[whatwg] Inter-window communication beyond window.postMessage()

[Ian Hickson]

On Mon, 14 Sep 2009, Sidney San Martín wrote:
>
> The cross-document messaging API solves a lot of problems and is overall 
> an Awesome Thing, but requiring a reference to the target window is 
> hugely limiting. When a a window wants to talk to another window and 
> didn't create it, there are basically three options:
> 
> 1. window.open with a window name argument, which is a hack because the target
> window has to reload.
> 2. Comet, which is a horrible hack because a trip to the server is required.
> 3. LocalStorage and storage events, which wasn't designed for anything
> remotely like this.

4. Open a SharedWorker and send a MessagePort to the other window.


> Unless there's a reason to prevent free communication between windows, 
> there must be a better solution. I can think of a couple of 
> possibilities. The most obvious one would be an API similar to 
> postMessage that allows broadcasting of messages to all windows, windows 
> by name, and windows by domain. Another one (which I haven't developed 
> very far) would be to stick with window.postMessage but provide an API 
> to ask for windows. So, I could say, "Can I please have a reference to 
> the window named 'x'", or, "...to windows at 'example.com'", or, "...to 
> any window who'll give me one". Each window would obviously have to opt 
> into this.
> 
> What do you all think?

How do you know there's a Window to get a hold of if you don't have a hold 
of it already?

The main reason for Window.postMessage() is communication with iframes 
(gadgets), not with other top-level browsing contexts. What's the use case 
for the latter?

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
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Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'