title: Django - How to pass dynamic models between pages
body: <p>I have made a django app that creates models and database tables on the fly. This is, as far as I can tell, the only viable way of doing what I need. The problem arises of how to pass a dynamically created model between pages. </p>
  
  <p>I can think of a few ways of doing such but they all sound horrible. The methods I can think of are:</p>
  
  <ol>
  <li>Use global variables within views.py. This seems like a horrible hack and likely to cause conflicts if there are multiple simultaneous users. </li>
  <li>Pass a reference in the URL and use some eval hackery to try and refind the model. This is probably stupid as the model could potentially be garbage collected en route. </li>
  <li>Use a place-holder app. This seems like a bad idea due to conflicts between multiple users.</li>
  <li>Having an invisible form that posts the model when a link is clicked. Again very hacky. </li>
  </ol>
  
  <p>Is there a good way of doing this, and if not, is one of these methods more viable than the others?</p>
  
  <p>P.S. In case it helps my app receives data (as a json string) from a pre-existing database, and then caches it locally (i.e. on the webserver) creating an appropriate model and table on the fly. The idea is then to present this data and do various filtering and drill downs on it with-out placing undue strain on the main database (as each query returns a few hundred results out of a database of hundreds of millions of data points.) W.R.T. 3, the tables are named based on a hash of the query and time stamp, however a place-holder app would have a predetermined name. </p>
  
  <p>Thanks,</p>
  
  <p>jhoyla</p>
  
  <p>EDITED TO ADD: Thanks guys, I have now solved this problem. I ended up using both answers together to give a complete answer. As I can only accept one I am going to accept the contenttypes one, sadly I don't have the reputation to give upvotes yet, however if/when I ever do I will endeavor to return and upvote appropriately.</p>
  
  <p>The solution in it's totality, </p>
  
  <pre><code>from django.contrib.contenttypes.models import ContentType
  view_a(request):
      model = create_model(...)
      request.session['model'] =  ContentType.objects.get_for_model(model)
      ...
  
  view_b(request):
      ctmodel = request.session.get('model', None)
      if not ctmodel:
          return Http404
      model = ctmodel.model_class()
      ...
  </code></pre>