No more m-file app packaging...

Hi, is it correct that GUIs built programatically (as an m file using uicontrol) can no longer be converted to a mlappinstall file in 2025a? It seems like my GUI (PIVlab) can now only be shared on file exchange as a "pure toolbox" that will be installed in a completely "random" folder (/.../.../.../AppData/Roaming/.../.../.../.../...). None of my users (including me) will intuitively know how to start the GUI. In older releases, an App could be added to the "App badge", making it very easy for new Matlab users to start the GUI. But there doesn't seem to be a clean way to convert m-files to mlappisntall anymore. Previously an "App project" could be used together with the matlab.apputil.package could be used. Now Matlab tells me that "To package an app, create a MATLAB toolbox. "

I did that, but I cannot add an .m file as App.

Answer 1

[Nathan]

Hi William,

In R2025a, the workflow to share your MATLAB apps was unified with toolbox packaging to consolidate the sharable file artifacts, focusing on the MLTBX file. When packaging a toolbox, there is an option to select individual files from within your toolbox to display in the MATLAB App Gallery. These app files can be any executable MATLAB code file (M, MLX, MLAPP, P, MEX). These selected app files will register with the App Gallery in the same manner that MLAPPINSTALL files previously installed.

Please refer to the Add Install Actions (Optional) section of the documentation here:

https://www.mathworks.com/help/matlab/matlab_prog/create-and-share-custom-matlab-toolboxes.html

Additionally, if you have the app packaging PRJ file from a previous MATLAB release, you can use that as a starting point for packaging a toolbox in R2025a. Opening that file in R2025a will start an upgrade workflow and help bring your work into the new project-integrated workflow.

[William]

Hi Nathan, thanks, that sounds very good. I was reading the link you gave before asking my question, but it says:

"Specify the published MATLAB installable apps associated with your toolbox.

• To specify which apps (.mlapp files) are also installed and registered in the user's MATLAB apps gallery, click the Add button and select the apps. Alternatively, right-click the file in the Project panel, click Add Label, and select the App Gallery File label in the toolbox task menu.
• All .mlappinstall files in your toolbox folder are installed and registered in the user's MATLAB apps gallery."

... and therefore I thought I can only add mlappinstall files. I think this part of the documentation needs to be changed if it is true that you can add .m files too.

[William]

This doesn't work for my project. The m file I selected is not added to the Apps badge anywhere.

However, if I create a new project with minimum code files (just msgboxes), then it works as expected. Strange.

[William]

Now I created another fresh project file for my toolbox, and it seems to work! Is there a way to add an icon for the App that is added?

[Nathan]

Hi William,

You are right that there is a bug in the documentation. I will log that accordingly. Glad to hear you were able to get the app working though!

Currently, we do not have a method for customizing the icon for an included app in an MLTBX file. This is a limitation of the current approach and we are considering working this in for a future release.