plugins_url() works everywhere but wp_reqister_script()

Question

So I should probably mention up front that I'm developing a plugin so my url is 'mysite.com/plugin' (Just in case this is related to my issue.

So, In my main plugin file (myplugin.php) I have added the following:

$plugin_url = plugins_url('/my-plugin-directory/');

immediately followed by

wp_enqueue_style('wp_enqueue_scripts', $plugin_url . 'css/boxes.css');

Great, so far so good. The plugin url is properly concatenated and the script is added to the page and appears in the source as

<link rel='stylesheet' id='wp_enqueue_scripts-css'  href='http://mysite.com/plugin/wp-content/plugins/my-plugin-directory/css/mystyle.css?ver=3.5.1' type='text/css' media='all' />

at this point I can even echo $plugin_url; which returns:

http://mysite.com/plugin/wp-content/plugins/my-plugin-directory/ 

Directly below that I have written the following function:

add_action("wp_enqueue_scripts", "my_jquery_enqueue", 11);
    function my_jquery_enqueue()    {
        wp_enqueue_script('jquery');
        wp_register_script('jquery_masonry', $plugin_url.'js/jquery.masonry.min.js', array('jquery'), '2.0.110526' );
        wp_enqueue_script('jquery_masonry');
    }

Should work right? It doesn't. Instead, in the source it looks like this:

<script type='text/javascript' src='http://georgespake.com/pluginjs/jquery.masonry.min.js?ver=2.0.110526'></script>

Boooo...

So for the time being, I just wrote it out:

/****Add jquery stuff to header****/
add_action("wp_enqueue_scripts", "my_jquery_enqueue", 11);
    function my_jquery_enqueue()    {
        wp_enqueue_script('jquery');
        wp_register_script('jquery_masonry', $plugin_url . '/wp-content/plugins/my-plugin-directory/js/jquery.masonry.min.js', array('jquery'), '2.0.110526' );
        wp_enqueue_script('jquery_masonry');
    }

This feels sloppy though because this is the only place I have to do this. Everywhere else, the $plugin_url seems to return the proper string. What am I missing here?

Answer 1

This is a PHP issue, not specific to WordPress. I suggest reading the PHP documentation on variable scope to understand why this doesn't work.

There is no $plugin_url variable defined within the scope of your my_jquery_enqueue function, you would have to call global $plugin_url; first within the function to access it, though I don't suggest using something as generic as $plugin_url.

Personally I would create a class for the plugin to encapsulate everything and not pollute the global scope.