I'm trying to make my first plugin, but when I try wp_enqueue_script the script file, I get errors about the ID, post_title, post_name, even though its a single page (i.e. not posts kind of page).

// enqueue scripts
function myplugin_enqueue_scripts( $hook ) {
    if ( !is_page('my-page'))  { return; }

    // define script url
    $script_url = plugins_url( 'public/myplugin.js', __FILE__ );

    // enqueue script
    // Below line cause the error
    wp_enqueue_script('myplugin', $script_url);

}
add_action( 'wp_enqueue_scripts', 'myplugin_enqueue_scripts', 1);

I get this error message:

[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'ID' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3994
[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'post_title' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3996
[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'post_name' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3998

Within myplugin.js is one line:

console.log("Please work");

I also tried the template_redirect hook but no difference. Why is this error being generated?

I'm trying to make my first plugin, but when I try wp_enqueue_script the script file, I get errors about the ID, post_title, post_name, even though its a single page (i.e. not posts kind of page).

// enqueue scripts
function myplugin_enqueue_scripts( $hook ) {
    if ( !is_page('my-page'))  { return; }

    // define script url
    $script_url = plugins_url( 'public/myplugin.js', __FILE__ );

    // enqueue script
    // Below line cause the error
    wp_enqueue_script('myplugin', $script_url);

}
add_action( 'wp_enqueue_scripts', 'myplugin_enqueue_scripts', 1);

I get this error message:

[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'ID' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3994
[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'post_title' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3996
[23-Jun-2020 21:59:56 UTC] PHP Notice:  Trying to get property 'post_name' of non-object in /usr/www/users/sexerxm/example.server/wp-includes/class-wp-query.php on line 3998

Within myplugin.js is one line:

console.log("Please work");

I also tried the template_redirect hook but no difference. Why is this error being generated?

• wp-enqueue-script

• Are you trying this on a clean installation? Does the error persist if you try a regular string as the URL instead of the plugins_url function result? – Himad Commented Jun 23, 2020 at 22:23
• Additionally its not a clean installation, the person has a woo commerce plugin installed and a few others. I am not sure i am allowed to disable them. I tried a high and low add_action priority to try negate other plugin interference but jad the same result – run_the_race Commented Jun 24, 2020 at 6:49

1 Answer 1

Issue 1

I was not seeing the embedded object in javascript because:

The error was, I thought plugins_url always resolved to the plugins dir, it resolves to the dir of __FILE__:

In my situation myplugin.js and myplugin.php are both in the same public/ dir, so this:

$script_url = plugins_url( 'public/myplugin.js', __FILE__ )

Was resolving as (notice the double public):

http://server.example/wp-content/plugins/myplugin/public/public/myplugin.js

instead of

http://server.example/wp-content/plugins/myplugin/public/myplugin.js

Issue 2

I still see the error, however even with my plugin disabled, and managed to track it down to WooComerce by looking at the debug network tab and seeing the ajax request.