/*
*	Author:		Tim Alstadt
*	Company:		Eye-Site.nl Internet!
*	Date:			June, 5th 2009
*
*	This javascript file contains a function to perform several checks on html form fields to validate the data entered by the user.
*	
*	You can have form fields automaticly  checked by adding the following markers to the objects classnames:
*	check_notempty		Verifies that the form field is not empty.
*	check_email			Verifies that a valid email address is entered.
*	check_numeric			Verifies that a numeric value is entered.
*	check_url				Verifies that a valid url is entered (including http://)
*	
*	Additionally, add a title attribute to describe the form field. This title is used in the error message.
*
*	Example:
*		<input name="frm_email" type="text" class="check_notempty" title="email address">
*	This field will be checked for a valid email address.
*
*	To activate the validation routine, add the following attribute to your <form> element:
*		onsubmit='javascript: return checkForm(this);'
*	So that your complete form element looks like this:
*		<form name='frm_edit_details' action='?save' method='post' onsubmit='javascript: return checkForm(this);'>
*
*/

// Date check settings
var dtCh= "-";
var minYear=1900;
var maxYear=2100;

function IsNumeric (txt) {
	var ValidChars = "0123456789.";
	var IsNumber=true;
	var Char;

	for (y = 0; y < txt.length && IsNumber == true; y++) {
		Char = txt.charAt(y);
		if (ValidChars.indexOf(Char) == -1) {
			IsNumber = false;
		}
	}
	return IsNumber;
}

function elevenCheck (txt) {
	txt = txt.replace(/\D/, "");
	len = txt.length;
	var som=0;

	for (x=1; x<10; x++) {
		getal=txt.charAt(x-1);
		som+=getal*(10-x);
	} 

	if (som % 11==0 && len==9) {
		return true;
	} else {
		return false;
	}
	return false;
}

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++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray (n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function isDate (dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		return false
	}
	return true
}

function checkForm (form) {
	var emailcheck =/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
	var urlcheck = /(http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/
	var timecheck = /([0-1]\d|2[0-3]):([0-5]\d)/
	
	for (i = 0; i < form.elements.length; i++) {
		if (form.elements[i].className.search('check_email') != -1) {
			if (form.elements[i].value.length == 0 || !emailcheck.test(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' bevat geen geldig e-mailadres, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_url') != -1) {
			if (form.elements[i].value.length == 0 || !urlcheck.test(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' bevat geen geldig internetadres, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_numeric') != -1) {
			if (!IsNumeric(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' moet numeriek zijn, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				if(form.elements[i].tagName.toUpperCase() != 'SELECT') form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_notempty') != -1) {
			if (form.elements[i].value.length == 0) {
				window.alert('Het veld \'' + form.elements[i].title + '\' is niet ingevuld, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				if(form.elements[i].tagName.toUpperCase() != 'SELECT') form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_eleven') != -1) {
			if (!elevenCheck(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' bevat een ongeldige waarde (11 proef faalt), controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				if(form.elements[i].tagName.toUpperCase() != 'SELECT') form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_date') != -1) {
			if (!isDate(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' bevat een ongeldige datum, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				if(form.elements[i].tagName.toUpperCase() != 'SELECT') form.elements[i].select();
				return false;
			}
		}

		if (form.elements[i].className.search('check_time') != -1) {
			if (form.elements[i].value.length > 0 && !timecheck.test(form.elements[i].value)) {
				window.alert('Het veld \'' + form.elements[i].title + '\' bevat een ongeldige tijd, controleer dit en probeer het nogmaals.');
				form.elements[i].focus();
				if(form.elements[i].tagName.toUpperCase() != 'SELECT') form.elements[i].select();
				return false;
			}
		}
	}

	return true;
}