What is the constant WP_USE_THEMES for?

This is only used in template-loader.php, to determine whether it should load a theme file or not. The normal “boot sequence” of WordPress (started in wp-blog-header.php) loads the plugins, parses the URL, executes a post query based on the URL, and calls the theme. This main post query is typically used in “The Loop”. So … Read more

How do I get the theme URL in PHP?

This function will return the theme directory URL so you can use it in other functions: get_bloginfo(‘template_directory’); Alternatively, this function will echo the theme directory URL to the browser: bloginfo(‘template_directory’); So an example for an image in the themes images/headers folder would be: <img src=”https://wordpress.stackexchange.com/questions/665/<?php bloginfo(“template_directory’); ?>/images/headers/image.jpg” />

What is the preferred way to add custom javascript files to the site?

Use wp_enqueue_script() in your theme The basic answer is to use wp_enqueue_script() in an wp_enqueue_scripts hook for front end admin_enqueue_scripts for admin. It might look something like this (which assumes you are calling from your theme’s functions.php file; note how I reference the stylesheet directory): <?php add_action( ‘wp_enqueue_scripts’, ‘mysite_enqueue’ ); function mysite_enqueue() { $ss_url = … Read more