/*

Generic Form Validation.
tboland@gmail.com
http://www.techtoolblog.com
License: Free To Use, If Modified/Added
please send updated source to tboland@gmail.com
 
To Validate a Form Element Add the Custom Attribute:
validate="VALIDATEHOW"

Your Current Options Are:
"not_empty"
"integer"
"number" - decimal allowed
"email"
"phone" - includes international phone numbers

Multiple Validation uses the following syntax:
validate="not_empty|integer"

To Add a Message Add the Custom Attribute:
msg="Name is a required field" 

By Default the Messages are shown next to the form element.
To Show Alert Boxes add a Custom Attribute in the form tag (show_alert):
<form action="mypage.aspx" show_alert="1" onSubmit="return Validate(this);">

Examples:
<html>
<head>
<script language="JavaScript" src="gfv.js" type="text/javascript"></script>
</head>
<body>
<form action="mypage.php" show_alert="1" onSubmit="return Validate(this);">
First Name <input type="Text" name="FirstName" maxlength="25" validate="not_empty" msg="First Name is Required" /><br/>
Email <input type="text" name="Email" maxlength="25" validate="email" msg="Email is Required" /><br/>
<input type="submit" value="Go">
</form></body></html>

ADVANCED USERS:
Add Your Own Function Calls to the validate attribute.
It Must return true or false
example:
<input type="text" name="Age" validate="ValidateAge" />
*/
function Validate(objForm) {
    
    
    var arrValidated=new Array();
    
    for (var i=0; i<objForm.elements.length; i++) {
        var element=objForm.elements[i];
        var elName=element.name;
        if ((!elName)||(elName.length == 0)||(arrValidated[elName]))
            continue;
        arrValidated[elName] = true;
        var validationType = element.getAttribute("validate");
        if ((!validationType)||(validationType.length == 0))
            continue;
        var strMessages=element.getAttribute("msg");
        if (!strMessages)
            strMessages = "";
        var arrMessages = strMessages.split("|");
        var arrValidationTypes = validationType.split("|");     
        for (var j=0; j<arrValidationTypes.length; j++) {
            var curValidationType = arrValidationTypes[j];
            var blnValid=true;
            switch (curValidationType) {
                case "not_empty":
                    blnValid = ValidateNotEmpty(element);
                    break;
                case "integer":
                    blnValid = ValidateInteger(element);
                    break;
                case "number":
                    blnValid = ValidateNumber(element);
                    break;
                case "email":
                    blnValid = ValidateEmail(element);
                    break;
                case "phone":
                    blnValid = ValidatePhone(element);
                    break;
                default:
                    try {
                        blnValid = eval(curValidationType+"(element)");
                    }
                    catch (ex) {
                        blnValid = true;
                    }
            }
            if (blnValid == false) {
                var message="invalid value for "+element.name;
                if ((j < arrMessages.length)&&(arrMessages[j].length > 0))
                    message = arrMessages[j];
                InsertError(element, message);
                if ((typeof element.focus == "function")||(element.focus)) {
                    element.focus();
                }
                return false;
            }
            else
                ClearError(element);
        }
        
    }
    
    return true;
}

//Empty Validation
function ValidateNotEmpty(objElement) {
    var strValue = GetElementValue(objElement);
    var blnResult = true;
    if(allTrim(strValue) == "") //check for nothing
    {
    blnResult = false;
    }
    return blnResult;
}

//Integer Validation
function  ValidateInteger(objElement)
   //  check for valid numeric strings  
   {
   var strString = GetElementValue(objElement);
   var strValidChars = "0123456789";
   var strChar;
   var blnResult = true;
  
   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
   }

//Number Validation
function  ValidateNumber(objElement)
   //  check for valid numeric strings  
   {
   var strString = GetElementValue(objElement);
   var strValidChars = ".0123456789"; //decimal ok
   var strChar;
   var blnResult = true;

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
   }
   
   //Email Validation
   function ValidateEmail(objElement) {
    //  Will check for @, period after @ and text in between
    var strValue = GetElementValue(objElement);
    var in_space = strValue.indexOf(" ");
    if (in_space != -1)
    { return false;  }

    var len = strValue.length;
    var alpha = strValue.indexOf("@");
    var last_alpha = strValue.lastIndexOf("@");

    if (alpha != last_alpha)
     { return false; }

    // No @, in first position, or name too short
    if (alpha == -1 || alpha == 0 || len<6 )
     { return false; }

    var last_p = strValue.lastIndexOf(".");
            // Be sure period at least two spaces after @, but not last char.
            
    if (last_p - alpha < 2 || last_p == (len - 1) )
        { return false; }
    }
    

    
    //Valid PhoneNumber
    function ValidatePhone(objElement){
    // non-digit characters which are allowed in phone numbers
    var phoneNumberDelimiters = "()- ";
    // characters which are allowed in international phone numbers
    // (a leading + is OK)
    var validWorldPhoneChars = phoneNumberDelimiters + "+";
    // Minimum no of digits in an international phone no.
    var minDigitsInIPhoneNumber = 9;
    
    var strValue = GetElementValue(objElement);
    s=stripCharsInBag(strValue,validWorldPhoneChars);
    return (ValidateInteger(s) && s.length >= minDigitsInIPhoneNumber);
    }


function GetElementValue(objElement) {
    var result="";
    switch (objElement.type) {
        case "text":
        case "hidden":
        case "textarea":
        case "password":
            result = objElement.value;
            break;
        case "select-one":
        case "select":
            if (objElement.selectedIndex >= 0)
                result = objElement.options[objElement.selectedIndex].value;
            break;
        case "radio":
        case "checkbox":
            for (var i=0; i<objElement.form.elements.length; i++) {
                if (objElement.form.elements[i].name == objElement.name) {
                    if (objElement.form.elements[i].checked)
                        result += objElement.form.elements[i].value+",";
                }
            }
            break;
    }
    return result;
}

function InsertError(element, strMessage) {
    if ((element.form.getAttribute("show_alert")) && (element.form.getAttribute("show_alert") != "0")) {
        alert(strMessage);
        return;
    }
    
    var strSpanID = element.name+"_val_error";
    var objSpan = document.getElementById(strSpanID);
    if (!objSpan) {
        if ((element.type == "radio")||(element.type == "checkbox")) {
            for (var i=0; i<element.form.elements.length; i++) {
                if (element.form.elements[i].name == element.name) {
                    element = element.form.elements[i];
                }
            }
        }
        objSpan = document.createElement("span");
        objSpan.id = strSpanID;
        objSpan.className = "validation_error";
        var nodeAfter=0;
        var nodeParent = element.parentNode;
        for (var i=0; i<nodeParent.childNodes.length; i++) {
            if (nodeParent.childNodes[i] == element) {
                if (i < (nodeParent.childNodes.length-1))
                    nodeAfter = nodeParent.childNodes[i+1];
                break;
            }
        }
        if ((!nodeAfter)&&(nodeParent.parentNode)) {
            nodeParent = nodeParent.parentNode;
            for (var i=0; i<nodeParent.childNodes.length; i++) {
                if (nodeParent.childNodes[i] == element.parentNode) {
                    if (i < (nodeParent.childNodes.length-1))
                        nodeAfter = nodeParent.childNodes[i+1];
                    break;
                }
            }
        }
        if (nodeAfter)
            nodeParent.insertBefore(objSpan, nodeAfter);
        else
            document.body.appendChild(objSpan);
    }
    objSpan.innerHTML = strMessage;
}

function ClearError(element) {
    var strSpanID = element.name+"_val_error";
    var objSpan = document.getElementById(strSpanID);
    if (objSpan) {
        objSpan.innerHTML = "";
    }
}

function allTrim(cValue){
 var lDone=false;
 while (lDone==false){
  if (cValue.length==0) {return cValue;}
  if (cValue.indexOf(' ')==0){cValue=cValue.substring(1);lDone=false; continue;}
  else {lDone=true;}
  if (cValue.lastIndexOf(' ')==cValue.length-1){cValue=cValue.substring(0, cValue.length-1);lDone=false;continue;}
  else {lDone=true;}
 }
 return cValue;
}

function stripCharsInBag(s, bag)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}
