Tạo các Tabs nội dung trong wordpress admin

// Create WP Admin Tabs on-the-fly.
function admin_tabs($tabs, $current=NULL){
    if(is_null($current)){
        if(isset($_GET['page'])){
            $current = $_GET['page'];
        }
    }
    $content = '';
    $content .= '<h2 class="nav-tab-wrapper">';
    foreach($tabs as $location => $tabname){
        if($current == $location){
            $class = ' nav-tab-active';
        } else{
            $class = '';    
        }
        $content .= '<a class="nav-tab'.$class.'" href="?tab='.$location.'">'.$tabname.'</a>';
    }
    $content .= '</h2>';
        return $content;
}

$my_plugin_tabs = array(
    'my-plugin-tab1' => 'tab 1',
    'my-plugin-tab2' => 'tab 2',
    'my-plugin-tab3' => 'tab 3'
);
 
echo admin_tabs($my_plugin_tabs);

if(isset($_GET['tab'])){
switch($_GET['tab']){
	case 'my-plugin-tab1':
	?>
		tab 1 content
	< ?php
	break;
	case 'my-plugin-tab2':
	?>
		tab 2 content
	< ?php
	break;
	case 'my-plugin-tab3':
	?>
		tab 3 content
	< ?php
	break;
	default:;
}
}

add_submenu_page( 'themes.php', 'My Theme Options', 'My Theme Options', 'administrator', 'my-theme-slug', 'settings_page');

function ilc_settings_page() {
   global $pagenow;
   $settings = get_option( "ilc_theme_settings" );
 
//generic HTML and code goes here
 
if ( isset ( $_GET['tab'] ) ) ilc_admin_tabs($_GET['tab']); else ilc_admin_tabs('homepage');

<form method="post" action="<?php admin_url( 'themes.php?page=theme-settings' ); ?>">
< ?php
wp_nonce_field( "ilc-settings-page" ); 
 
if ( $pagenow == 'themes.php' && $_GET['page'] == 'theme-settings' ){
 
   if ( isset ( $_GET['tab'] ) ) $tab = $_GET['tab'];
   else $tab = 'homepage';
 
   echo '<table class="form-table">';
   switch ( $tab ){
      case 'general' :
         ?>
         <tr>
            <th>Tags with CSS classes:</th>
            <td>
               <input id="ilc_tag_class" name="ilc_tag_class" type="checkbox" <?php if ( $settings["ilc_tag_class"] ) echo 'checked="checked"'; ?/> value="true" />
               <label for="ilc_tag_class">Checking this will output each post tag with a specific CSS class based on its slug.</label>
            </td>
         </tr>
         < ?php
      break;
      case 'footer' :
         ?>
         <tr>
            <th><label for="ilc_ga">Insert tracking code:</label></th>
            <td>
               Enter your Google Analytics tracking code:
               <textarea id="ilc_ga" name="ilc_ga" cols="60" rows="5">< ?php echo esc_html( stripslashes( $settings["ilc_ga"] ) ); ?></textarea><br />
 
            </td>
         </tr>
         < ?php
      break;
      case 'homepage' :
         ?>
         <tr>
            <th><label for="ilc_intro">Introduction</label></th>
            <td>
               Enter the introductory text for the home page:
               <textarea id="ilc_intro" name="ilc_intro" cols="60" rows="5" >< ?php echo esc_html( stripslashes( $settings["ilc_intro"] ) ); ?></textarea>
            </td>
         </tr>
         < ?php
      break;
   }
   echo '</table>';
}
 
?>
   <p class="submit" style="clear: both;">
      <input type="submit" name="Submit"  class="button-primary" value="Update Settings" />
      <input type="hidden" name="ilc-settings-submit" value="Y" />
   </p>
</form>

function ilc_save_theme_settings() {
   global $pagenow;
   $settings = get_option( "ilc_theme_settings" );
 
   if ( $pagenow == 'themes.php' && $_GET['page'] == 'theme-settings' ){
      if ( isset ( $_GET['tab'] ) )
           $tab = $_GET['tab'];
       else
           $tab = 'homepage';
 
       switch ( $tab ){
           case 'general' :
         $settings['ilc_tag_class'] = $_POST['ilc_tag_class'];
      break;
           case 'footer' :
         $settings['ilc_ga'] = $_POST['ilc_ga'];
      break;
      case 'homepage' :
         $settings['ilc_intro'] = $_POST['ilc_intro'];
      break;
       }
   }
   //code to filter html goes here
   $updated = update_option( "ilc_theme_settings", $settings );
}

function ilc_load_settings_page() {
  if ( $_POST["ilc-settings-submit"] == 'Y' ) {
   check_admin_referer( "ilc-settings-page" );
   ilc_save_theme_settings();
 
   $url_parameters = isset($_GET['tab'])? 'updated=true&tab='.$_GET['tab'] : 'updated=true';
   wp_redirect(admin_url('themes.php?page=theme-settings&'.$url_parameters));
   exit;
  }
}