Resize tracking is not working for multiple maps

[aparshin]

Test case: http://jsfiddle.net/cF2zZ/

If you will change page width, the top map updates property while the bottom one doesn't.

Probably, the proplem is that L.DomEvent doesn't allow to add listener multiple times to the same object (window in this case) for the same event type (resize).

[mourner]

You're right, confirmed. Hmm... A tricky problem. Should we stamp contexts and include them in the key too?

[fastrde]

sometimes it could be a desired behavior that a listener overwrites the previous added listener.
Is this behavior used in leaflet (perhaps unintentionally)?

The removeListener function has no context yet, so you can't remove a specific listener for a event type anymore.
Is the context available everywhere we have to/want to remove a listener?

[aparshin]

More solution variants:

• Add another optional parameter separateByContext (unfortunately, it increase number of addListener parameters)
• Add optional postfix to event type to separate different contexts (something like "resize:map1").
• Implement singleton, that will track window events and deligate them to all created maps (rather complex way)

[mourner]

I tried implementing a solution with context stamping if it is specified, but then found out that there is a lot of existing code (not only Leaflet but many plugins) in which DomEvent.removeListener doesn't have a context passed, and that means that this change will break a lot of plugins and will require all of them to update, which is not very desirable.

Considering this issue really only affects window resize, I'll try to wrap the passed listener so that it gets different ids.

[mourner]

Yep, works well with a very simple fix :)