using the data in this folder
            data = calculation(folderpath)
            % display the data in the appropriate table
            app.UITable.Data = data
            
        end

[Jon]

Although the above approach is straightforward it requires essentially duplicating the same code twice, which isn't really very good practice. If you want to get more sophisticated you could use a single, common callback for when either edit box was changed and then assign the data to the appropriate table. To do this assign Tag names to each edit field. You can look at the event data passed to the EditFieldValueChanged function, specifically data.Source.Tag to see which one was called and branch accordingly to populate the correct table.

[Emily]

Hi, I tried out this method and it's giving me some errors.

Error using calculation

Too many output arguments

Error sandbox/ButtonPushed

data=calculation(folderpath);

Error using matlab.ui.control.internal.controller.ComponentController/executeUserCallback

Error while evaluating Button PrivateButtonPushedFcn

I tested out the calculation code again and it seems to be working and printing the cell arrays properly.

[Jon]

The error message is telling you that your function, calculation, is not returning any output arguments, but you try to assign a value to the output, in your line

data=calculation(folderpath);

Please check that in your code for calculation that the first line assigns an output argument to the result of the calculation, that is the for example:

function outData = calculation(folderpath)
    inData = readmatrix(fullfile(folderpath,'myData.csv'))
    outData = inData*2; % just for example
end

If that doesn't fix your problem, please attach your code along with any necessary files to run it and I will see what is going on.