AJAX调用期间是否曾经调用过functions.php文件？调试AJAX

admin-ajax.php加载wp-load.php:

 /** Load WordPress Bootstrap */
require_once( dirname( dirname( __FILE__ ) ) . '/wp-load.php' );
 

wp-load.php会加载wp-config.php,然后会加载wp-settings.php.

在这里我们找到这个:

 // Load the functions for the active theme, for both parent and child theme if applicable.
if ( ! defined( 'WP_INSTALLING' ) || 'wp-activate.php' === $pagenow ) {
    if ( TEMPLATEPATH !== STYLESHEETPATH && file_exists( STYLESHEETPATH . '/functions.php' ) )
        include( STYLESHEETPATH . '/functions.php' );
    if ( file_exists( TEMPLATEPATH . '/functions.php' ) )
        include( TEMPLATEPATH . '/functions.php' );
}
 

所以,是的,主题的functions.php已加载.

wp-settings.php中有一个例外:

 // Stop most of WordPress from being loaded if we just want the basics.
if ( SHORTINIT )
    return false;
 

如果先前将SHORTINIT定义为TRUE,则不会加载主题.

因此请出于某种原因检查SHORTINIT是否为TRUE.

另一个常见错误是is_admin()的错误使用.在admin-ajax.php中始终为TRUE,因此以下操作将失败:

 if ( ! is_admin() )
    // register or execute AJAX stuff
 

调试AJAX

一种有效的原始方法是使用HTTP标头调试AJAX.

这是一个简单的辅助函数:

 function send_debug_header( $msg )
{
    static $counter = 1;
    header( "X-Debug-Ajax-$counter: $msg" );
    $counter += 1;
}
 

此插件显示了如何使用它:

 <?php # -*- coding: utf-8 -*-
/**
 * Plugin Name: Debug AJAX per HTTP
 * Description: Look at the HTTP headers in your browser's network console
 */

// The constant is already defined when plugins are loaded.
// Prove we have been called.
if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
    send_debug_header( 'File "' . __FILE__ . '" was called on an AJAX request.' );

function send_debug_header( $msg )
{
    static $counter = 1;
    header( "X-Debug-Ajax-$counter: $msg" );
    $counter += 1;
}

add_action( 'wp_ajax_debug_test',        't5_debug_test' );
add_action( 'wp_ajax_nopriv_debug_test', 't5_debug_test' );

function t5_debug_test()
{
    $in = is_user_logged_in() ? '' : 'not ';
    send_debug_header( 'Function "' . __FUNCTION__ . '" was called and the user is ' . $in . 'logged in.' );
    print_r( debug_backtrace() );
    die(1);
}

add_action( 'wp_enqueue_scripts', 't5_enqueue_jquery' );

function t5_enqueue_jquery()
{
    wp_enqueue_script( 'jquery' );
}
add_action( 'wp_footer', 't5_debug_ajax_test_button', 0 );

function t5_debug_ajax_test_button()
{
    ?>
<input type="submit" id="t5debugajax" value="Debug AJAX">
<script>
jQuery( function($){
    var sendFeedBack = function( response ){
        console.log( response );
    };
    $("#t5debugajax").on("click", function(){
        $.post(
            "<?php echo admin_url( 'admin-ajax.php' ); ?>",
            {
                action: "debug_test"
            },
            sendFeedBack
        );
    });
});
</script>
    <?php
}
 

它将在前端添加一个按钮,单击该按钮会触发AJAX请求.打开浏览器的网络控制台,然后查看请求的响应标头:

admin-ajax.php loads wp-load.php:

/** Load WordPress Bootstrap */
require_once( dirname( dirname( __FILE__ ) ) . '/wp-load.php' );

wp-load.php loads wp-config.php, and there wp-settings.php is loaded.

And here we find this:

// Load the functions for the active theme, for both parent and child theme if applicable.
if ( ! defined( 'WP_INSTALLING' ) || 'wp-activate.php' === $pagenow ) {
    if ( TEMPLATEPATH !== STYLESHEETPATH && file_exists( STYLESHEETPATH . '/functions.php' ) )
        include( STYLESHEETPATH . '/functions.php' );
    if ( file_exists( TEMPLATEPATH . '/functions.php' ) )
        include( TEMPLATEPATH . '/functions.php' );
}

So, yes, the theme’s functions.php is loaded.

There is one exception in wp-settings.php:

// Stop most of WordPress from being loaded if we just want the basics.
if ( SHORTINIT )
    return false;

When SHORTINIT is defined as TRUE earlier, the theme will not be loaded.

So check if SHORTINIT is TRUE for some reason.

Another common error is the wrong usage of is_admin(). This is always TRUE in admin-ajax.php, so the following will fail:

if ( ! is_admin() )
    // register or execute AJAX stuff

Debugging AJAX

One method as primitive as efficient is using HTTP header to debug AJAX.

Here is a simple helper function:

function send_debug_header( $msg )
{
    static $counter = 1;
    header( "X-Debug-Ajax-$counter: $msg" );
    $counter += 1;
}

And this plugin shows how to use it:

<?php # -*- coding: utf-8 -*-
/**
 * Plugin Name: Debug AJAX per HTTP
 * Description: Look at the HTTP headers in your browser's network console
 */

// The constant is already defined when plugins are loaded.
// Prove we have been called.
if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
    send_debug_header( 'File "' . __FILE__ . '" was called on an AJAX request.' );

function send_debug_header( $msg )
{
    static $counter = 1;
    header( "X-Debug-Ajax-$counter: $msg" );
    $counter += 1;
}

add_action( 'wp_ajax_debug_test',        't5_debug_test' );
add_action( 'wp_ajax_nopriv_debug_test', 't5_debug_test' );

function t5_debug_test()
{
    $in = is_user_logged_in() ? '' : 'not ';
    send_debug_header( 'Function "' . __FUNCTION__ . '" was called and the user is ' . $in . 'logged in.' );
    print_r( debug_backtrace() );
    die(1);
}

add_action( 'wp_enqueue_scripts', 't5_enqueue_jquery' );

function t5_enqueue_jquery()
{
    wp_enqueue_script( 'jquery' );
}
add_action( 'wp_footer', 't5_debug_ajax_test_button', 0 );

function t5_debug_ajax_test_button()
{
    ?>
<input type="submit" id="t5debugajax" value="Debug AJAX">
<script>
jQuery( function($){
    var sendFeedBack = function( response ){
        console.log( response );
    };
    $("#t5debugajax").on("click", function(){
        $.post(
            "<?php echo admin_url( 'admin-ajax.php' ); ?>",
            {
                action: "debug_test"
            },
            sendFeedBack
        );
    });
});
</script>
    <?php
}

It will add a button to the front end that triggers an AJAX request when clicked. The open your browser’s network console and look at the response headers for the request:

我认为如果您的帐户已登录而AJAX仍在工作,而未处于注销状态,对吗?
WordPress中有一个功能可以为未登录的用户访问基于AJAX的文件:例如,wp_ajax_nopriv

 /* works for logged users */
add_action( 'wp_ajax_my_action', 'my_action_callback');

/* works for non logged users */
add_action( 'wp_ajax_nopriv_my_action', 'my_action_callback');
 

I assume your problem was AJAX was working if your are logged in and it was not working in logged out status, right?
There is a function in WordPress to access AJAX-based files for non logged users: wp_ajax_nopriv, for example

/* works for logged users */
add_action( 'wp_ajax_my_action', 'my_action_callback');

/* works for non logged users */
add_action( 'wp_ajax_nopriv_my_action', 'my_action_callback');