Using require_once in a Plugin?

admin管理员组

文章数量:1406926

What's the difference between these two code snippets, and which one should I use for a WordPress plugin?

require_once(dirname(__FILE__).'/inc/canagan_admin_functions.php');
require_once( '/inc/canagan_admin_functions.php' );

What's the difference between these two code snippets, and which one should I use for a WordPress plugin?

require_once(dirname(__FILE__).'/inc/canagan_admin_functions.php');
require_once( '/inc/canagan_admin_functions.php' );

• plugins
• plugin-development
• php

Share Improve this question edited Nov 20, 2019 at 14:20 the 1,56822 gold badges1313 silver badges3232 bronze badges asked Nov 30, 2011 at 2:07 ShoeboxShoebox 33422 gold badges66 silver badges1515 bronze badges 1

• 1 The first one, because the second one won't work. – Otto Commented Nov 30, 2011 at 2:12

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 11

The first one is like saying...

Include the file found in the inc directory, above the directory where this file is located.

The second statement is saying...

in the server root (/) look in the inc folder for canagan_admin_functions.php and include it.

The first one will work, the second won't. In the second you're looking in the root of the entire file system, where you file certainly won't be.

As a side note, whenever I start a plugin that's going to span multiple files, and/or enqueues CSS or JS files, I usually set up a few constant to help me along the way. Here's an example.

<?php
define( 'CD_PLUGIN_PATH', plugin_dir_path( __FILE__ ) );
define( 'CD_PLUGIN_URL', plugin_dir_url( __FILE__ ) );

plugin_dir_path and plugin_dir_url are nice because they always return paths/urls with trailing slashes.

Then to include/require files, I use the constants. Keeps from having to call dirname(__FILE__) on every include.

You can then use the constants to include files...

require_once( CD_PLUGIN_PATH . 'path/to/file.php' );

or to enqueue scripts/styles...

<?php
add_action( 'wp_enqueue_scripts', 'wpse35088_enqueue' );
function wpse35088_enqueue()
{
    wp_enqueue_script( 'wpse35088-script', CD_PLUGIN_URL . 'path/to/script.js' );
}

本文标签： Using requireonce in a Plugin