TinyMCE Custom Formats in WordPRess

tinymce-custom-formats.php

<?php
add_filter( 'tiny_mce_before_init', 'icreate__custom_tinymce_formats' );  
function icreate__custom_tinymce_formats( $init_array ) {  
	// Define the style_formats array
	$style_formats = array(   
		array(  
			'title' => '.blockquote-alt',  
			'block' => 'blockquote',  
			'classes' => 'blockquote-alt',
			'wrapper' => true,
			
			),  
		);  
	// Insert the array, JSON ENCODED, into 'style_formats'
	$init_array['style_formats'] = json_encode( $style_formats );  
	
	return $init_array;  

}