Validating a HTML Form

@TJ111Jun 19.2007 — #Try something like this. It's what I use before anyone submits a form. (Yeah I know I'm lazy). [url=http://javascript.internet.com/forms/regexp-validation.html]Source[/url]
<i>
 </i>// returns true if the string is empty
 function isEmpty(str){
 return (str == null) || (str.length == 0);
 }
 // returns true if the string is a valid email
 function isEmail(str){
 if(isEmpty(str)) return false;
 var re = /^[^s()&lt;&gt;@,;:/]+@w[w.-]+.[a-z]{2,}$/i
 return re.test(str);
 }
 // returns true if the string only contains characters A-Z or a-z
 function isAlpha(str){
 var re = /[^a-zA-Z]/g
 if (re.test(str)) return false;
 return true;
 }
 // returns true if the string only contains characters 0-9
 function isNumeric(str){
 var re = /[D]/g
 if (re.test(str)) return false;
 return true;
 }
 // returns true if the string only contains characters A-Z, a-z or 0-9
 function isAlphaNumeric(str){
 var re = /[^a-zA-Z0-9]/g
 if (re.test(str)) return false;
 return true;
 }
 // returns true if the string's length equals "len"
 function isLength(str, len){
 return str.length == len;
 }
 // returns true if the string's length is between "min" and "max"
 function isLengthBetween(str, min, max){
 return (str.length &gt;= min)&amp;&amp;(str.length &lt;= max);
 }
 // returns true if the string is a US phone number formatted as...
 // (000)000-0000, (000) 000-0000, 000-000-0000, 000.000.0000, 000 000 0000, 0000000000
 function isPhoneNumber(str){
 var re = /^(?[2-9]d{2}[).-]?s?d{3}[s.-]?d{4}$/
 return re.test(str);
 }
 // returns true if the string is a valid date formatted as...
 // mm dd yyyy, mm/dd/yyyy, mm.dd.yyyy, mm-dd-yyyy
 function isDate(str){
 var re = /^(d{1,2})[s./-](d{1,2})[s./-](d{4})$/
 if (!re.test(str)) return false;
 var result = str.match(re);
 var m = parseInt(result[1]);
 var d = parseInt(result[2]);
 var y = parseInt(result[3]);
 if(m &lt; 1 || m &gt; 12 || y &lt; 1900 || y &gt; 2100) return false;
 if(m == 2){
 var days = ((y % 4) == 0) ? 29 : 28;
 }else if(m == 4 || m == 6 || m == 9 || m == 11){
 var days = 30;
 }else{
 var days = 31;
 }
 return (d &gt;= 1 &amp;&amp; d &lt;= days);
 }
 // returns true if "str1" is the same as the "str2"
 function isMatch(str1, str2){
 return str1 == str2;
 }
 // returns true if the string contains only whitespace
 // cannot check a password type input for whitespace
 function isWhitespace(str){ // NOT USED IN FORM VALIDATION
 var re = /[S]/g
 if (re.test(str)) return false;
 return true;
 }
 // removes any whitespace from the string and returns the result
 // the value of "replacement" will be used to replace the whitespace (optional)
 function stripWhitespace(str, replacement){// NOT USED IN FORM VALIDATION
 if (replacement == null) replacement = '';
 var result = str;
 var re = /s/g
 if(str.search(re) != -1){
 result = str.replace(re, replacement);
 }
 return result;
 }
 // validate the form
 function validateForm(f, preCheck){
 var errors = '';
 if(preCheck != null) errors += preCheck;
 var i,e,t,n,v;
 for(i=0; i &lt; f.elements.length; i++){
 e = f.elements[i];
 if(e.optional) continue;
 t = e.type;
 n = e.name;
 v = e.value;
 if(t == 'text' || t == 'password' || t == 'textarea'){
 if(isEmpty(v)){
 errors += n+' cannot be empty.n'; continue;
 }
 if(v == e.defaultValue){
 errors += n+' cannot use the default value.n'; continue;
 }
 if(e.isAlpha){
 if(!isAlpha(v)){
 errors += n+' can only contain characters A-Z a-z.n'; continue;
 }
 }
 if(e.isNumeric){
 if(!isNumeric(v)){
 errors += n+' can only contain characters 0-9.n'; continue;
 }
 }
 if(e.isAlphaNumeric){
 if(!isAlphaNumeric(v)){
 errors += n+' can only contain characters A-Z a-z 0-9.n'; continue;
 }
 }
 if(e.isEmail){
 if(!isEmail(v)){
 errors += v+' is not a valid email.n'; continue;
 }
 }
 if(e.isLength != null){
 var len = e.isLength;
 if(!isLength(v,len)){
 errors += n+' must contain only '+len+' characters.n'; continue;
 }
 }
 if(e.isLengthBetween != null){
 var min = e.isLengthBetween[0];
 var max = e.isLengthBetween[1];
 if(!isLengthBetween(v,min,max)){
 errors += n+' cannot contain less than '+min+' or more than '+max+' characters.n'; continue;
 }
 }
 if(e.isPhoneNumber){
 if(!isPhoneNumber(v)){
 errors += v+' is not a valid US phone number.n'; continue;
 }
 }
 if(e.isDate){
 if(!isDate(v)){
 errors += v+' is not a valid date.n'; continue;
 }
 }
 if(e.isMatch != null){
 if(!isMatch(v, e.isMatch)){
 errors += n+' does not match.n'; continue;
 }
 }
 }
 if(t.indexOf('select') != -1){
 if(isEmpty(e.options[e.selectedIndex].value)){
 errors += n+' needs an option selected.n'; continue;
 }
 }
 if(t == 'file'){
 if(isEmpty(v)){
 errors += n+' needs a file to upload.n'; continue;
 }
 }
 }
 if(errors != '') alert(errors);
 return errors == '';
 }
 
 /*
 The following elements are not validated...
 
 button   type="button"
 checkbox type="checkbox"
 hidden   type="hidden"
 radio    type="radio"
 reset    type="reset"
 submit   type="submit"
 
 All elements are assumed required and will only be validated for an
 empty value or defaultValue unless specified by the following properties.
 
 isEmail = true;          // valid email address
 isAlpha = true;          // A-Z a-z characters only
 isNumeric = true;        // 0-9 characters only
 isAlphaNumeric = true;   // A-Z a-z 0-9 characters only
 isLength = number;       // must be exact length
 isLengthBetween = array; // [lowNumber, highNumber] must be between lowNumber and highNumber
 isPhoneNumber = true;    // valid US phone number. See "isPhoneNumber()" comments for the formatting rules
 isDate = true;           // valid date. See "isDate()" comments for the formatting rules
 isMatch = string;        // must match string
 optional = true;         // element will not be validated
 */
 
 // ||||||||||||||||||||||||||||||||||||||||||||||||||
 // --------------------------------------------------
 // ||||||||||||||||||||||||||||||||||||||||||||||||||
 
 // All of the previous JavaScript is coded to process
 // any form and should be kept in an external file if
 // multiple forms are being processed.
 
 // This function configures the previous
 // form validation code for this form.
 function configureValidation(f){
 f.firstname.isAlphaNumeric = true;
 f.lastname.isAlphaNumeric = true;
 f.email.isEmail = true;
 f.phone.isPhoneNumber = true;
 f.birthday.isDate = true;
 f.password1.isLengthBetween = [4,255];
 f.password2.isMatch = f.password1.value;
 f.comments.optional = true;
 var preCheck = (!f.infohtml.checked &amp;&amp; !f.infocss.checked &amp;&amp; !f.infojs.checked) ? 'select at least one checkbox.n' : null;
 return validateForm(f, preCheck);
 }
Validating a HTML Form

3 Comments(s) _↴

Also in #JavaScript _↴

Success!

Social

Version

Validating a HTML Form

3 Comments(s) ↴

Also in #JavaScript ↴

Success!

The web is an endless sea of information. Don't miss the boat... Subscribe!

Social

Version

3 Comments(s) _↴

Also in #JavaScript _↴
