// LiveValidation 1.3 (standalone version)
// Copyright (c) 2007-2008 Alec Hill (www.livevalidation.com)
// LiveValidation is licensed under the terms of the MIT License

// MW: 20100316: Adapted for async usage with Zotonic.
// MW: 20100629: Added support for presence check on radio buttons
// MW: 20110329: Dynamically fetch the validation fields from the DOM, this makes it
//               possible to add/remove fields dynamically.

/*********************************************** LiveValidation class ***********************************/


function addLiveValidation(element, args) {
	if (!$(element).data("z_live_validation"))
		$(element).data("z_live_validation", new LiveValidation($(element).attr('id'), args));
}


function getLiveValidation(element) {
	return $(element).data("z_live_validation");
}


/**
 *  validates a form field in real-time based on validations you assign to it
 *  
 *  @var element {mixed} - either a dom element reference or the string id of the element to validate
 *  @var optionsObj {Object} - general options, see below for details
 *
 *  optionsObj properties:
 *              validMessage {String}   - the message to show when the field passes validation
 *                            (DEFAULT: "Thankyou!")
 *              onAsync {Function}    - function to execute when field passes is waiting for async validation
 *                            (DEFAULT: function(){ this.insertMessage(this.createSpinnerSpan()); this.addFieldClass(); } ) 
 *              onValid {Function}    - function to execute when field passes validation
 *                            (DEFAULT: function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); } ) 
 *              onInvalid {Function}  - function to execute when field fails validation
 *                            (DEFAULT: function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); })
 *              insertAfterWhatNode {Int}   - position to insert default message
 *                            (DEFAULT: the field that is being validated)  
 *              onlyOnBlur {Boolean} - whether you want it to validate as you type or only on blur
 *                            (DEFAULT: false)
 *              wait {Integer} - the time you want it to pause from the last keystroke before it validates (ms)
 *                            (DEFAULT: 0)
 *              onlyOnSubmit {Boolean} - whether should be validated only when the form it belongs to is submitted
 *                            (DEFAULT: false)            
 */

var LiveValidation = function(element, optionsObj){
    this.initialize(element, optionsObj);
}

LiveValidation.VERSION = '1.3 standalone';

/** element types constants ****/

LiveValidation.TEXTAREA = 1;
LiveValidation.TEXT     = 2;
LiveValidation.PASSWORD = 3;
LiveValidation.CHECKBOX = 4;
LiveValidation.SELECT   = 5;
LiveValidation.FILE     = 6;
LiveValidation.RADIO    = 7;


/****** prototype ******/

LiveValidation.prototype = 
{

    validClass: 'z_valid',
    invalidClass: 'z_invalid',
    messageClass: 'z_validation_message',
    validFieldClass: 'z_valid_field',
    invalidFieldClass: 'form-field-error',
    asyncFieldClass: 'z_async_validation',

    /**
     *  initialises all of the properties and events
     *
     * @var - Same as constructor above
     */
    initialize: function(element, optionsObj){
      var self = this;
      if(!element)
        throw new Error("LiveValidation::initialize - No element reference or element id has been provided!");
      this.element = element.nodeName ? element : document.getElementById(element);
      if(!this.element) 
        throw new Error("LiveValidation::initialize - No element with reference or id of '" + element + "' exists!");
      // default properties that could not be initialised above
      this.validations = [];
      this.elementType = this.getElementType();
      this.form = this.element.form;
      // options
      var options = optionsObj || {};
      this.validMessage = options.validMessage || '';
      var node = options.insertAfterWhatNode || this.element;
      this.insertAfterWhatNode = node.nodeType ? node : document.getElementById(node);
      this.onAsync = options.onAsync || function(){ this.insertSpinner(this.createSpinnerSpan()); this.addFieldClass(); };
      this.onValid = options.onValid || function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };
      this.onInvalid = options.onInvalid || function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };  
      this.onlyOnBlur =  options.onlyOnBlur || false;
      this.wait = options.wait || 0;
      this.onlyOnSubmit = options.onlyOnSubmit || false;
      this.validationAsync = false;
      
      // Initialize the form hooks, remember the LiveValidationForm object.
      var theForm = $(this.element).closest("form");
      if(theForm.length){
        this.formObj = LiveValidationForm.getInstance(theForm[0]);
      }

      // events
      // collect old events
      this.oldOnFocus = this.element.onfocus || function(){};
      this.oldOnBlur = this.element.onblur || function(){};
      this.oldOnClick = this.element.onclick || function(){};
      this.oldOnChange = this.element.onchange || function(){};
      this.oldOnKeyup = this.element.onkeyup || function(){};
      this.element.onfocus = function(e){ self.doOnFocus(e); return self.oldOnFocus.call(this, e); }
      if(!this.onlyOnSubmit){
        switch(this.elementType){
          case LiveValidation.RADIO:
          case LiveValidation.CHECKBOX:
            this.element.onclick = function(e){ self.validate(); return self.oldOnClick.call(this, e); }
          // let it run into the next to add a change event too
          case LiveValidation.SELECT:
          case LiveValidation.FILE:
            this.element.onchange = function(e){ self.validate(); return self.oldOnChange.call(this, e); }
            break;
          default:
            if(!this.onlyOnBlur) this.element.onkeyup = function(e){ self.deferValidation(); return self.oldOnKeyup.call(this, e); }
            this.element.onblur = function(e){ self.doOnBlur(e); return self.oldOnBlur.call(this, e); }
        }
      }
    },
  
    /**
     *  destroys the instance's events (restoring previous ones) and removes it from any LiveValidationForms
     */
    destroy: function(){
        // remove events - set them back to the previous events
        this.element.onfocus = this.oldOnFocus;
        if(!this.onlyOnSubmit){
            switch(this.elementType){
              case LiveValidation.RADIO:
              case LiveValidation.CHECKBOX:
                this.element.onclick = this.oldOnClick;
              // let it run into the next to add a change event too
              case LiveValidation.SELECT:
              case LiveValidation.FILE:
                this.element.onchange = this.oldOnChange;
                break;
              default:
                if(!this.onlyOnBlur) this.element.onkeyup = this.oldOnKeyup;
                this.element.onblur = this.oldOnBlur;
            }
        }
        this.validations = [];
        this.removeMessageAndFieldClass();
    },
    
    /**
     * Adds a validation to perform to a LiveValidation object
     *
     * @var validationFunction {Function} - validation function to be used (ie Validate.Presence )
     * @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     * @return {Object} - the LiveValidation object itself so that calls can be chained
     */
    add: function(validationFunction, validationParamsObj){
      this.validations.push( {type: validationFunction, params: validationParamsObj || {} } );
      return this;
    },
    
    /**
     * Removes a validation from a LiveValidation object - must have exactly the same arguments as used to add it 
     *
     * @var validationFunction {Function} - validation function to be used (ie Validate.Presence )
     * @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     * @return {Object} - the LiveValidation object itself so that calls can be chained
     */
    remove: function(validationFunction, validationParamsObj){
        var found = false;
        for( var i = 0, len = this.validations.length; i < len; i++ ){
            if( this.validations[i].type == validationFunction ){
                if (this.validations[i].params == validationParamsObj) {
                  found = true;
                  break;
                }
            }
        }
        if(found) this.validations.splice(i,1);
        return this;
    },
    
  
    /**
     * makes the validation wait the alotted time from the last keystroke 
     */
    deferValidation: function(e){
      if(this.wait >= 300) this.removeMessageAndFieldClass();
      var self = this;
      if(this.timeout) clearTimeout(self.timeout);
      this.timeout = setTimeout( function(){ self.validate() }, self.wait); 
    },
        
    /**
     * sets the focused flag to false when field loses focus 
     */
    doOnBlur: function(e){
      this.focused = false;
      this.validate(e);
    },
        
    /**
     * sets the focused flag to true when field gains focus 
     */
    doOnFocus: function(e){
      this.focused = true;
      this.removeMessageAndFieldClass();
    },
    
    /**
     *  gets the type of element, to check whether it is compatible
     *
     *  @var validationFunction {Function} - validation function to be used (ie Validate.Presence )
     *  @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     */
    getElementType: function(){
        var nodeName = this.element.nodeName.toUpperCase();
        if (nodeName == 'TEXTAREA')
            return LiveValidation.TEXTAREA;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'TEXT')
            return LiveValidation.TEXT;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'PASSWORD')
            return LiveValidation.PASSWORD;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'CHECKBOX')
            return LiveValidation.CHECKBOX;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'FILE')
            return LiveValidation.FILE;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'RADIO')
            return LiveValidation.RADIO;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'EMAIL')
            return LiveValidation.TEXT;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'TEL')
            return LiveValidation.TEXT;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'NUMBER')
            return LiveValidation.TEXT;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'URL')
            return LiveValidation.TEXT;
        if (nodeName == 'INPUT' && this.element.type.toUpperCase() == 'HIDDEN')
            return LiveValidation.TEXT;
        if (nodeName == 'SELECT')
            return LiveValidation.SELECT;
        if (nodeName == 'INPUT')
            throw new Error('LiveValidation::getElementType - Cannot use LiveValidation on an ' + this.element.type + ' input!');
        throw new Error('LiveValidation::getElementType - Element must be an input, select, or textarea!');
    },
    
    /**
     * Loops through all the validations added to the LiveValidation object and checks them one by one
     *
     * @var validationFunction {Function} - validation function to be used (ie Validate.Presence )
     * @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     * @return {Boolean} - whether the all the validations passed or if one failed
     */
    doValidations: function(isSubmit, submitTrigger){
        var result;

        this.validationFailed = false;
        this.validationAsync = false;
        for(var i = 0, len = this.validations.length; i < len; ++i){
            var validation = this.validations[i];
            switch(validation.type){
                case Validate.Presence:
                case Validate.Confirmation:
                case Validate.Acceptance:
                  this.displayMessageWhenEmpty = true;
                  result = this.validateElement(validation.type, validation.params, isSubmit, submitTrigger); 
                  break;
                default:
                  result = this.validateElement(validation.type, validation.params, isSubmit, submitTrigger);
                  break;
            }
            this.validationFailed = !result;
            if(this.validationFailed) return false; 
          }
          this.message = this.validMessage;
          return true;
    },

    /**
     * Check if there is an async validation.
     */
    isAsync: function (){
        for(var i = 0, len = this.validations.length; i < len; ++i) {
            var validation = this.validations[i];
            if (validation.type == Validate.Postback)
                return true;
        }
        return false;
    },
    
    /**
     * Performs validation on the element and handles any error (validation or otherwise) it throws up
     *
     * @var validationFunction {Function} - validation function to be used (ie Validate.Presence )
     * @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     * @var isSubmit {Boolean} - is this a form submit or an individual field check
     * @var submitTrigger {Object} - the element that triggered the submit
     * @return {Boolean} or {"async"} - whether the validation has passed, failed or waits for an async server side check
     */
    validateElement: function(validationFunction, validationParamsObj, isSubmit, submitTrigger){
        var value = this.getValue();
        if(validationFunction == Validate.Acceptance){
            if(this.elementType != LiveValidation.CHECKBOX) 
                throw new Error('LiveValidation::validateElement - Element to validate acceptance must be a checkbox!');
            value = this.element.checked;
        }
        var isValid = true;
        try {
            isValid = validationFunction(value, validationParamsObj, isSubmit, submitTrigger);
            if (isValid == 'async') {
                this.validationAsync = true;
            }
        } 
        catch(error) {
            if(error instanceof Validate.Error){
                if( value !== '' || (value === '' && this.displayMessageWhenEmpty) ){
                    this.validationFailed = true;
                    this.message = error.message;
                    isValid = false;
                }
            } else {
                throw error;
            }
        }
        return isValid;
    },
    
    
    getValue: function() {
		switch (this.elementType) {
		case LiveValidation.SELECT:
			if (this.element.selectedIndex >= 0) return this.element.options[this.element.selectedIndex].value;
			else return "";
		case LiveValidation.RADIO:
			var val = $('input[name='+this.element.name+']:checked').val();
			return val;
		default:
			return this.element.value;
		}
    },

    /**
     * Do all the validations and fires off the onValid or onInvalid callbacks
     *
     * @var isSubmit {Boolean} - is this a form submit or an individual field check
     * @var submitTrigger {Object} - the element that triggered the submit
     * @return {Boolean} - whether all the validations passed or if one failed
     */
    validate: function(isSubmit, submitTrigger){
        if(!this.element.disabled) {
            var isValid = this.doValidations(isSubmit, submitTrigger);
            if (this.validationAsync) {
                this.onAsync();
                return false;
            } else if (isValid) {
                this.onValid();
                return true;
            } else {
                this.onInvalid();
                return false;
            }
        } else {
            return true;
        }
    },
  
    /**
     * Called when there is an async validation result.
     * The caller has already checked if the current input value hasn't changed.
     */
    asyncValidationResult: function(isValid){
        if (this.validationAsync){
            // Find which validation was waiting for async, assume only one async postback per field.
            for(var i = 0, len = this.validations.length; i < len; ++i){
                var validation = this.validations[i];
                if(validation.type == Validate.Postback){
                    // Clear the async wait flag
                    this.validationAsync = false;
                    this.validationFailed = !isValid;
                    if (isValid){
                        this.onValid();
                    } else {
                        this.onInvalid();
                    }
                    this.formObj.asyncResult(this, isValid)
                }
            }
        }
    },
    
    /**
     *  enables the field
     *
     *  @return {LiveValidation} - the LiveValidation object for chaining
     */
    enable: function(){
        this.element.disabled = false;
        return this;
    },

    /**
     *  disables the field and removes any message and styles associated with the field
     *
     *  @return {LiveValidation} - the LiveValidation object for chaining
     */
    disable: function(){
        this.element.disabled = true;
        this.removeMessageAndFieldClass();
        return this;
    },
    
    /** Message insertion methods ****************************
     * 
     * These are only used in the onValid and onInvalid callback functions and so if you overide the default callbacks,
     * you must either impliment your own functions to do whatever you want, or call some of these from them if you 
     * want to keep some of the functionality
     */
 
     /**
      *  makes a span containing a spinner image
      *
      * @return {HTMLSpanObject} - a span element with the message in it
      */
     createSpinnerSpan: function(){
         var span = document.createElement('span');
         span.innerHTML = '<img src="/lib/images/spinner.gif" height="16" width="16" alt="Validating..." />';
         return span;
     },
   
    /**
     *  makes a span containg the passed or failed message
     *
     * @return {HTMLSpanObject} - a span element with the message in it
     */
    createMessageSpan: function(){
        var span = document.createElement('span');
        var textNode = document.createTextNode(this.message);
        span.appendChild(textNode);
        return span;
    },
    
    /**
     * Show an error message
     */
    showErrorMessage: function(message){
        this.message = message;
        this.onInvalid();
    },
    
    /** 
     * Insert a spinner in the message element.
     */
    insertSpinner: function (elementToInsert){
        this.removeMessage();
        if( (this.displayMessageWhenEmpty && (this.elementType == LiveValidation.CHECKBOX || this.element.value == ''))
          || this.element.value != '' ){

          elementToInsert.className += ' ' + this.messageClass + ' ' + this.asyncFieldClass;
          if(this.insertAfterWhatNode.nextSibling){
              this.insertAfterWhatNode.parentNode.insertBefore(elementToInsert, this.insertAfterWhatNode.nextSibling);
          }else{
              this.insertAfterWhatNode.parentNode.appendChild(elementToInsert);
          }
        }
        
    },
    
    /**
     *  inserts the element containing the message in place of the element that already exists (if it does)
     *
     * @var elementToIsert {HTMLElementObject} - an element node to insert
     */
    insertMessage: function(elementToInsert){
        this.removeMessage();
	if( (this.displayMessageWhenEmpty && (this.elementType == LiveValidation.CHECKBOX || this.element.value == ''))
	    || this.element.value != '' ) {
                
	        var className = this.validationFailed ? this.invalidClass : this.validClass;
	        elementToInsert.className += ' ' + this.messageClass + ' ' + className;
	        if(this.insertAfterWhatNode.nextSibling){
	            this.insertAfterWhatNode.parentNode.insertBefore(elementToInsert, this.insertAfterWhatNode.nextSibling);
	        }else{
	            this.insertAfterWhatNode.parentNode.appendChild(elementToInsert);
	        }
	    }
    },
    
    
    /**
     *  changes the class of the field based on whether it is valid or not
     */
    addFieldClass: function(){
        this.removeFieldClass();
        if(!this.validationFailed){
            if(this.displayMessageWhenEmpty || this.element.value != ''){
				switch (this.elementType) {
				case LiveValidation.RADIO:
	            	$('input[name='+this.element.name+']').closest('label').addClass(this.validFieldClass);
					break;
				default:
                	$(this.element).addClass(this.validFieldClass);
					break;
				}
            }
        }else{
			switch (this.elementType) {
			case LiveValidation.RADIO:
            	$('input[name='+this.element.name+']').closest('label').addClass(this.invalidFieldClass);
				break;
			default:
            	$(this.element).addClass(this.invalidFieldClass);
				break;
			}
        }
    },
    
    /**
     *  removes the message element if it exists, so that the new message will replace it
     */
    removeMessage: function(){
      var nextEl;
      var el = this.insertAfterWhatNode;
      while(el.nextSibling){
          if(el.nextSibling.nodeType === 1){
            nextEl = el.nextSibling;
            break;
        }
        el = el.nextSibling;
      }
        if(nextEl && nextEl.className.indexOf(this.messageClass) != -1) this.insertAfterWhatNode.parentNode.removeChild(nextEl);
    },
    
    /**
     *  removes the class that has been applied to the field to indicate if valid or not
     */
    removeFieldClass: function(){
		switch (this.elementType) {
		case LiveValidation.RADIO:
        	$('input[name='+this.element.name+']').closest('label').removeClass(this.invalidFieldClass).removeClass(this.validFieldClass);
			break;
		default:
    		$(this.element).removeClass(this.invalidFieldClass).removeClass(this.validFieldClass);
			break;
		}
    },
        
    /**
     *  removes the message and the field class
     */
    removeMessageAndFieldClass: function(){
      this.removeMessage();
      this.removeFieldClass();
    }

} // end of LiveValidation class




/*************************************** LiveValidationForm class ****************************************/
/**
 * This class is used internally by LiveValidation class to associate a LiveValidation field with a form it is icontained in one
 * 
 * It will therefore not really ever be needed to be used directly by the developer, unless they want to associate a LiveValidation 
 * field with a form that it is not a child of
 */

/**
   *  handles validation of LiveValidation fields belonging to this form on its submittal
   *  
   *  @var element {HTMLFormElement} - a dom element reference to the form to turn into a LiveValidationForm
   */
var LiveValidationForm = function(element){
  this.initialize(element);
}

/**
   *  gets the instance of the LiveValidationForm if it has already been made or creates it if it doesnt exist
   *  
   *  @var element {HTMLFormElement} - a dom element reference to a form
   */
LiveValidationForm.getInstance = function(element){
  var rand = Math.random() * Math.random();
  if(!$(element).attr("id"))
    $(element).attr("id", 'formId_' + rand.toString().replace(/\./, '') + new Date().valueOf());
  var instance = $(element).data("z_live_validation_instance");
  if (!instance) {
      instance = new LiveValidationForm(element);
      $(element).data("z_live_validation_instance", instance);
  }
  return instance;
}

LiveValidationForm.prototype = {
  validFormClass: 'z_form_valid',
  invalidFormClass: 'z_form_invalid',

  /**
   *  constructor for LiveValidationForm - handles validation of LiveValidation fields belonging to this form on its submittal
   *  
   *  @var element {HTMLFormElement} - a dom element reference to the form to turn into a LiveValidationForm
   */
  initialize: function(element){
    this.name = $(element).attr("id");
    this.element = element;
    this.skipValidations = 0;
    this.submitWaitForAsync = new Array();

    // preserve the old onsubmit event
    this.oldOnSubmit = this.element.onsubmit || function(){};
    var self = this;

    this.onInvalid = function() { 
		$(this).removeClass("z_form_valid").addClass("z_form_invalid"); 
		$(".z_form_valid", this).hide();
		$(".z_form_invalid", this).fadeIn();
	};
    this.onValid = function() { 
		$(this).removeClass("z_form_invalid").addClass("z_form_valid");
		$(".z_form_invalid", this).hide();
		$(".z_form_valid", this).fadeIn();
	};

    $(element).submit(function(event) {
        event.zIsValidated = true;
        if (self.skipValidations == 0) {
            var result = true;
            var async = new Array();
            var is_first = true;

			var fields = self.getFields();
            for(var i = 0, len = fields.length; i < len; ++i ) {
                if (!fields[i].element.disabled) {
                    if (fields[i].isAsync()) {
                        async.push(fields[i]);
                    } else {
						var valid = fields[i].validate(true, this.clk);
                        result = result && valid;
                    }
                }
            }

            if (async.length > 0){
                if (result)
					self.submitWaitForAsync = async;
				else 
					self.onInvalid.call(this);

                for(var i=0; i<async.length; i++){
                    async[i].validate(true, this.clk);
                }
                result = false;
            }
			else if (!result) {
				self.onInvalid.call(this);
			}
            
            if (!result) {
                // Either validation failed or we are waiting for more async results.
                event.stopImmediatePropagation();
                return false;
            } else {
				self.onValid.call(this);
                return z_form_submit_validated_do(event);
            }
        } else {
            self.skipValidations--;
            if (self.skipValidations == 0) {
				self.onValid.call(this);
                return z_form_submit_validated_do(event);
            } else {
                return false;
			}
        }
    })
  },
  
  /**
   *  destroy this instance and its events
   *
   * @var force {Boolean} - whether to force the destruction even if there are fields still associated
   */
  destroy: function(force){
	if (force || this.getFields().length == 0) {
	    // remove events - set back to previous events
	    this.element.onsubmit = this.oldOnSubmit;
	    // remove from the instances namespace
	    $(this.element).removeData("z_live_validation_instance");
	    return true;
	} else {
		return false;
	}
  },
  
  /**
   * get the to-be-validated fields
   */
  getFields: function() {
	var fields = [];
	$("input,select,textarea", this.element).each(function() {
		var field = $(this).data('z_live_validation');
		if (field) {
			fields.push(field);
		}
	});
	return fields;
  },

  asyncResult: function(Validation, isValid){
      if (isValid){
          var index = $.inArray(Validation, this.submitWaitForAsync);
          if (index >= 0){
              this.submitWaitForAsync.splice(index, 1);
              if (this.submitWaitForAsync.length == 0){
                  // All validations were successful, resubmit (and skip validations for once)
                  this.skipValidations = 1;
                  var formObj = this.element;
				  this.onValid.call(this);
                  setTimeout(function(){ $(formObj).submit(); }, 0);
              }
          }
      } else {
		  if (this.submitWaitForAsync.length > 0) {
			var formObj = this.element;
			this.onInvalid.call(this);
		  }
          this.submitWaitForAsync = new Array();
      }
  }
}// end of LiveValidationForm prototype




/*************************************** Validate class ****************************************/
/**
 * This class contains all the methods needed for doing the actual validation itself
 *
 * All methods are static so that they can be used outside the context of a form field
 * as they could be useful for validating stuff anywhere you want really
 *
 * All of them will return true if the validation is successful, but will raise a ValidationError if
 * they fail, so that this can be caught and the message explaining the error can be accessed ( as just 
 * returning false would leave you a bit in the dark as to why it failed )
 *
 * Can use validation methods alone and wrap in a try..catch statement yourself if you want to access the failure
 * message and handle the error, or use the Validate::now method if you just want true or false
 */

var Validate = {

    /**
     *  validates that the field has been filled in
     *
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation 
     *                            (DEFAULT: "Can't be empty!")
     */
    Presence: function(value, paramsObj){
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "*";
        if(value === '' || value === null || value === undefined){ 
            Validate.fail(message);
        }
        return true;
    },
    
    /**
     *  validates that the value is numeric, does not fall within a given range of numbers
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              notANumberMessage {String} - the message to show when the validation fails when value is not a number
     *                                (DEFAULT: "Must be a number!")
     *              notAnIntegerMessage {String} - the message to show when the validation fails when value is not an integer
     *                                (DEFAULT: "Must be a number!")
     *              wrongNumberMessage {String} - the message to show when the validation fails when is param is used
     *                                (DEFAULT: "Must be {is}!")
     *              tooLowMessage {String}    - the message to show when the validation fails when minimum param is used
     *                                (DEFAULT: "Must not be less than {minimum}!")
     *              tooHighMessage {String}   - the message to show when the validation fails when maximum param is used
     *                                (DEFAULT: "Must not be more than {maximum}!")
     *              is {Int}          - the length must be this long 
     *              minimum {Int}         - the minimum length allowed
     *              maximum {Int}         - the maximum length allowed
     *                         onlyInteger {Boolean} - if true will only allow integers to be valid
     *                                                             (DEFAULT: false)
     *
     *  NB. can be checked if it is within a range by specifying both a minimum and a maximum
     *  NB. will evaluate numbers represented in scientific form (ie 2e10) correctly as numbers       
     */
    Numericality: function(value, paramsObj){
        var suppliedValue = value;
        var value = Number(value);
        var paramsObj = paramsObj || {};
        var minimum = ((paramsObj.minimum) || (paramsObj.minimum == 0)) ? paramsObj.minimum : null;;
        var maximum = ((paramsObj.maximum) || (paramsObj.maximum == 0)) ? paramsObj.maximum : null;
        var is = ((paramsObj.is) || (paramsObj.is == 0)) ? paramsObj.is : null;
        var notANumberMessage = paramsObj.notANumberMessage || "Must be a number.";
        var notAnIntegerMessage = paramsObj.notAnIntegerMessage || "Must be an integer.";
        var wrongNumberMessage = paramsObj.wrongNumberMessage || "Must be " + is + ".";
        var tooLowMessage = paramsObj.tooLowMessage || "Must not be less than " + minimum + ".";
        var tooHighMessage = paramsObj.tooHighMessage || "Must not be more than " + maximum + ".";
        
        if (!isFinite(value)) 
            Validate.fail(notANumberMessage);
        if (paramsObj.onlyInteger && (/\.0+$|\.$/.test(String(suppliedValue))  || value != parseInt(value)) )
            Validate.fail(notAnIntegerMessage);
        switch(true){
            case (is !== null):
                if( value != Number(is) ) Validate.fail(wrongNumberMessage);
                break;
            case (minimum !== null && maximum !== null):
                Validate.Numericality(value, {tooLowMessage: tooLowMessage, minimum: minimum});
                Validate.Numericality(value, {tooHighMessage: tooHighMessage, maximum: maximum});
                break;
            case (minimum !== null):
                if( value < Number(minimum) ) Validate.fail(tooLowMessage);
                break;
            case (maximum !== null):
                if( value > Number(maximum) ) Validate.fail(tooHighMessage);
                break;
        }
        return true;
    },
    
    /**
     *  validates against a RegExp pattern
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Not valid!")
     *              pattern {RegExp}    - the regular expression pattern
     *                            (DEFAULT: /./)
     *             negate {Boolean} - if set to true, will validate true if the pattern is not matched
   *                           (DEFAULT: false)
     *
     *  NB. will return true for an empty string, to allow for non-required, empty fields to validate.
     *    If you do not want this to be the case then you must either add a LiveValidation.PRESENCE validation
     *    or build it into the regular expression pattern
     */
    Format: function(value, paramsObj){
      var value = String(value);
      var paramsObj = paramsObj || {};
      var message = paramsObj.failureMessage || "Not valid.";
      var pattern = paramsObj.pattern || /./;
      var negate = paramsObj.negate || false;
      if(!negate && !pattern.test(value)) Validate.fail(message); // normal
      if(negate && pattern.test(value)) Validate.fail(message); // negated
      return true;
    },
    
    /**
     *  validates that the field contains a valid email address
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Must be a number!" or "Must be an integer!")
     */
    Email: function(value, paramsObj){
      var paramsObj = paramsObj || {};
      var message = paramsObj.failureMessage || "Incorrect E-mail";
      value = $.trim(value);
      Validate.Format(value, { failureMessage: message, pattern: /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i } );
      return true;
    },
    
    /**
     *  validates the length of the value
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              wrongLengthMessage {String} - the message to show when the fails when is param is used
     *                                (DEFAULT: "Must be {is} characters long!")
     *              tooShortMessage {String}  - the message to show when the fails when minimum param is used
     *                                (DEFAULT: "Must not be less than {minimum} characters long!")
     *              tooLongMessage {String}   - the message to show when the fails when maximum param is used
     *                                (DEFAULT: "Must not be more than {maximum} characters long!")
     *              is {Int}          - the length must be this long 
     *              minimum {Int}         - the minimum length allowed
     *              maximum {Int}         - the maximum length allowed
     *
     *  NB. can be checked if it is within a range by specifying both a minimum and a maximum       
     */
    Length: function(value, paramsObj){
        var value = String(value);
        var paramsObj = paramsObj || {};
        var minimum = ((paramsObj.minimum) || (paramsObj.minimum == 0)) ? paramsObj.minimum : null;
        var maximum = ((paramsObj.maximum) || (paramsObj.maximum == 0)) ? paramsObj.maximum : null;
        var is = ((paramsObj.is) || (paramsObj.is == 0)) ? paramsObj.is : null;
        var wrongLengthMessage = paramsObj.wrongLengthMessage || "Must be " + is + " characters long.";
        var tooShortMessage = paramsObj.tooShortMessage || "Must not be less than " + minimum + " characters long.";
        var tooLongMessage = paramsObj.tooLongMessage || "Must not be more than " + maximum + " characters long.";
        switch(true){
            case (is !== null):
                if( value.length != Number(is) ) Validate.fail(wrongLengthMessage);
                break;
            case (minimum !== null && maximum !== null):
                Validate.Length(value, {tooShortMessage: tooShortMessage, minimum: minimum});
                Validate.Length(value, {tooLongMessage: tooLongMessage, maximum: maximum});
                break;
            case (minimum !== null):
                if( value.length < Number(minimum) ) Validate.fail(tooShortMessage);
                break;
            case (maximum !== null):
                if( value.length > Number(maximum) ) Validate.fail(tooLongMessage);
                break;
            default:
                throw new Error("Validate::Length - Length(s) to validate against must be provided");
        }
        return true;
    },
    
    /**
     *  validates that the value falls within a given set of values
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Must be included in the list!")
     *              within {Array}      - an array of values that the value should fall in 
     *                            (DEFAULT: []) 
     *              allowNull {Bool}    - if true, and a null value is passed in, validates as true
     *                            (DEFAULT: false)
     *             partialMatch {Bool}  - if true, will not only validate against the whole value to check but also if it is a substring of the value 
     *                            (DEFAULT: false)
     *             caseSensitive {Bool} - if false will compare strings case insensitively
     *                          (DEFAULT: true)
     *             negate {Bool}    - if true, will validate that the value is not within the given set of values
     *                            (DEFAULT: false)      
     */
    Inclusion: function(value, paramsObj){
      var paramsObj = paramsObj || {};
      var message = paramsObj.failureMessage || "Must be included in the list!";
      var caseSensitive = (paramsObj.caseSensitive === false) ? false : true;
      if(paramsObj.allowNull && value == null) return true;
      if(!paramsObj.allowNull && value == null) Validate.fail(message);
      var within = paramsObj.within || [];
      //if case insensitive, make all strings in the array lowercase, and the value too
      if(!caseSensitive){ 
        var lowerWithin = [];
        for(var j = 0, length = within.length; j < length; ++j){
          var item = within[j];
          if(typeof item == 'string') item = item.toLowerCase();
          lowerWithin.push(item);
        }
        within = lowerWithin;
        if(typeof value == 'string') value = value.toLowerCase();
      }
      var found = false;
      for(var i = 0, length = within.length; i < length; ++i){
        if(within[i] == value) found = true;
        if(paramsObj.partialMatch){ 
          if(value.indexOf(within[i]) != -1) found = true;
        }
      }
      if( (!paramsObj.negate && !found) || (paramsObj.negate && found) ) Validate.fail(message);
      return true;
    },
    
    /**
     *  validates that the value does not fall within a given set of values
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Must not be included in the list!")
     *              within {Array}      - an array of values that the value should not fall in 
     *                            (DEFAULT: [])
     *              allowNull {Bool}    - if true, and a null value is passed in, validates as true
     *                            (DEFAULT: false)
     *             partialMatch {Bool}  - if true, will not only validate against the whole value to check but also if it is a substring of the value 
     *                            (DEFAULT: false)
     *             caseSensitive {Bool} - if false will compare strings case insensitively
     *                          (DEFAULT: true)     
     */
    Exclusion: function(value, paramsObj){
      var paramsObj = paramsObj || {};
      paramsObj.failureMessage = paramsObj.failureMessage || "Must not be included in the list";
      paramsObj.negate = true;
      Validate.Inclusion(value, paramsObj);
      return true;
    },
    
    /**
     *  validates that the value matches that in another field
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Does not match!")
     *              match {String}      - id of the field that this one should match            
     */
    Confirmation: function(value, paramsObj){
        if(!paramsObj.match) 
            throw new Error("Validate::Confirmation - Error validating confirmation: Id of element to match must be provided");
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Does not match.";
        var match = paramsObj.match.nodeName ? paramsObj.match : document.getElementById(paramsObj.match);
        if(!match) 
            throw new Error("Validate::Confirmation - There is no reference with name of, or element with id of '" + paramsObj.match + "'");
        if(value != match.value){ 
          Validate.fail(message);
        }
        return true;
    },
    
    /**
     *  validates that the value is true (for use primarily in detemining if a checkbox has been checked)
     *  
     *  @var value {mixed} - value to be checked if true or not (usually a boolean from the checked value of a checkbox)
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation 
     *                            (DEFAULT: "Must be accepted!")
     */
    Acceptance: function(value, paramsObj){
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Must be accepted.";
        if(!value){ 
        Validate.fail(message);
        }
        return true;
    },
    
   /**
     *  validates against a custom function that returns true or false (or throws a Validate.Error) when passed the value
     *  
     *  @var value {mixed} - value to be checked
     *  @var paramsObj {Object} - parameters for this particular validation, see below for details
     *
     *  paramsObj properties:
     *              failureMessage {String} - the message to show when the field fails validation
     *                            (DEFAULT: "Not valid!")
     *              against {Function}      - a function that will take the value and object of arguments and return true or false 
     *                            (DEFAULT: function(){ return true; })
     *              args {Object}     - an object of named arguments that will be passed to the custom function so are accessible through this object within it 
     *                            (DEFAULT: {})
     */
    Custom: function(value, paramsObj, isSubmit, submitTrigger){
        var paramsObj = paramsObj || {};
        var against = paramsObj.against || function(){ return true; };
        var args = paramsObj.args || {};
        var message = paramsObj.failureMessage || "Not valid.";
        if (typeof against == "string") {
            var result = z_call_function_by_name(against, window, value, args, isSubmit, submitTrigger);
        } else {
            var result = against(value, args, isSubmit, submitTrigger);
        }
        if(!result) Validate.fail(message);
        return true;
    },


    /**
     * Performs a postback, delays the check till the postback is returned. till then a spinner is shown
     * next to the input element. 
     */
    Postback: function(value, paramsObj, isSubmit, submitTrigger) {
        var paramsObj = paramsObj || {};
        var against = paramsObj.against || function(){ return true; };
        var args = paramsObj.args || {};
        var message = paramsObj.failureMessage || "Not valid.";

        if (!against(value, args, isSubmit, submitTrigger)) {
            Validate.fail(message);
        } else if (paramsObj.z_postback) {
            // Perform the async postback
            extraParams = new Array();
            if (isSubmit) {
                extraParams.push({name: 'z_submitter', value: (submitTrigger && submitTrigger.name) ? submitTrigger.name : ''});
            }
            z_queue_postback(paramsObj.z_id, paramsObj.z_postback, extraParams); 
            return 'async';
        } else {
            return true;
        }
     },

  
    /**
     *  validates whatever it is you pass in, and handles the validation error for you so it gives a nice true or false reply
     *
     *  @var validationFunction {Function} - validation function to be used (ie Validation.validatePresence )
     *  @var value {mixed} - value to be checked if true or not (usually a boolean from the checked value of a checkbox)
     *  @var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
     */
    now: function(validationFunction, value, validationParamsObj){
        if(!validationFunction) throw new Error("Validate::now - Validation function must be provided!");
      var isValid = true;
        try{    
        validationFunction(value, validationParamsObj || {});
      } catch(error) {
        if(error instanceof Validate.Error){
          isValid =  false;
        }else{
          throw error;
        }
      }finally{ 
            return isValid 
        }
    },
    
    /**
     * shortcut for failing throwing a validation error
     *
     *  @var errorMessage {String} - message to display
     */
    fail: function(errorMessage){
            throw new Validate.Error(errorMessage);
    },
    
    Error: function(errorMessage){
      this.message = errorMessage;
      this.name = 'ValidationError';
    }

}