Dynamic validation helper.

Validator.js

/**
 * Validator Class 
 */
define([
  'jquery',
  'underscore'
  ], function($, _){

    var Validator = {

        noSpecials: function(event) {
          var regex = new RegExp("^[a-zA-Z0-9]+$");
          var key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
          var keycode = event.keyCode ? event.keyCode : event.charCode;
          if ((!regex.test(key)) && (keycode != 8) && (keycode != 9)) {
            event.preventDefault();
            return false;
          }
        },

        noBlankSpace: function(event) {
          var code = (event.keyCode ? event.keyCode : event.which);
          if (code == 32) {
            event.preventDefault();
            return false;
          }
        },

        noNumbers: function(event) {
          var a = [];
          var k = event.which;
          if ($.browser.msie && ($.browser.version < 9)) {
            var k = event.keyCode ? event.keyCode : event.charCode;
            if (k >= 48 && k <= 57)
              event.preventDefault();
          } else {
            for (i = 48; i < 58; i++)
              a.push(i);
            if ((a.indexOf(k) >= 0))
              event.preventDefault();
          }
        },

        onlyNumbers: function(event) {
          var char = (event.which) ? event.which : event.keyCode
          if (char > 31 && (char < 48 || char > 57)) {
            event.preventDefault();
            return false;
          }
          
          return true;
        },

        onlyLoweCase: function(event) {
          var char = (event.which) ? event.which : event.keyCode;
              string = String.fromCharCode(char);
          if(string.match(/[A-Z]/)) {
            event.preventDefault();
            return false;
          }
          return true;
        }
        
      }
 
    return Validator;

  }); 
  
/**
 * Usage on View
 *events: {
 *    'keypress .no-scpecials': function(event){
 *        Validator.noSpecials(event);
 *    }
 *},
 */