Using web workers with Sencha Touch 2

2
votes

Premise: A complete Sencha touch/Js noob with a Java background - (5 days)

Is it possible to use HTML5 web workers with Sencha Touch? The scenario I have is, I have an app made with Sencha Touch 2 and packaged with phone gap and in one of the scenarios, on clicking a button a controller makes an API call which renders the UI inactive for a little bit - I would ideally like to move this to a secondary thread and keep the UI as responsive as possible, but since JS is single threaded I want to leverage HTML5 webworkers for Sencha touch . I found this plugin but can I use this with Sencha Touch 2 ? If not what are the other options I have. Mind you this is for mobile/tablet dev with Sencha touch and not extJS for desktops.

1
javascriptextjssencha-touch-2web-worker

1 Answers

5
votes

What I've understood from your question is that you want to use webworkers to render UIs, right? I think it's impossible because the scope of webworkers is very limited. Here's the list of things that webworkers can access:

  • The navigator object
  • The location object (read-only)
  • XMLHttpRequest
  • setTimeout()/clearTimeout() and setInterval()/clearInterval()
  • The Application Cache
  • Importing external scripts using the importScripts() method
  • Spawning other web workers

And this is the list of things that webworkers can't access:

  • The DOM (it's not thread-safe)
  • The window object
  • The document object
  • The parent object

Follows a list of webworkers use cases:

  • Prefetching and/or caching data for later use
  • Code syntax highlighting or other real-time text formatting
  • Spell checker
  • Analyzing video or audio data
  • Background I/O or polling of webservices
  • Processing large arrays or humungous JSON responses
  • Image filtering in
  • Updating many rows of a local web database

For more informations about webworkers and their enviroment: http://www.html5rocks.com/en/tutorials/workers/basics/

Talking about my extension: I don't think it goes well for Sencha because it uses Ext structures and classes.

In the end, I don't know any Sencha UX for webworkers.

UPDATE (2013/03/20)

ExtJS-WebWorker now works for Sencha Touch too!