// JavaScript Document // create object function formValidator() { // set up array to hold error messages this.errorList = new Array; // set up object methods this.isEmpty = isEmpty; this.isNumber = isNumber; this.isAlphabetic = isAlphabetic; this.isAlphaNumeric = isAlphaNumeric; this.isWithinRange = isWithinRange; this.isEmailAddress = isEmailAddress; this.isChecked = isChecked; this.raiseError = raiseError; this.numErrors = numErrors; this.displayErrors = displayErrors; } /* * isEmpty() - check whether the specified form variable is empty; * isNumber() - check whether the specified form variable is a number; * isAlphabetic() - check whether the specified form variable contains alphabetic data; * isAlphaNumeric() - check whether the specified form variable contains alphanumeric data; * isWithinRange() - check whether the specified form variable contains a value within the specified numeric range; * isEmailAddress() - check whether the specified form variable contains a valid email address; * raiseError() - add an error message to the error stack; * displayErrors() - display the list of error messages as alert boxes; * numErrors() - return the number of error messages generated so far. */ // check to see if input is whitespace only or empty function isEmpty(val) { // if (val.match(/\s+$/) || val == "") { // if (val.match(/^[ \t]+|[ \t]+$/) || val == "") { if (val.match(/\s[^ ]\b/) || val == "") { return true; } else { return false; } } // check to see if input is number function isNumber(val) { if (isNaN(val)) { return false; } else { return true; } } // check to see if value is within min and max function isWithinRange(val, min, max) { if (val >= min && val <= max){ return true; } else { return false; } } // check to see if form value is checked /* Note the difference between this method, and the ones that preceded it. Previous object methods have been written to accept a form value as argument; this one accepts an object, representing the checkbox element, as argument. */ function isChecked(obj) { if (obj.checked) { return true; } else { return false; } } // check to see if input is alphabetic function isAlphabetic(val) { if (val.match(/^[a-zA-Z]+$/)) { return true; } else { return false; } } // check to see if input is alphanumeric function isAlphaNumeric(val) { if (val.match(/^[a-zA-Z0-9]+$/)) { return true; } else { return false; } } // check to see if input is a valid email address function isEmailAddress(val) { if (val.match(/^([a-zA-Z0-9])+([.a-zA-Z0-9_-])*@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-]+)+/)) { /* \b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b */ return true; } else { return false; } } // add an error to error list function raiseError(msg) { this.errorList[this.errorList.length] = msg; } // return number of errors in error array function numErrors() { return this.errorList.length; } // display all errors // iterate through error array and print each item function displayErrors() { for (x=0; x