get group directory to listen to GET requests like `/groups?type=forum`

[JonathanReeve]

This will allow us to have URLs associated with certain group directory tabs.

Alternatively, we could use hashes: /groups#forums. This might allow for better AJAX integration.

[chriszarate]

Let's stick with query strings, which are much less complicated than hashes and hash-bangs—especially when it comes to playing nice with Google et al. We can fill in gaps with the History API if we need to. Let's talk about overall strategy here.

[JonathanReeve]

What works:

• PHP listens to $_GET parameters, such that navigating cold to http://my-vm/groups/?type=committees correctly takes you to the committees page.
• JS sets the URL after filtering groups with AJAX, such that clicking "committees" changes the url to http://my-vm/groups/?type=committees.
• Clicking to anther page from Committees, and then clicking the browser "back" button changes the URL back to http://my-vm/groups/?type=committees.

What doesn't work yet:

• Although clicking "back" changes the URL, and although PHP can interpret those URLs when cold-visited, clicking "back" doesn't take you to the properly filtered page, so you can go back from, say, http://my-vm/groups/?type=forums to http://my-vm/groups?type=committees, but you won't see a list of committees.

[chriszarate]

You're pushing state into the History API, so you just need to listen for popstate. Something like this should work:

jq(window).on('popstate', function () {
  // do stuff with window.location.search
});