Django javascript url helper

0-url-helper.md

Pass the urls you care about to your javascript:

return {
  'urls': js_urls(
    'foo',   # 'foo' => r'^(?P<slug>[a-z0-9-]+)/'
    'bar',   # 'bar' => r'^bar/(?P<id>[0-9-]+)/'
  ),
}

Then in your javascript you can get the url by it's name:

import {reverse} from '.urls';

let url = reverse('foo', {'slug': 'buzz'}); // => /buzz/
let url2 = reverse('bar', {'id': 1}); // => /bar/1/

js_urls.py

from django.core.urlresolvers import get_resolver


def js_urls(*urls):
    """return a dict key being url name and value is the url pattern"""

    resolver = get_resolver(None)
    return {
        key: resolver.reverse_dict[key][0][0][0] for key in urls
    }

urls.js

import {urls} from 'ofs/payload';

export function reverse(name, values) {
  if (typeof urls[name] === 'undefined') {
    throw new Error(`No url called ${name}`);
  }

  let pattern = urls[name];
  return '/' + pattern.replace(/%\((.*?)\)s/g, (match, namedMatch) => {
    if (typeof values[namedMatch] === 'undefined') {
      throw new Error(`Url ${name} requires kwarg ${namedMatch}`);
    }
    return values[namedMatch];
  });
}