Placeholder polyfill (Drupal behavior)

placeholder.js

// As seen in bozo/custom.js

(function($) {

Drupal.behaviors.placeholderPolyfill = {
  attach: function(context, settings) {

    if ( !('placeholder' in document.createElement('input')) ) {
      var onFocus = function(e) {
        this.$this || (this.$this = $(this));
        if ( this.value == this.$this.attr('placeholder') ) {
          this.value = '';
          this.$this.removeClass('showing-placeholder');
        }
      };
    
      var onBlur = function(e) {
        this.$this || (this.$this = $(this));
        if ( this.value == '' ) {
          this.value = this.$this.attr('placeholder');
          this.$this.addClass('showing-placeholder');
        }
      };
      
      var formClearPlaceholders = function(placeholdered) {
        $.each(placeholdered, function(i, el) {
          onFocus.call(el);
        });
        
        // @TODO Is there a better way to be the very last?
        setTimeout(function() {
          $.each(placeholdered, function(i, el) {
            onBlur.call(el);
          });
        }, 50);
      };
      
      // Find all placeholder elements and attach events
      $('input[placeholder], textarea[placeholder]')
      .bind('focus', onFocus)
      .bind('blur', onBlur)
      .each(function(i, el) {
        onBlur.call(el);
  
        // Has form and form wasn't placeholdered yet.
        if ( el.form && !el.form.$placeholdered ) {
          el.form.$placeholdered = [el];
          
          var $form = $(el.form);
          
          var submitId = $form.find('.form-submit').attr('id');
          if (Drupal.ajax && Drupal.ajax[submitId]) {
            var ajax = Drupal.ajax[submitId];
            ajax.options.beforeSerialize = function(element_settings, options) {
              formClearPlaceholders(ajax.element.form.$placeholdered);
              return ajax.beforeSerialize(element_settings, options);
            };
          }
          
          // Remove placeholders on submit.
          $form.bind('submit', function(e) {
            formClearPlaceholders(this.$placeholdered);
          });
          
          // Move new submit to the start.
          var listeners = $form.data('events').submit;
          listeners.unshift(listeners.pop());
        }
        // Has form, so add to placeholdered stack.
        else if ( el.form ) {
          el.form.$placeholdered.push(el);
        }
      });
    }

  }
};

})(jQuery);