placeholder.js

placeholder.jquery.js

(function( $, document ){

  var enablePlaceholders = {
    init: function( el ){
      var $t = this, $ = jQuery;
      $t.el = $(el).data( 'hasplaceholder', true );
      $t.placeholder = $t.el.attr('placeholder');
      $t.addPlaceholder( $t.el );
    } // init

    ,clearValue: function( e ){
      if( $(e).val() === $(e).data('placeholder') ) {
        $(e).val('');
      }
    }//clearValue

    ,addPlaceholder: function(){
      var $t = this;
        $t.maybeShowPlaceholder();
      $t.el.bind('blur.ntz_placeholder', $.proxy( $t.maybeShowPlaceholder, $t ) );
      $t.el.bind('focus.ntz_placeholder', $.proxy( $t.maybeHidePlaceholder, $t ) );
    } //addPlaceholder

    ,maybeShowPlaceholder: function(){
      var $t = this;
      if( $.trim( $t.el.val() ) !== '' ){ return; }
      $t.el
        .addClass('placeholder')
        .val( $t.placeholder );
    }//maybeShowPlaceholder

    ,maybeHidePlaceholder: function(){
      var $t = this;
      if( $t.el.hasClass('placeholder') && 
          $t.el.val() == $t.placeholder ){
        $t.el.val('')
      } 
    }//maybeHidePlaceholder
  };

  $.fn.enablePlaceholders = function() {
    var fakeInput = document.createElement("input"),
        nativePlaceholder = ("placeholder" in fakeInput);

    if (!nativePlaceholder) {

      $('input[placeholder], textarea[placeholder]').filter(function(){
        return !$(this).data('hasplaceholder')
      }).each(function(){
        var obj = Object.create( enablePlaceholders );
        obj.init( this );
      });

      return this;
    }
  };

})( jQuery, document );