code: def update_angular_template_hash(sender, **kwargs):
      
      context = kwargs['context']  # context the compressor is working with
      compressed = context['compressed']  # the compressed content
      compressed_name = compressed['name']  # name of the compressed content
      if compressed_name == 'angular_template_cache_preloads':
          # The compressor has modified the angular template cache preloads
          # which are cached in the 'default' Django cache. Fetch that cache.
          cache = caches['default']
  
          # generate the same key as used in _scripts.html when caching the
          # preloads
          theme = context['THEME']  # current theme being compressed
          key = make_template_fragment_key(
              "angular",
              ['template_cache_preloads', theme]
          )
  
          # if template preloads have been cached, clear them
          if cache.get(key):
              cache.delete(key)
docs: Listen for compress events.
  
      If the angular templates have been re-compressed, also clear them
      from the Django cache backend.  This is important to allow
      deployers to change a template file, re-compress, and not
      accidentally serve the old Django cached version of that content
      to clients.