Question

Is there a clean, easy way to throw php exceptions through a json response jquery/ajax call.

Answer 1

You could do something like this in PHP (assuming this gets called via AJAX):

<?php

try {
    if (some_bad_condition) {
        throw new Exception('Test error', 123);
    }
    echo json_encode(array(
        'result' => 'vanilla!',
    ));
} catch (Exception $e) {
    echo json_encode(array(
        'error' => array(
            'msg' => $e->getMessage(),
            'code' => $e->getCode(),
        ),
    ));
}

In JavaScript:

$.ajax({
    // ...
    success: function(data) {
        if (data.error) {
            // handle the error
            throw data.error.msg;
        }
        alert(data.result);
    }
});

You can also trigger the error: handler of $.ajax() by returning a 400 (for example) header:

header('HTTP/1.0 400 Bad error');

Or use Status: if you’re on FastCGI. Note that the error: handler doesn’t receive the error details; to accomplish that you have to override how $.ajax() works 🙂