Can one hook in wp_head inside other hook?

Question

I have to add some scripts in the head part of our website whenever a login or registration of a user was successful. For the login and register forms we use the Ultimate Member plugin, which has a hook method um_user_login and um_user_register which I though I could use for that.

I.e. if a user login was successful, do an head.append(...) in JavaScript.

However I am a NodeJS and Java developer and completely new to Wordpress plugin programming. I can't find a suitable solution so far for this easy sounding task.

My idea was to hook at the um_user_login action and do something like:

add_action('um_user_login', 'add_tracking_after_login', 10);

function add_tracking_after_login() {
    add_action('wp_head', function() {
        echo '<script type="text/javascript" src="my_script.js"></script>';
    });
}

However, I have tested this with different logging, but it seems like the hook function to wp_head is never executed (the function add_tracking_after_login is, as I have tested this with logging as well). So I think, I cannot add an action to wp_head this way.

Is there any other way to achieve the requested functionality? Or am I doing the hooking wrong as I am new to WordPress plugin programming?

Edit: To keep confusion low, this is just one of several tasks the client has requested. I also need to react on successful registrations and on successful sent emails with our contact form. In these cases I can't find an analogous workaround as in the answer below of Harry SM. I need to react on success events of the plugins we use.

Thanks in advance and best regards

score 2 · Accepted Answer · answered Jan 29 '18 at 14:57

2

you can add a condition for logged in user under wp_head hook.

add_action('wp_head', 'add_tracking_after_login', 10);

function add_tracking_after_login() {
    if ( is_user_logged_in() ) {
        echo '<script type="text/javascript" src="my_script.js"></script>';
    }
}

answered Jan 29 '18 at 14:57

Harry SM

76
5

Thanks, this should work in this case. Sadly this is the easiest of the tasks the client wants to have. I also need to react to wether the user registration was successful as well as wether an email was successfully sent via the "Contact us" - form. In those cases this workaround won't help. I gonna update my question. – Vegaaaa Jan 29 '18 at 15:13

score 0 · Answer 2 · answered Jan 29 '18 at 16:01

0

try this code for your plugin hook

add_action('um_user_login', 'add_tracking_after_login', 10); 
function add_tracking_after_login() { 
    wp_enqueue_script( 'custom-script', get_stylesheet_directory_uri() . '/js/custom_script.js', array( 'jquery' ) ); 
}

answered Jan 29 '18 at 16:01

Harry SM

76
5

Just to be sure, because I have the feeling, that something is broken due to another plugin: If I am using the js-file **only** in this single case, so I have never added it to the html head, did a `wp_register_script` etc., then the code you posted should work? I have tried the same but somehow the script is never invoked whereas when I am invoking the same snippet with `add_action('wp_head',...)` it is. This cannot be... – Vegaaaa Jan 29 '18 at 16:35

Can one hook in wp_head inside other hook?

2 Answers2