writing urlpattern in django for rendering an image

Question

in my django app,I have an index page which lists some summary info which is dynamic(based on some user input data in db) . I have coded it as below

views.py

def custom_render(request,context,template):
    req_context=RequestContext(request,context)
    return render_to_response(template,req_context)

@login_required
def index(request, template_name):
    summary_info = get_summary(...)
    return custom_render(request,{'summary':summary_info},template_name)

urls.py

urlpatterns=patterns('', 
     ...
    url(r'^$', 'myapp.views.index',dict(template_name = 'myapp/index.html'), name = 'home'),
...

Now,I want to include a chart image generated by matplotlib on the home page..So,when user requests the index page url, he can see both the summary info and the chart

I have written the index.html as below

{% extends "myapp/base.html" %}
....
<div id='summary'>
{# here display the summary #}
...
</div>

<div id='chart'>
<img class="chartimage"src="{% url myapp_render_chart %}"            
    alt="chart"            
   />
</div>

The chart view is

def render_chart(request):
    data = get_data(request.user)
    canvas = None
    if data:
        canvas = create_piechart(data)
    response = HttpResponse(content_type = 'image/png')
    if canvas:
        canvas.print_png(response)
    return response

import matplotlib.pyplot as plt
def create_piechart(data,chartsize=(16,16)):
    ...
    figure = plt.figure(figsize = chartsize)
    plt.pie(fracs, labels=labels, autopct='%1.1f%%', shadow=True)        
    canvas = FigureCanvas(figure)
    plt.close(figure)
    return canvas

I am not sure how I should do the urlmapping.The url r'^$', is already mapped to the index page.But I need to create a url(...) in urlpatterns sothat the view render_chart() is associated with the name myapp_render_chart and so can be called within {% url %} tag . Can someone pls help me with this?

Answer 1

So you just want another url mapping? It wouldn't be very different from the one you already have. e.g.:

urlpatterns = patterns("myapp.views",
    url(r'^$', 'index',dict(template_name = 'myapp/index.html'), name = 'home'),
    url(r'^kick-ass-chart/$', 'render_chart', name='myapp_render_chart'),
)