function room_facility_custom_meta() {
    add_meta_box( 'room_facility_meta', __( 'Meta Box ', 'room_facility-textdomain' ), 'room_facility_meta_callback', 'room_type' );
}
add_action( 'add_meta_boxes', 'room_facility_custom_meta' );

function room_facility_meta_callback( $post ) {
    //nonce_field
    wp_nonce_field( basename( __FILE__ ), 'room_facility_nonce' );

    $tax = "room_facility";
    $term_facilities = get_terms( $tax, array('hide_empty' => false));
    $term_checked_facilities= wp_get_post_terms($post->ID, $tax);

    foreach($term_facilities as $term){

        $room_facility_id = $term->term_id;
        /* the meta_key for postmeta, note there is the room_facility included,
         * since there should be a relationship between post_id (in this case from taxonomy "room_type")
         * and "room_facility"
         */
        $meta_key = "_room_facility_key_".$room_facility_id;
        //value from the postmeta
        $room_facility_value = get_post_meta($post->ID, $meta_key);

    ?>
        <div class="row">
                <label for="checkbox_<?php echo $room_facility_id ?>">
                    <input type="checkbox" name="checkbox_<?php echo $room_facility_id ?>" id="checkbox_<?php echo $room_facility_id ?>"  <?php checked( myArrayContainsWord($term_checked_facilities, $term->term_id)); ?> />
                    <?php _e( $term->name, 'prfx-textdomain' )?>
                </label>
                <input type="text" name="text_<?php echo $room_facility_id ?>" id="text_<?php echo $room_facility_id ?>" value="<?php if ( !empty ( $room_facility_value[0] ) ){ echo $room_facility_value[0]; }?>" />
        </div>
    <?php
    } //end foreach
}

function room_facility_meta_save( $post_id )
    {
          // Verify this came from the our screen and with proper authorization,
          // because save_post can be triggered at other times
          //if ( !wp_verify_nonce( $_POST['room_facility_nonce'], plugin_basename(__FILE__) )) { <-- THIS DIDN'T WORK
           if(! isset( $_POST['room_facility_nonce'] )){
                return $post_id;
              }

           // Verify if this is an auto save routine. If it is our form has not been submitted, so we dont want
          // to do anything


   if ( defined('DOING_AUTOSAVE') && DOING_AUTOSAVE )
        return $post_id;


          //wp_set_object_terms( 742, array(211), 'room_facility');
          $taxonomy = "room_facility";
          $term_facilities = get_terms( $taxonomy, array('hide_empty' => false));

          foreach ($term_facilities as $tax => $term)
          {
            $room_facility_id = $term->term_id;

            /* the meta_key for postmeta, note there is the room_facility included,
             * since there should be a relationship between post_id (in this case from taxonomy "room_type")
             * and "room_facility"
             */
            $meta_key = "_room_facility_key_".$room_facility_id;

            //update postmeta room_facility_key_<ID>
            if( isset( $_POST[ "text_".$room_facility_id] ) ) {
                update_post_meta( $post_id, $meta_key, sanitize_text_field( $_POST[ "text_".$room_facility_id] ) );
            }

            //set wp_term_relationships for room_type and room_facility
            if( isset( $_POST[ 'checkbox_'.$room_facility_id ] ) )
            {
                //wp_set_post_terms( $post_id, $term, $taxonomy); <-- WRONG function
                wp_set_object_terms( $post_id, array($term->term_id) , $taxonomy);
            } /*else {
                wp_set_post_terms( $post_id, $term, $taxonomy);
            }*/
          }
}
add_action( 'save_post', 'room_facility_meta_save' );

echo '<script>alert("test")</script>';