DRY URLs in Django Javascript

Question

I'm using Django on Appengine. I'm using the django reverse() function everywhere, keeping everything as DRY as possible.

However, I'm having trouble applying this to my client-side javascript. There is a JS class that loads some data depending on a passed-in ID. Is there a standard way to not-hardcode the URL that this data should come from?

var rq = new Request.HTML({
    'update':this.element,
}).get('/template/'+template_id+'/preview'); //The part that bothers me.

Answer 1

One of the solutions I came with is to generate urls on backend and pass them to browser somehow.

It may not be suitable in every case, but I have a table (populated with AJAX) and clicking on a row should take the user to the single entry from this table.

(I am using django-restframework and Datatables).

Each entry from AJAX has the url attached:

class MyObjectSerializer(serializers.ModelSerializer):
    url = SerializerMethodField()
    # other elements

    def get_url(self, obj):
       return reverse("get_my_object", args=(obj.id,))

on loading ajax each url is attached as data attribute to row:

var table = $('#my-table').DataTable({
   createdRow: function ( row, data, index ) {
      $(row).data("url", data["url"])
   }
});

and on click we use this data attribute for url:

table.on( 'click', 'tbody tr', function () {
  window.location.href = $(this).data("url");
} );

Answer 2

There is another method, which doesn't require exposing the entire url structure or ajax requests for resolving each url. While it's not really beautiful, it beats the others with simplicity:

var url = '{% url blog_view_post 999 %}'.replace (999, post_id);

(blog_view_post urls must not contain the magic 999 number themselves of course.)

Answer 3

I've found a simple trick for this. If your url is a pattern like:

"xyz/(?P<stuff>.*)$"

and you want to reverse in the JS without actually providing stuff (deferring to the JS run time to provide this) - you can do the following:

Alter the view to give the parameter a default value - of none, and handle that by responding with an error if its not set:

views.py

def xzy(stuff=None):
  if not stuff:
    raise Http404
  ... < rest of the view code> ...

• Alter the URL match to make the parameter optional: "xyz/(?P<stuff>.*)?$"

• And in the template js code:

  .ajax({ url: "{{ url views.xyz }}" + js_stuff, ... ... })

The generated template should then have the URL without the parameter in the JS, and in the JS you can simply concatenate on the parameter(s).