returning a link to a named URL from a model function

Question

Hello all,

Well, it has finally happened, and I have stumbled across a problem for which no amount of googleing has helped. (Although I may simply be looking in the wrong direction, in which case, any pointers in the right direction would be great).

I am trying to find a way to return a link to a named url (with variable arguments) from a model's function. For instance, if I were to have the model:

class Picture(models.Model):
    picture_id = models.AutoField(primary_key=True)
    ...
    def picture_details(self):
        return "{%url picture_details " + str(self.picture_id) + " %}"

I would like to create a link for a Picture object 'pic' on the template:

   ...
   <a href="{{pic.picture_details}}" > details </a>
   ...

That links to the url named 'picture_details'. However, the resulting link in the template is 'http://.....{%url picture_details x %}' (x is the picture_id).

I understand using <a href = {% url picture_details pic.picture_id %} /> would work, however my situation is slightly different, as the links are part of a dynamically built image map. So, I would like the image map string:

    <area shape="some_shape" coords="some_coords" href="{{pic.picture_details}}"/>

to result in a link to the url named 'picture_details' with the argument picture_id.

I hope I have been able to explain my problem clearly, but if any more information is needed, please let me know. Many thanks in advance for any help,

greetz,

marc

Answer 1

You should use the reverse function in this case. Reverse is the view side counterpart of the {% url %} template tag.

from django.core.urlresolvers import reverse

class Picture(models.Model):
    picture_id = models.AutoField(primary_key=True)
    ...
    def picture_details(self):
        return reverse('picture_details', args = [self.picture_id])

From the documentation:

If you need to use something similar to the url template tag in your code, Django provides the following method (in the django.core.urlresolvers module):