How to propagate an event from the ModelListener to ALL presenters without the need to repeat the action in each presenter/viewer?

It does not make sense to propagate it to "all" presenters, because only one is active at any given time. Store the data in the model and notify the active presenter.

The thing to do here is make sure that each presenter contacts the model to update their state, so that when they're activated (activate() function), they're always up to date.

/Martin

Let's give an example to clarify the question: an emergency signal needs to be sent from "the rest" of the system, i.e. through the Model, and any active presenter should respond to it.

The point here is that: with an empty implementation of the propagating function, let say emergency_activate() in the modelListener, a "receiver" method has to be in each "Presenter", which calls let say activate_emergency() from the "Viewer."

What I am trying to explore here: is there a way to call the activate_emergency() from the modelListener rather than from the Presenter?

It has been mentioned in the documentation that the model has a pointer to the "active" presenter, right? If so, how can it be accessed? Can we use it to access members of the active Viewer as well?

Thanks

Hi @RMoha.2​ ,

The best way, as suggested by @Martin KJELDSEN​ , is to access the view using the presenter It might sound heavy on code, but is a sound approach from a design & maintenance point of view.

/Jagdish Bisawa

I agree with the point that is "heavy on code."

One way around it:

From TouchGFX Designer:

1- handle the action for this event in a custom container

2- make this container part of each screen. If not needed to be show, make it invisible

From Code:

1- maintain a pointer of this custom container in the Model (i.e. update this pointer in the Custom_Container::initialize() )

2- upon the event request: the Model calls the action through that pointer@

This way, the load is split between the designer and the code. Adding a new screen is seamless with the only extra step of adding the custom container.