wp_editor for custom post type doesn't save value

Question

I have done this so many times but facing problems with meta boxes and wp_editor these days, lot of notices, errors and strange behaviour.

I have been able to solve problem with meta boxes notices and save . The main problem was nonce. The nonce i was using was for plugin usage. But my code is inside the theme so now i am unable to save the value in metabox and no more notices for metaboxes.

But now i get notice Notice: Undefined variable: main_detail in for wp_editor. And it doesn't save the value after i hit publish/update

   <?php
function wpt_performer_posttype() {
  register_post_type( 'performer',
    array(
      'labels' => array(
        'name' => __( 'Performer' ),
        'singular_name' => __( 'performer' ),
        'add_new' => __( 'Add New performer' ),
        'add_new_item' => __( 'Add New performer' ),
        'edit_item' => __( 'Edit performer' ),
        'new_item' => __( 'Add New performer' ),
        'view_item' => __( 'View performer' ),
        'search_items' => __( 'Search performer' ),
        'not_found' => __( 'No performer found' ),
        'not_found_in_trash' => __( 'No performer found in trash' )
      ),
      'public' => true,
      'supports' => array( 'title','thumbnail','page-attributes' ),
      'capability_type' => 'post',
      'rewrite' => array("slug" => "performer"), // Permalinks format
      'menu_position' => 6,         
      'show_ui'=>true,
      'query_var'=>true,
      'register_meta_box_cb' => 'add_performer_metaboxes'

      )
  );
}
add_action( 'init', 'wpt_performer_posttype' );

/*Add featured thumbnails to the custom post type*/
add_theme_support( 'post-thumbnails' );
/*Now we add the meta boxes to the performer*/
// add_action('add_meta_boxes', 'add_performer_metaboxes');
function add_performer_metaboxes() {   
  add_meta_box('wpt_performer_lines', __('Extra fields'), 'wpt_performer_lines', 'performer', 'normal', 'high'); 
}

function wpt_performer_lines(){
  global $post;


  wp_nonce_field( 'my_meta_box', 'performermeta_noncename' );

  $short_description = get_post_meta($post->ID, '_short_description', true);

  echo '<label >';?><?php _e( 'short description:' );?></label>
  <?php echo '<br><textarea name="_short_description" rows="1" cols="90">'.$short_description.'</textarea>';?>

  <?php wp_editor( $main_detail, 'main_detail', array( 'textarea_name' => '_main_detail', 'textarea_rows' =>5, 'media_buttons' => false ) );  
}

function wpt_save_performer_meta($post_id, $post) {
  if ( ! isset( $_POST['performermeta_noncename'] ) ) {
        return;
    }

    // Verify that the nonce is valid.
    if ( ! wp_verify_nonce( $_POST['performermeta_noncename'], 'my_meta_box' ) ) {
        return;
    }
  if ( !current_user_can( 'edit_post', $post->ID ))
    return $post->ID;

  $performer_meta['_short_description'] = trim($_POST['_short_description']); 

  foreach ($performer_meta as $key => $value) { // Cycle through the $performer_meta array!
    if( $post->post_type == 'revision' ) return; // Don't store custom data twice
    $value = implode(',', (array)$value); // If $value is an array, make it a CSV (unlikely)
    if(get_post_meta($post->ID, $key, FALSE)) { // If the custom field already has a value
      update_post_meta($post->ID, $key, $value);
    } else { // If the custom field doesn't have a value
      add_post_meta($post->ID, $key, $value);
    }
    if(!$value) delete_post_meta($post->ID, $key); // Delete if blank
  }
}

add_action('save_post', 'wpt_save_performer_meta', 1, 2); // save the custom fields

?>

Answer 1

You forgot to declare the variable $main_detail. Since it's a meta field you need to retrieve it first before you add it.

$main_detail = get_post_meta($post->ID, '_main_detail', true);  

Also, I can see that some errors in your code.

echo '<label >';?><?php _e( 'short description:' );?></label>

Should be..

echo '<label >' . _e( "short description:" ) . '</label>';

And, you also need to add the key _main_detail in your $performer_meta array in order to save it.

Answer 2

In your wpt_save_performer_meta() function you are iterating through $performer_meta array and saving its values. But it has only one manually set key (_short_description) ... and its value is result of isset($_POST['_short_description']), which is probablay always true, and saved (or displayed) as 1.

So it should be like this:

$performer_meta['_short_description'] = trim($_POST['_short_description']);

But your code will not save _main_detail editor field, because its key does not exist in $performer_meta array.

Edit: Notice: Undefined variable: main_detail ... is there because the variable $main_detail is missing, but you are using it in wp_editor().