Education/Projects/JetpackForLearning/DesignCamp/TechnicalQuestions

This page is a place for you to drop in solutions to common code problems that JfL projects face in their jetpacks during the Design Camp.

We encourage you to dump your code on etherpad.com or Github, and link to it here. The format on this page will be similar to a FAQ, with a question and answer. The answer can have a description of the soltion (optional) and a link to the code for the solution.

Example:

Q: How do I insert an image into a Web page?

A. First you need to get the document, then determine the insertion point using the DOM, and then do XYZ to insert the image. A code example is at: http://github.com/jflimageinsertion

Q: How do save the tab state for later recreation?

You can capture the current tab state information from "sessionstore.js". Recreating it is TBD, but see code at http://etherpad.com/OrGP3AA7F5 which reads the session store file and instantiates the JSON object.

Q: How do I see when a tab is opened (as opposed to when it's loaded)?

Use a progress listener (https://developer.mozilla.org/en/Code_snippets/Progress_Listeners) with an addTabsProgressListener https://developer.mozilla.org/en/Listening_to_events_on_all_tabs) called per window opened. Will post a Jetpack-specific example when written.

Q: How do I open a new tab with my blob of html as a page?

http://software.hixie.ch/utilities/cgi/data/data

Q: How do I access 'document' without security restrictions?

var doc = jetpack.tabs.focused.contentDocument.wrappedJSObject;