Adder: revision

"""Perform addition using Django:Revision
"""
#{% url add %}pointing to add method by explicitly naming url
template = """<form method="post" action={% url add %}>{% csrf_token %}
        <input type="text" name="a" value={{ a }} > + <input type="text" name="b" value={{ b }} >
        <input type="submit" value="="> <input type="text" name="result" value={{ result }}>
    </form>"""

def add(request):
    try:
        a = int(request.POST.get('a', 0))  #set default to 0 instead of deprecated has_key()
    except:
        a = 0           # set to 0 if no valid value
    try:
        b = int(request.POST.get('b',0))
    except:
        b = 0
    t = Template (template)
        c = RequestContext(request, {'a': a, 'b': b, 'result': a+b})
    return HttpResponse(t.render(c))

#url.py
urlpatterns = patterns('',
    url(r'^add/$', 'myapp.views.add', name='add'),
)