Question

I’m developing extensions for Chrome, Safari and Firefox, and I need to add SWF file in my extension. I want to show it on a page. I read in documentation that I can store media files in Chrome and Safari extension.

Can I do the same with Firefox?

Answer 1

Yes, a Firefox extension can also contain any files you like. But you probably meant to ask: “Can I get a URL of a file in my extension that will be usable on a web page?” If you are using the Add-on SDK then it is simply:

var self = require("self");
var url = self.data.url("file.swf");

In a classic add-on it is slightly more complicated – chrome:// URLs normally cannot be used by web pages, for security reasons. You can however specify the contentaccessible flag for your namespace in chrome.manifest, e.g.:

content myextension chrome/content/ contentaccessible=yes

Then web pages will be able to use chrome://myextension/content/file.swf. The other option would be to register a resource:// namespace, these are always accessible from web pages.