Statistic module: sixth week update

This is an update of my work on statistic module for Melange.

Basically for the last week I studied JavaScript. It mostly included more advanced programming techniques like anonymous functions (function () {})() or closures, learning jQuery library and learning how it is all constructed in Melange source code. I am very grateful to Mario for all his explanations and for giving me links to some very interesting resources.

So my first JavaScript task was to make 'Task' button on the collect_stats page work in AJAXy way. Before that, it started stats collecting task and the page was reloaded which was completely unnecessary. I changed it so that the Task button generates XMLHttpRequest and also some message is shown after a task is successfully started. Work on that button took me more time that I expected. Anyway, it was my first jQuery job which I did mostly on my own. Before that week JavScript was rather like a strange Java to me and now I am exploring more and more advantages of it. I am sure that my efficiency will improve (and based on this week I am right :-)

Then I started to help with work on statistic dashboard page. Anyway, the first task that I assigned myself came out to be too ambitious. I wanted to fix a bug that when a widget with a pie chart visualization is moved, the pie chart disappears. I could not find a place in code which was responsible for it. The problem was also that only pie chart disappeared while everything with tables was fine. Fortunately this bug does not have a very high priority at this stage, so I put off working on it and moved on to some simpler but more important tasks.

On the backend side we mainly worked on integrating it with frontend. Some methods were added to statistic_chart view - they were needed for generating json responses for frontend ajax calls. Most of these methods were implemented by Mario and I hope it helped him to get more involved in Python side of module.

Apart from direct work on statistic module I created wiki page on introducing Task Queue API in Melange and how I imagine it. Thank you for all comments, I will try to work on that and improve it as soon as possible.