Koala Framework uses the ExtJS Connection class for all ajax request. Read that documentation for the basics.

Koala Framework adds a few request options on top of that:

Error Handling

When a request fails a error message will be displayed, in debug mode this will also contain debug information and give the user the possibility to resend the request.

Progress Bar

For more time consuming actions you can show a progress bar that will automatically update from the server side.

    timeout: 10*60*1000, //10min
    url: '/example/json-foo',
    progress: true

And in the Php Action:

public function jsonFooAction()
    $progressBar = new Zend_ProgressBar(
        new Kwf_Util_ProgressBar_Adapter_Cache($this->_getParam('progressNum')),
            0,  //min
            10  //max
    for($i=0; $i<10; $i++) {
        $progressBar->next(1, trl('doing nothing...'));