How do I communicate to the outside world from a Safari extension?

How would I let a running process know that 开发者_如何学编程a context menu has been clicked in Safari?

I've read that this is not possible due to security, but that seems wrong because 1Password somehow pulls all of the information from the desktop app's database into the Safari extension. I wrote the extension to display the context menu and was trying to send an XMLRPC request to localhost, but couldn't get it to work.

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I'm not certain of this, but I think 1Password does what it does by having a background process (1PasswordAgent) constantly polling for certain changes in the extension's local database and/or config files. For example, to initially get your passwords into the extension, the extension could set a certain flag in its localStorage db, which would get written (by Safari, not by the extension) to a file. The agent would then notice the flag in the file and copy your passwords from the main 1Password database into the extension's local database. Similarly, when the extension creates a new password entry, the agent would notice the change in the extension's database and mirror it to the 1Password database.

Perhaps you could do something similar?

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Although I have no idea about the implementation of 1Password, LiveReload achieves the same by using WebSocket to connect to a localhost URL (handled by the application). If you do it from the global page, cross-domain limitations do not apply, so you are free to connect to any URL:

var ws = new WebSocket("ws://localhost:98765");
...

(Be careful with that localhost thing, though, Chrome on Linux wants 0.0.0.0 instead of 127.0.0.1 or localhost. At least it used to want it.)