Developer's Guide

This page explains how the VPython question type works.

1) init_vpython

The init_vpython function defined in preload.py handles the following:

1. CSS styling of the GlowScript simulation components & importing of the GlowScript scripts required to make and display the simulation
2. Custom logic to ensure that only one GlowScript simulation is running at a time
3. Bugs with conflicting versions of MathJax

This function must be called in content.catsoop using a <python> element.

2) vpython.py

2.1) Defaults

The vpython question type extends the built-in pythoncode question type. The question uses two new variables, csq_vpython_pre and csq_vpython_post, which are analogous to csq_code_pre and csq_code_post. The difference is that csq_vpython_pre and csq_vpython_post are used by handle_check to generate the GlowScript simulation response, whereas csq_code_pre and csq_code_post are used by handle_submit to grade submissions.

2.2) Code Injection

This question type expects csq_name to have the format X_Y where X is any string and Y is an integer. This format enables a vpython question to get a user's submitted code for all questions with a matching X and smaller Y value. Those code submissions are then injected into the simulation code in handle_check wherever that submission's corresponding csq_name is found.

2.3) GlowScript

The handle_check function returns a JavaScript <script> element which compiles the submitted Python code into JavaScript and uses it to generate the GlowScript animation in the response.