CautemocSg/ng-ip-address

(function() {
    'use strict';
    angular
        .module('ng-ip-address', [])
        .directive('ngIpAddress', ngIpAddress);

    function ngIpAddress() {
        return {
            restrict: 'A',
            require: '?ngModel',
            link: function(scope, element, attrs, ngModelCtrl) {
                if (!ngModelCtrl) {
                    return;
                }

                // Initialize regex...
                // Match leading zero
                var regexLeadingZero = new RegExp('^0', 'g');
                // Match leading period
                var regexLeadingPeriod = new RegExp('^\\.', 'g');
                // Match duplicate period
                var regexDupePeriods = new RegExp('\\.\\.+', 'g');

                // Initialize caret position tracker
                var curPos = 0;

                // Initialize ctrl/cmd tracker
                var ctrlDown = false;

                // Attach key evaluators to the element keydown and keyup events to check
                // for when ctrl/cmd is being held down
                element.bind('keydown', evalIfCtrlDown);
                element.bind('keyup', evalIfCtrlUp);

                // Attach key evaluator to the element keypress event
                element.bind('keypress', evalKeyPress);

                // Attach input evaluator to the input model parsers
                ngModelCtrl.$parsers.push(evalInput);

                function evalIfCtrlDown(event) {
                    // If the character code represents ctrl/cmd...
                    if (event.which === 17 || event.which === 91) {
                        // Toggle the tracker
                        ctrlDown = true;
                    }
                }

                function evalIfCtrlUp(event) {
                    // If the character code represents ctrl/cmd...
                    if (event.which === 17 || event.which === 91) {
                        // Toggle the tracker
                        ctrlDown = false;
                    }
                }

                function evalKeyPress(event) {
                    // If the character code is not allowed...
                    if ((event.which < 46 && event.which !== 0 && event.which !== 8 && event.which !== 13)
                        || event.which === 47
                        || event.which > 57 && !(ctrlDown && (event.which === 99 || event.which === 118 || event.which === 120))) {
                        // Stop key press from propagating
                        event.preventDefault();
                    }
                }

                function evalInput(val) {
                    // If val is falsy (undefined, empty string, etc)...
                    if (!val) {
                        // Set the field validity to true since it should be the responsibility of 'required' to stop blank entries
                        ngModelCtrl.$setValidity('ipAddress', true);
                        // Return value
                        return val;
                    }

                    var newVal = val;

                    // Set caret position tracker
                    curPos = element[0].selectionStart;

                    // Initialize validation result tracker
                    var validationResult = true;

                    // Remove leading period
                    newVal = newVal.replace(regexLeadingPeriod, '');

                    // Remove any duplicate periods
                    newVal = newVal.replace(regexDupePeriods, '.');

                    // Break the IP address into segments
                    var valArray = newVal.split('.');
                    // Eval length to be used later
                    var valArrayLength = valArray.length;

                    // If there are less than four IP segments...
                    if (valArrayLength < 4) {
                        // Set validity tracker to false
                        validationResult = false;
                    }
                    // Otherwise, if there are more than four IP segments...
                    else if (valArrayLength > 4) {
                        // Enforce 4 segment limit
                        valArray.length = 4;
                        // Update array length
                        valArrayLength = 4;
                    }

                    // For each segment...
                    for (var i = 0; i < valArrayLength; i++) {
                        // Eval array value to be used later so the array isn't getting accessed so often
                        var arrayVal = valArray[i];
                        // If the ip segment value is longer than one digit...
                        if (arrayVal.length > 1) {
                            // Delete leading zeroes and any number after the third
                            arrayVal = arrayVal.replace(regexLeadingZero, '').substring(0, 3);
                            // If the value is greater than 255...
                            if (!isNumeric(arrayVal) || arrayVal > 255) {
                                // Set validity tracker to false
                                validationResult = false;
                            }
                        }
                        // Otherwise, check if the value is empty...
                        else if (!arrayVal) {
                            // Set validity tracker to false
                            validationResult = false;
                        }
                        // Set the final value back to the segment
                        valArray[i] = arrayVal;
                    }

                    // Reassemble the segments
                    newVal = valArray.join('.');

                    // Set validity of field (will be displayed as class 'ng-valid-ip-address' or 'ng-invalid-ip-address')
                    ngModelCtrl.$setValidity('ipAddress', validationResult);

                    // Update the view if the new values differs from the entered value
                    if (newVal !== val) {
                        ngModelCtrl.$setViewValue(newVal);
                        ngModelCtrl.$render();

                        // Set the caret position back to where it was prior to re-render
                        element[0].setSelectionRange(curPos, curPos);

                        // Return new value
                        return newVal;
                    }

                    // Return value
                    return val;
                }

                // Determines if a passed value is numeric
                function isNumeric(n) {
                    return !isNaN(parseFloat(n)) && isFinite(n);
                }
            }
        };
    }
}());