I need to add some data to the user's meta on my website. To do so, I use ajax to call a PHP file on my server, however, when the code is executed, it just returns null instead of the user class. Here is the JS code:

<script>
    jQuery.ajax({
    type: "POST",
    url: 'https://mywebsite.com/wp-content/ajax/file.php',
    dataType: 'json',
    data: {},

    success: function (obj, textstatus) {
                      console.log(obj);
            }
});
</script>

And the contents of file.php are:

<?php
    header('Content-Type: application/json');
    global $current_user;
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);
    // 3 llines above are just to display the error if any
    get_currentuserinfo();
    echo json_encode($current_user->ID);
?>

When I execute this, the error says that Uncaught Error: Call to undefined function get_currentuserinfo() in...

When I delete this line, the output is just null. I don't know If I'm doing everything correctly, but feel free to suggest different solutions. I do not need the ID to be returned, but the $current_user variable should not be empty.

CodePudding user response：

There's no reason to include a whole separate .php file to handle AJAX requests. What's happening is that because you're including your own custom file, you're including it outside of the WordPress environment, so you don't have access to WordPress variables and functions.

You have two options:

1. Use the built in AJAX methods, actions, and handlers

2. "Include" WordPress in your custom .php file

Of course, I'd recommend you go with the first method. It's (almost) as simple as using the wp_ajax_{$action} hook, and posting the request to admin-ajax.php instead of your file.

jQuery.post(
    ajax_object.ajax_url,
    {action: 'my_action'},
    function( response ){
        alert( 'Here is the response: '   response );
    }
);

and in your functions.php (or similar) file:

// Wherever you are enqueing this JS file, use `wp_localize_script` to pass variables to it
wp_enqueue_script( 'your-script', $link_to_your_js, array('jquery') );
wp_localize_script( 'your-script', 'ajax_object', array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) );

and then

add_action( 'wp_ajax_my_action', 'my_action_function' );
my_action_function(){
    $user_info = get_currentuserinfo();
    wp_send_json( $user_info );
}

Alternatively - and less appropriately - you can include wp-load.php into your file.php, using one of the many answers on how to "include wp-load.php" in a file.

A last note, using wp_localize_script you can actually pass the current user's information directly to the script, so you don't need to make an AJAX request for it:

wp_localize_script( 'your-script', 'ajax_object', array(
    'ajax_url' => admin_url( 'admin-ajax.php' ),
    'current_userinfo' => get_currentuserinfo()
);

^ at which point the your-script JS file would have access to current_userinfo.ID and all the other variables available to it directly.