== Basic protocol ==

* Host opens <iframe> with the sandbox page's URL
* Sandbox initializes self, jQuery
* Host sees 'load' event on iframe
* Host posts message to sandbox: {action: 'load', code: '...js source...', args: ['...string...', ...]}
* Sandbox makes the 'args' parameter available as 'sandbox.args' in script's local context
* Sandbox executes the JavaScript code in its local context


== postMessage details ==

Send JSON-serialized strings of object maps, prefixed with 'mediawiki.embedscript:'

Host verifies the sandbox's messages by the origin window and the prefix.
Sandbox verifies the host's messages by the origin window and the prefix.


== Security ==

Security is enforced by the browser's same-origin controls. As such, protection against
malicious code can only be ensured by using a sandbox page hosted on a separate domain.

Remember that the code will have full capability to do anything the browser allows in
an iframe, including loading foreign scripts or sending all data passed into it to an
evil web site!

HTTPS is recommended for loading the sandbox page; the real sandbox page will never
send data passed to it on to any server, but a malicious MitM one might.


== Wiki-side usage ==

<embedscript arg1="arg1" ...>...JS code...</embedscript>

<embedscript src="ScriptPageName" />

Optional parameters:
* width - defaults to 640
* height - defaults to 480
* src - to load script source from a wiki page instead of contents
* fallback - fallback content if JS unavailable

Width and height default to 640x480


== File access ==

tbd