I would like to build an Firefox extension which after users click it, a web page is dynamically constructed and opened in a new tab.
In "tab" API, I only saw tab.open() open a hyperlink to a remote website. Can I construct a JavaScript variable contains all the HTML contents (Like var page = "blahblah....") and open it? How to do that?
You don't have to dynamically construct it, just put a htm page in your addon and then the link to it will be resource://your addon id/blah.htm. This addon here creates a page: addons.mozilla.org/en-US/firefox/addon/twitch-alarm
You can also create an about:blah url to your page, this shows how to do it without the sdk: github.com/Noitidart/ZooniverseXpert