GSoC/GCI Archive
Google Code-in 2011 LimeSurvey

Port Expression Manager to Yii Framework - Integration

completed by: Gautam

mentors: TMSWhite

LimeSurvey 2.0a (our latest development release) is based on the CodeIgniter framework. Unfortunately the CodeIgniter license is not compatible to the LimeSurvey GPL license so we need to port the LimeSurvey codebase to a new framework, Yii. We need your help to do this.

General Steps:

  • Install a subversion client and download LimeSurvey 2.0a (that's the version still based on CodeIgniter) using subversion and install it by running http://<yourserver>/limesurvey/index.php/admin
  • Do the same with the new LimeSurvey development branch based on Yii. There is no installer yet so just point the database configuration in /application/config.php to the database you created in step 1.
  • Check out the functionality named in this task title in the CI version. If you have problems to find it please get in touch with us on IRC.
  • Check out the source code and then port the functionality to Yii.
  • Test the new functionality in the Yii version thoroughly.
  • Submit a patch created with subversion and based on the YII branch to this task idea and wait for feedback.

Specific Steps for This Task

  • Review the Expression Manager (EM) documentation and survey-building how-tos, and notes for developers.
  • For this task, specifically port all calls to LimeExpressionManager::XXX() functions to Yii framework.
    • There are approximately 100 insertion points of EM into the CI branch, spanning 30 files.  Each of these needs to be ported to Yii
    • This is largely a find and cut/paste task, but needs to be validated, since variable names and calling parameters may change in Yii
  • Ensure that the Yii port and _CI branch tests produce identical results.


  • Good PHP knowledge
  • Experience with a PHP MVC framework


  • We want a straight port. Don't start to rewrite big portions of the code.
  • If you can clean up the models it would be great but it is not necessary.
  • It is important that you test your ported code thoroughly before you submit the patch. This will save you and us alot of time. It will take longer to accept your patch if you did not test.