How I change a block mask programmatically using a Level 2 Matlab S function?

I would like to change items in a block mask for a Level 2 Matlab S function using the S function.

For example, I have an S function that reads a file and sets the number of outports based on the data in that file. I have a mask on that S function block. How do I configure the port labels of the mask using the S function. Using callbacks in the mask would be acceptable.

I have tried set_param(gcb, 'MaskDisplay', display_code) in the setup function of the S function code but ended up in an unrecoverable recursion situation.

I was going to try to use a callback in the mask itself but have not found a good way to get the data from the S function to the callback.

Answer 1

[MC]

I figured it out. I used "Simulink.Mask..." to set the property of the mask in the S function setup which doesn't seem to trigger the S function to run like set_param does.

mask_object = Simulink.Mask.get(gcb);
display_script = mask_object.Display;

Do some stuff to the value of display_script

mask_object.Display = display_script;