admin_init
云策文档标注
概述
admin_init 是一个 WordPress 钩子，在管理屏幕或脚本初始化时触发。它类似于 init 钩子，但专门用于管理区域，包括 admin-ajax.php 和 admin-post.php。
关键要点
- admin_init 钩子在用户访问管理区域时，在其他钩子之前触发。
- 该钩子不提供任何参数，只能用于回调指定函数。
- 它适用于所有管理相关屏幕，包括 Ajax 和 POST 请求处理。
- 常用于注册插件设置、限制管理访问或执行其他管理端初始化任务。
代码示例
// 示例1：注册插件设置
function myplugin_settings() {
register_setting( 'myplugin', 'myplugin_setting_1', 'intval' );
register_setting( 'myplugin', 'myplugin_setting_2', 'intval' );
}
add_action( 'admin_init', 'myplugin_settings' );
// 示例2：限制非管理员访问管理屏幕（重定向）
function restrict_admin_with_redirect() {
if ( ! current_user_can( 'manage_options' ) && ( ! wp_doing_ajax() ) ) {
wp_safe_redirect( site_url() );
exit;
}
}
add_action( 'admin_init', 'restrict_admin_with_redirect', 1 );
// 示例3：限制非管理员访问管理屏幕（显示消息）
function restrict_admin() {
if ( ! current_user_can( 'manage_options' ) && ( ! wp_doing_ajax() ) ) {
wp_die( __( 'You are not allowed to access this part of the site' ) );
}
}
add_action( 'admin_init', 'restrict_admin', 1 );
// 示例4：在管理屏幕初始化时执行操作
function the_dramatist_fire_on_admin_screen_initialization() {
echo 'Hello World';
}
add_action( 'admin_init', 'the_dramatist_fire_on_admin_screen_initialization' );注意事项
- admin_init 钩子不仅运行在用户可见的管理屏幕，也运行在 admin-ajax.php 和 admin-post.php 脚本中。
- 使用此钩子时，需注意权限检查，以避免影响 Ajax 请求的正常功能。
- 钩子优先级可调整，例如示例中使用了优先级 1 来确保早期执行。
原文内容
Fires as an admin screen or script is being initialized.
Description
Note, this does not just run on user-facing admin screens.
It runs on admin-ajax.php and admin-post.php as well.
This is roughly analogous to the more general ‘init’ hook, which fires earlier.
Source
do_action( 'admin_init' );
Changelog
| Version | Description |
|---|---|
| 2.5.0 | Introduced. |
Skip to note 5 content
Steven Lin
Example migrated from Codex:
Another typical usage is to register a new setting for use by a plugin:
function myplugin_settings() { register_setting( 'myplugin', 'myplugin_setting_1', 'intval' ); register_setting( 'myplugin', 'myplugin_setting_2', 'intval' ); } add_action( 'admin_init', 'myplugin_settings' );Skip to note 6 content
Steven Lin
Example migrated from Codex:
This example works similarly to the first example, but it will automatically redirect users lacking the specified capability to the homepage.
/** * Restrict access to the administration screens. * * Only administrators will be allowed to access the admin screens, * all other users will be automatically redirected to the front of * the site instead. * * We do allow access for Ajax requests though, since these may be * initiated from the front end of the site by non-admin users. */ function restrict_admin_with_redirect() { if ( ! current_user_can( 'manage_options' ) && ( ! wp_doing_ajax() ) ) { wp_safe_redirect( site_url() ); exit; } } add_action( 'admin_init', 'restrict_admin_with_redirect', 1 );Skip to note 7 content
Steven Lin
Example migrated from Codex:
In this example, we block access to the admin panel for users that do not have the Administrator Role.
/** * Restrict access to the administration screens. * * Only administrators will be allowed to access the admin screens, * all other users will be shown a message instead. * * We do allow access for Ajax requests though, since these may be * initiated from the front end of the site by non-admin users. */ function restrict_admin() { if ( ! current_user_can( 'manage_options' ) && ( ! wp_doing_ajax() ) ) { wp_die( __( 'You are not allowed to access this part of the site' ) ); } } add_action( 'admin_init', 'restrict_admin', 1 );Skip to note 8 content
Rnaby
/** * Fire on the initialization of the admin screen or scripts. */ function the_dramatist_fire_on_admin_screen_initialization() { // Do stuff. Say we will echo "Hello World". echo 'Hello World'; } add_action( 'admin_init', 'the_dramatist_fire_on_admin_screen_initialization' );The above piece of code will only echo “Hello World” if the user is in admin screen.