1763137 - EventsDispatcher should filter Events by context descriptor

Status: RESOLVED FIXED

(Remote Protocol :: Agent, defect, P1)

Description

[Julian Descottes [:jdescottes]]

See https://phabricator.services.mozilla.com/D142514?id=564172#inline-788428

We are adding an EventsDispatcher utility to easily subscribe to internal events using session data. The API for this EventsDispatcher is: on(eventName, contextDescriptor, callback). However when an event comes up to the events dispatcher, we have no way to know if it actually matches the contextDescriptor for a given callback.

Imagine a situation where we have two callsites,for two different tabs:

this.messageHandler.eventsDispatcher.on("some-event", context1, cb1);
this.messageHandler.eventsDispatcher.on("some-event", context2, cb2);

Assuming context1 and context2 each correspond to a toplevel browsing context for a different tab. Today, when "some-event" is emitted from any of those tabs, both cb1 and cb2 will be triggered because we have no way to check where the event comes from.

We should:

• store the context descriptor next to the callback in EventsDispatcher
• attach the origin (message handler's type+id) to the event
• check if the event origin matches the context descriptor

Comment 1

[Julian Descottes [:jdescottes]]

Attachment: Bug 1763137 - [messagehandler] Filter events based on context descriptor used to subscribe to them

Depends on D155070

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a7f1e13009f6
[messagehandler] Filter events based on context descriptor used to subscribe to them r=webdriver-reviewers,whimboo

Comment 3

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/a7f1e13009f6