Matlab app - Using properites(app) opens another instance of the app

Hello, I am trying to write a function that will save apps properties to a .mat file. To do this I have called properties(app) and then loop over these properties until I get the the properties I want to save. However, my function causes another window of the app to open. After some troubleshooting I realise that this occurs when properties(app) is called. my code is included below for clarity.

function savesimfile(app, filename, fileloc)
props = properties(QFM3);
savestate = 0
savestartmarker = 'SaveDataStart'
for iprop = 1:length(props)
    ipropname = props{iprop}
    if ipropname == savestartmarker
        savestate = 1               
    elseif savestate == 1
        disp(ipropname)
    end
end     
end

[Image Analyst]

Give an example of what you pass in for the app, filename, fileloc variables. How do you actually call that function?

[Walter Roberson]

props = properties(QFM3);

Is QFM3 the name of the class? If so then that statement would be calling the class constructor.

[Thorne Hanna-Spain]

Thanks for responding. I am new to matlab app design and classes in general. QFM3 is the name of the app and the name of the 'primary' class. My variables are stored in properties of this class alongside other properties matlab app uses to construct the app gui. Is there a way to just access this properties? I have included code to help discribe this structure below:

classdef QFM3 < matlab.apps.AppBase
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure                        matlab.ui.Figure
        FileMenu                        matlab.ui.container.Menu
        ...
    end
    properties (Access = public)
        % my properties
        SaveDataStart = 0
        SimFileName = ''    %Simulation File Name
        ...

Answer 1

[Walter Roberson]

Change

props = properties(QFM3);

to

props = properties(app);

This assumes that savesimfile is a method of class QFM3.

[Thorne Hanna-Spain]

Hi Walter. Thank you this solution it works perfectly!