Distant parent + Dependent Views filters with AJAX

OK, the principle here seems to work, and can be easily applied to the Cities.

  // COUNTRY
  $selected_country = $form['filter2']['#default_value']; // get the selected country cid
  // END COUNTRY

  // STATE/PROVINCE
  $options = $form['filter3']['#options']; // array of states/provinces

  // ... code to remove options you don't want ...
  foreach ($options as $option => $text) {
    $parents = category_get_parents($option, 'cid', true);
    $parent = $parents[0]->cid;
    if ($parent != $selected_country) { // state/province parent doesn't match the selected country
      unset($options[$option]); // remove it from the list
    }
  }
  $form['filter3']['#options'] = $options;

  // don't display the states/provinces filter if there are no results
  if (empty($form['filter3']['#options'])) {
  	drupal_set_message('unset filster3');
  	unset($form['filter3']);
  }
  // END STATE/PROVINCE

Can anyone help me with jQuery to make this all dynamic, so when I select a country, the state/province box appears and gets populated?

OK, got all of this working with Ajax. It's too complex to try to explain, so I will just attach a screenshot to this post and instructions on how to set it up to the next.

What this does (see screenshot):
* Use Active Select and to create Dependent Drop-downs from Views' Exposed Filters based on Distant Parent relationships, so when someone clicks on a country, the list of states/provinces in populated, etc.
* Counts how many nodes there are in each category and put the number there.
* Counts dependent of the classified type (left column), so when someone selects "For sale", the country/state/city lists only count the nodes for that type.

This is truly an amazing feature to have, as it integrates the wonderful ajax Category's distant-parent dependent drop-downs on the input of a node and (the all-powerful) Views for output. IMO this should be integrated into the category module, as it will open up amazing possibilities for output listing, but I see that it will be quite complicated to do that. All the pieces are there, so if the developers are interested, this is a good starting point.

Best,
Andrey.

Attached are all the instructions on how to get this going. It includes:
* small patch for category.module
* styles.css additions for general UI
* template.php functions
* custom filter template that is called from template.php - views_classifieds.tpl.php
* view setup instructions

note: I'm using Vim and have folds set up that get triggered by //{ and //}, so if you too are using Vim, adding those fold triggers will make it much more readable and organized, otherwise just ignore them.

This is solid and works great, it also degrades gracefully to a non-javascript/activeselect version. I'm planning to port this to an Event Calendar view as well for local events, as there isn't really anything now that supports nice browsing through local events. Eventually I will add Group functionality to the Event view interface.

Good luck!
Andrey.

Updated template.php functions, fixes.

I have too many projects going on at the moment, so I don't think I'll be making a module of this anytime soon.

Sorry.

It is stable, however, and we've used this on a production community site (transformationteam.net).

Andrey.

It might need a bit of tweaking to get Drupal 6 to work, try it out. It's been a while since I wrote this thing, and right now I'm not planning on any further development.

In our case, we are using it as an events/classified setup, and the site is closed membership, so we know the user's location before they join. We then create the appropriate city/state/country categories for them before we approve their application. People can then tag posts with the proper categories using the default category interface.

Hope this helps,
Andrey.