Matlab - app designer - component name and callback

Hi,

In App Designer

How can we know the name of a modified component when his callback is also connected to other component ?

Thks

[Adam Danz]

Are you asking how to idenitify which component invoked a callback function in the case where multiple components are assigned the same callback function?

[patrick bouche]

Yes!

Answer 1

[Adam Danz]

The 2nd input to a callback function in App Designer is "event'. event.Source is the handle to the object that invoked the callback function. event.EventName is the name of the event (a string).

objHandle = event.Source;
objName = event.EventName; 

[patrick bouche]

I am sorry but it doesn't work

event.EventName give 'ValueChanged'

[Guillaume]

Yes, EventName is the name of the event, and it's useful if the same callback is used to catch different types of events. It has nothing to do with what object triggered the callback,

However, as Adam said, the Source property is the handle to the object that triggered the callback so that's what you should use.

[Adam Danz]

Objects don't really have names. However, you can assign most (all?) objects a name by assigning a string to their Tag property. Then you can identify the object by its tag like this

objHandle = event.Source;
objHandle.Tag

If you haven't assigned a Tag, the tag property will be empty.

[René Lampert]

Hy Guillaume,

could you please explain in detail what you mean with " it's useful if the same callback is used to catch different types of events. " I dont get the point out of this phrase. Do you have a minimal example fot this?