ajaxurl no definido en la interfaz

Enelbackend hay una variableglobal ajaxurl definidaporelpropio WordPress.

Esta variablenoes creadapor WPen lainterfaz. Significa que si desea utilizar llamadas AJAXen lainterfaz,debe definir dicha variable ustedmismo.

Unabuenaforma de hacerloes utilizar wp_localize_script.

Supongamos que sus llamadas AJAXestánen el archivo my-ajax-script.js,luego agregue wp_localize_scriptparaeste archivo JS así:

 function my_enqueue() {

    wp_enqueue_script( 'ajax-script', get_template_directory_uri() . '/js/my-ajax-script.js', array('jquery') );

    wp_localize_script( 'ajax-script', 'my_ajax_object',
            array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) );
}
add_action( 'wp_enqueue_scripts', 'my_enqueue' );
 

Después de localizar su archivo JS,puede usarel objeto my_ajax_objecten su archivo JS:

 jQuery.ajax(
    {
        type: "post",
        dataType: "json",
        url: my_ajax_object.ajax_url,
        data: formData,
        success: function(msg){
            console.log(msg);
        }
    });
 

In backend there is global ajaxurl variable defined by WordPress itself.

This variable is not created by WP in frontend. It means that if you want to use AJAX calls in frontend, then you have to define such variable by yourself.

Good way to do this is to use wp_localize_script.

Let's assume your AJAX calls are in my-ajax-script.js file, then add wp_localize_script for this JS file like so:

function my_enqueue() {

    wp_enqueue_script( 'ajax-script', get_template_directory_uri() . '/js/my-ajax-script.js', array('jquery') );

    wp_localize_script( 'ajax-script', 'my_ajax_object',
            array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) );
}
add_action( 'wp_enqueue_scripts', 'my_enqueue' );

After localizing your JS file, you can use my_ajax_object object in your JS file:

jQuery.ajax(
    {
        type: "post",
        dataType: "json",
        url: my_ajax_object.ajax_url,
        data: formData,
        success: function(msg){
            console.log(msg);
        }
    });

para usar ajaxurl directamente,en su archivo de complemento agregueesto:

 add_action('wp_head', 'myplugin_ajaxurl');

function myplugin_ajaxurl() {

   echo '<script type="text/javascript">
           var ajaxurl = "' . admin_url('admin-ajax.php') . '";
         </script>';
}
 

luegopuede usarel ajaxurlpara la solicitud ajax.

to use ajaxurl directly, in your plugin file add this:

add_action('wp_head', 'myplugin_ajaxurl');

function myplugin_ajaxurl() {

   echo '<script type="text/javascript">
           var ajaxurl = "' . admin_url('admin-ajax.php') . '";
         </script>';
}

you can then use the ajaxurl for ajax request.

He utilizadoel siguiente códigoen el sitio de WordPress.
podemos usarel siguiente códigopara configurar ajaxurl comoeste.

 <?php echo esc_url(admin_url('admin-ajax.php')); ?>  
 

También agregué unejemplo de ajax dondepodemos usar la línea anterior.

  function setNotificationRead() {
        fetch('<?php echo esc_url(admin_url('admin-ajax.php')); ?>', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded; charset=utf-8'
            },
            body: `action=yourFunctionsAction`,
            credentials: 'same-origin'
        }).then(response => {
            return response.json();
        }).then(data => {
            if (data.status === 'true') {
                console.log('Do something...');
            }
        });
    }
 

i have use below code in wordpress site.
we can use below code for setup ajaxurl like this.

<?php echo esc_url(admin_url('admin-ajax.php')); ?>  

i have also added ajax example were we can use above line.

 function setNotificationRead() {
        fetch('<?php echo esc_url(admin_url('admin-ajax.php')); ?>', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded; charset=utf-8'
            },
            body: `action=yourFunctionsAction`,
            credentials: 'same-origin'
        }).then(response => {
            return response.json();
        }).then(data => {
            if (data.status === 'true') {
                console.log('Do something...');
            }
        });
    }