why quotes shown in Wordpress?

Question

I have written a function to register a script in the admin interface.

function custom_admin_js() {
    $url = get_bloginfo('template_directory') . '/admin/admin.js';
    echo '<script type="text/javascript" src="'. $url . '"></script>';
}
add_action('admin_footer', 'custom_admin_js');

For some - for me unknown reason - this creates additional quotes surrounding the script.

"<script type="text/javascript" src="http://test121.uphero.com/wp-content/themes/news/admin/admin.js"></script>"

How do I remove the surrounding quotes?

Answer 1

I am not sure about the extra quotes. The best way to include a java script file is with wp_enqueue_script() as indicated here in the codex.

The safe and recommended method of adding JavaScript to a WordPress generated page and WordPress Theme or Plugin is by using wp_enqueue_script(). This function includes the script if it hasn't already been included, and safely handles dependencies.

add_action( 'admin_enqueue_scripts', 'wpse8170_enqueue_scripts' );
function wpse8170_enqueue_scripts() {
    wp_enqueue_script( 'wpse8170-admin-js', get_template_directory_uri() . '/admin/admin.js', null, null, true );
}

When in doubt use the function designed to do what you want to do. Reinventing the wheel almost always creates new problems.