System messages should be pluged into the application manifest

[mounirlamouri]

[marcoscaceres]

Can you clarify what you mean by "plugged"?

[mounirlamouri]

In Firefox OS we have:

"messages": [
  [ "foo", "/index.html" ],
  [ "bar", "/blah.html" ]
],

The current spec doesn't say how you register to get system messages.

[jmajnert]

OK. So the setMessageHandler() doesn't actually register for a message? It only sets a handler for messages that the application had previously registered for via the manifest?

[mounirlamouri]

Yes.

[jmajnert]

OK. Then I think we should clarify that in the runtime spec. The current text gives no hints as to how registering happens.

Why do you think the system messages should be declared in the manifest? Wouldn't a runtime API for registering/unregistering be enough?

[mounirlamouri]

We might need a runtime API too but we definitely need something in the manifest so I prefer to delay the JS API for when we will really need it.

I started writing something for that last week. I have to find time to finish it.

[jmajnert]

From the example you gave earlier I see that the registration is on a per-document basis - message of type "foo" goes to index.html and "bar" goes to blah.html. Could you please explain what the expected behaviour is if a "bar" message arrives when:

1. Application is not running (its manifest says "launch_path: 'index.html' "). Will the application launch normally and get redirected to blah.html (at what point?), or will it launch directly with blah.html?
2. Application is running, index.html is loaded. I guess the system message will have no effect until user navigates to blah.html?

[jmajnert]

I think this issue is also relevant here: #20

[jmajnert]

We should also consider multi-window scenarios as in #100