Get editor in Excerpt

Here is a code that will add text editor in Excerpt, simple add this function in function.php

add_action( ‘add_meta_boxes’, array ( ‘T5_Richtext_Excerpt’, ‘switch_boxes’ ) );

/**
* Replaces the default excerpt editor with TinyMCE.
*/
class T5_Richtext_Excerpt
{
/**
* Replaces the meta boxes.
*
* @return void
*/
public static function switch_boxes()
{
if ( ! post_type_supports( $GLOBALS[‘post’]->post_type, ‘excerpt’ ) )
{
return;
}

remove_meta_box(
‘postexcerpt’ // ID
, ” // Screen, empty to support all post types
, ‘normal’ // Context
);

add_meta_box(
‘postexcerpt2’     // Reusing just ‘postexcerpt’ doesn’t work.
,   __( ‘Excerpt’ )    // Title
,   array ( __CLASS__, ‘show’ ) // Display function
,   null              // Screen, we use all screens with meta boxes.
,   ‘normal’          // Context
,   ‘core’            // Priority
);
}

/**
* Output for the meta box.
*
* @param object $post
* @return void
*/
public static function show( $post )
{
?>
<label for=”excerpt”><?php
_e( ‘Excerpt’ )
?></label>
<?php
// We use the default name, ‘excerpt’, so we don’t have to care about
// saving, other filters etc.
wp_editor(
self::unescape( $post->post_excerpt ),
‘excerpt’,
array (
‘textarea_rows’ => 15
,   ‘media_buttons’ => TRUE
,   ‘teeny’         => TRUE
,   ‘tinymce’       => TRUE
)
);
}

/**
* The excerpt is escaped usually. This breaks the HTML editor.
*
* @param string $str
* @return string
*/
public static function unescape( $str )
{
return str_replace(
array ( ‘<’, ‘>’, ‘"’, ‘&’, ‘ ’, ‘&nbsp;’ )
, array ( ‘<‘, ‘>’, ‘”‘, ‘&’, ‘ ‘, ‘ ‘ )
, $str
);
}
}