1、首先,我现在pugins文件夹下写一个自己的插件 复制PHP内容到剪贴板 PHP代码:
<?php /* Plugin Name: test Plugin URI: [url=http://wordpress.org/]http://wordpress.org/[/url]# Description: 我测试用的 Author: lw(fantasy) Version: 0.1 Author URI: [url=http://www.xxx.com/]http://www.xxx.com/[/url] */ $test = "<div id=''my_test''>这是我的第一个插件!</div>";
function output(){ global $test; echo $test; }
add_action(''wp_footer'',''output''); ?>
然后在后台启用。。
2、WP执行是加载在”wp-settings.php”,而在此文件中,可以找到以下与插件相关的代码片断: 复制PHP内容到剪贴板 PHP代码: if ( get_option(''active_plugins'') ) { $current_plugins = get_option(''active_plugins''); dump($current_plugins); if ( is_array($current_plugins) ) { foreach ($current_plugins as $plugin) { if ( '''' != $plugin && 0 == validate_file($plugin) && file_exists(WP_PLUGIN_DIR . ''/'' . $plugin) ) include_once(WP_PLUGIN_DIR . ''/'' . $plugin); } } }
我dump了一下$current_plugins,得到
Array ( [0] => Fanfou-Daily/Fanfou-Daily.php [1] => mulberrykit.php [2] => test.php )
可以看到我写的test.php插件已经被include进去了。。
3、在主题模板里的footer.php里面会执行一个函数 <?php wp_footer(); ?>
而这个wp_footer里面又执行
do_action(''wp_footer'');
而这个do_action就是执行前面我们已经注册了的【add_action(''wp_footer'',''output''); 】output()函数。。。
这样就输出了"<div id=''my_test''>这是我的第一个插件!</div>"了
最后贴一下do_action的源码,大家体会一下吧 复制PHP内容到剪贴板 PHP代码: /** * do_action() - Execute functions hooked on a specific action hook. * * This function invokes all functions attached to action hook <tt>$tag</tt>. * It is possible to create new action hooks by simply calling this function, * specifying the name of the new hook using the <tt>$tag</tt> parameter. * * You can pass extra arguments to the hooks, much like you can with apply_filters(). * * @see apply_filters() This function works similar with the exception that nothing is * returned and only the functions or methods are called. * * @package WordPress * @subpackage Plugin * @since 1.2 * @global array $wp_filter Stores all of the filters * @global array $wp_actions Increments the amount of times action was triggered. * * @param string $tag The name of the action to be executed. * @param mixed $arg,... Optional additional arguments which are passed on to the functions hooked to the action. * @return null Will return null if $tag does not exist in $wp_filter array */ function do_action($tag, $arg = '''') { global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter; if ( is_array($wp_actions) ) $wp_actions[] = $tag; else $wp_actions = array($tag); $wp_current_filter[] = $tag; // Do ''all'' actions first if ( isset($wp_filter[''all'']) ) { $all_args = func_get_args(); _wp_call_all_hook($all_args); } if ( |