Question

I am trying to assign some javascript variables in a Django template.

I am having a problem where the values I am assigning are being written to the page properly (I can see them in the page source), but still come up as null.

I am doing this:

<script type='text/javascript'>   var coords = [];   {% for i in item_list %}     coords.push([ {{i.x}}, {{i.y}} ]);   {% endfor %} </script> 

This is the page source that is produced:

coords.push([ -320.435118373, -149.333637576 ]); coords.push([ -120.41321373 , -329.312376 ]); ... 

It seems to be perfectly valid javascript, however, using Firebug to view the value of coords, this is what is produced:

[[null, null], [null, null], [null, null]...[null, null]] 

So it’s apparent that each of the push() calls is going off correctly and a new array of size 2 is being added each time. However, for some reason, the numeric literals all evaluate to null.

Does anyone know how I can get these values to be used properly?

UPDATE: It appears that the values in the array are fine until I pass them into the jQuery flot plugin:

$.plot($('#mapWrapper'), coords, options); 

So I guess this doesn’t have anything to do with the way I am using the Django templates after all. Still, I am curious as to what the problem is with $.plot.

Answer 1

Looks like I was missing one small thing. I was using a data series which was an array of arrays. Actually, the jquery flot plugin is expecting an array of series, which are arrays of arrays, so I needed a triple-nested array.

Changing from this:

$.plot($('#mapWrapper'), coords, options); 

to this:

$.plot($('#mapWrapper'), [coords], options); 

fixed the problem.

Thanks to all who looked at this.