Returning JSON data with ajax in wordpress

Question

Ok so a fairly long question here. I\'m fairly new to AJAX and especially using it in the context of WordPress, but I\'ve been following along some tutorials online and I th

Answer 1

In your code get_posts('numberposts='.'&category=20'.$count); is wrong, but you can use wp_get_recent_posts function instead (though it uses get_posts anyway), for example

function ajax_get_latest_posts($count)
{
    $args = array( 'numberposts' => $count, 'order' => 'DESC','category' => 20 );
    $post = wp_get_recent_posts( $args );
    if( count($post) ) {
        return $post;
    }
    return false;
}

Then in your our_ajax-function you can use

    $output = ajax_get_latest_posts($_REQUEST['count']); // or $_GET['count']
    if($output) {
        echo json_encode(array('success' => true, 'result' => $output));
    }
    else {
        wp_send_json_error(); // {"success":false}
        // Similar to, echo json_encode(array("success" => false));
        // or you can use, something like -
        // echo json_encode(array('success' => false, 'message' => 'Not found!'));
    }

In you success callback function, you can then check

success:function(data){
    if(data.success) {
        // loop the array, and do whatever you want to do
        $.each(data.result, function(key, value){
            // you can use $(this) too
            // console.log($(this)); // check this for debug and get an idea
        });
    }
    else {
        // alert(data.message); // or whatever...
    }
}

You can read here about wp_send_json_error helper function to learn more about helper functions.

Update :

Also remember that, after $output=json_encode($output); the $output is not an array anymore, instead, it's a json string, so is_array($output) will return false but if you use is_array() just before you encode it using $output=json_encode($output); like

if( is_array( $output ) ) {
    $output = json_encode( $output );
}

In this case, is_array( $output ) will return true.

An example/simulation.