Determining Plugin and Content Directories

When coding WordPress plugins you often need to reference various files and folders throughout the WordPress installation and within your plugin or theme.

WordPress provides several functions for easily determining where a given file or directory lives. Always use these functions in your plugins instead of hard-coding references to the wp-content directory or using the WordPress internal constants.

[tip]WordPress allows users to place their wp-content directory anywhere they want and rename it whatever they want. Never assume that plugins will be in wp-content/plugins, uploads will be in wp-content/uploads, or that themes will be in wp-content/themes.[/tip]

PHP's __FILE__ magic-constant resolves symlinks automatically, so if the wp-content/ or wp-content/plugins/ or even the individual plugin directory is symlinked, hardcoded paths will not work correctly.

Common Usage

If your plugin includes JavaScript files, CSS files or other external files, then it's likely you'll need the URL to these files so you can load them into the page. To do this you should use the plugins_url() function like so:

plugins_url( 'myscript.js', __FILE__ );

This will return the full URL to myscript.js, such as example.com/wp-content/plugins/myplugin/myscript.js.

To load your plugins' JavaScript or CSS into the page you should use wp_enqueue_script() or wp_enqueue_style() respectively, passing the result of plugins_url() as the file URL.

Available Functions

WordPress includes many other functions for determining paths and URLs to files or directories within plugins, themes, and WordPress itself. See the individual DevHub pages for each function for complete information on their use.

Plugins

• plugins_url()
• plugin_dir_url()
• plugin_dir_path()
• plugin_basename()

Themes

• get_template_directory_uri()
• get_stylesheet_directory_uri()
• get_stylesheet_uri()
• get_theme_root_uri()
• get_theme_root()
• get_theme_roots()
• get_stylesheet_directory()
• get_template_directory()

Site Home

• home_url()
• get_home_path()

WordPress

• admin_url()
• site_url()
• content_url()
• includes_url()
• wp_upload_dir()

Multisite

• get_admin_url()
• get_home_url()
• get_site_url()
• network_admin_url()
• network_site_url()
• network_home_url()

Constants

WordPress makes use of the following constants when determining the path to the content and plugin directories. These should not be used directly by plugins or themes, but are listed here for completeness.

WP_CONTENT_DIR  // no trailing slash, full paths only
WP_CONTENT_URL  // full url 
WP_PLUGIN_DIR  // full path, no trailing slash
WP_PLUGIN_URL  // full url, no trailing slash

// Available per default in MS, not set in single site install
// Can be used in single site installs (as usual: at your own risk)
UPLOADS // (If set, uploads folder, relative to ABSPATH) (for e.g.: /wp-content/uploads)

Related

WordPress Directories