ci + jquery

[eluser]onejaguar[/eluser]
Personally I do everything back and forth with JSON which ends up being a lot more flexible.

Here is the CodeIgniter Controller:

Code:

class Ajax extends Controller {

  var $json_data=Array(
    'error' => 1,
    'html' => 'Ajax Error: Invalid Request'
    );

  function __construct() {
    parent::Controller();
    $this->output->set_header('Last-Modified: '.gmdate('D, d M Y H:i:s', time()).' GMT');
    $this->output->set_header('Expires: '.gmdate('D, d M Y H:i:s', time()).' GMT');
    $this->output->set_header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0");
    $this->output->set_header("Pragma: no-cache");
  }

  function do_something() {
    $this->json_data['html'] = $this->load->view('someview', $_POST, true);
    $this->json_data['error'] = 0;
    $this->json_data['another_variable'] = 42;
  }

  function _output($output) {
    echo json_encode($this->json_data);
  }
}

Then in the script...

Code:

$.ajax({
    url: '/ajax/do_something/',
    type: 'POST',
    data: {field: value},
    dataType: 'json',
    timeout: 8000,
    success: success_function
  });

  function success_function(json) {
    if (json.error)
      alert(json.html);
    else
      $('#result_div').html(json.html);

    if (json.another_variable == 42)
      alert("I've found the secret of life!");
  }

Obviously much more useful data can be passed back and forth. Everything in the 'data' object on the Javascript side will be in $_POST in CodeIgniter. I have used this setup for two sites now; one with a single AJAX controller that acts as router redirecting to mini-modules; another which uses several controllers just for ajax calls. If you are doing the latter you could setup a parent AJAX controller object which gets extended by all your AJAX controllers.