Add Editor Style from Plugin

In WordPress 3.0.0 WP introduce add_editor_style() function to easily add custom stylesheet for WordPress TinyMCE visual editor. But you can also add them from a plugin.

It’s useful if you add a plugin to add dropdown style in visual editor, or you can also use this in a theme, if your theme add a visual editor in front end because add_editor_style() only load in admin. For example for bbPress supported theme.

/* Add Editor Style */
add_filter( 'mce_css', 'my_plugin_editor_style' );

/**
 * Add Editor Style
 * add additional editor style for my-plugin
 * 
 * @since 0.1.0
 */
function my_plugin_editor_style( $mce_css ){

    $mce_css .= ', ' . plugins_url( 'css/editor-style.css', __FILE__ );
    return $mce_css;
}

now you just need to add your additional CSS for visual editor in editor-style.css in css folder in your plugin.