Timezone detection: Client implementation

refs #6078

library/Icinga/Web/JavaScript.php

@@ -21,6 +21,7 @@ class JavaScript
         'js/icinga/events.js',
         'js/icinga/history.js',
         'js/icinga/module.js',
+        'js/icinga/timezone.js',
     );
 
     protected static $vendorFiles = array(

public/js/icinga.js

@@ -82,6 +82,7 @@
                 return false;
             }
 
+            this.timezone   = new Icinga.Timezone();
             this.utils      = new Icinga.Utils(this);
             this.logger     = new Icinga.Logger(this);
             this.timer      = new Icinga.Timer(this);
@@ -90,6 +91,7 @@
             this.events     = new Icinga.Events(this);
             this.history    = new Icinga.History(this);
 
+            this.timezone.initialize();
             this.timer.initialize();
             this.events.initialize();
             this.history.initialize();
@@ -147,6 +149,7 @@
                 module.destroy();
             });
 
+            this.timezone.destroy();
             this.timer.destroy();
             this.events.destroy();
             this.loader.destroy();

public/js/icinga/timezone.js

@@ -0,0 +1,117 @@
+(function(Icinga, $) {
+
+    'use strict';
+
+    /**
+     * Get the maximum timezone offset
+     *
+     * @returns {Number}
+     */
+    Date.prototype.getStdTimezoneOffset = function() {
+        if (Date.maxTimezoneOffset !== undefined) {
+            return Date.maxTimezoneOffset;
+        }
+
+        var year = new Date().getYear();
+        var previousOffset;
+
+        for (var i=0; i<12; i++) {
+            var d = new Date(year, i, 1);
+            if (previousOffset !== undefined) {
+                previousOffset = Math.max(previousOffset, d.getTimezoneOffset());
+            } else {
+                previousOffset = d.getTimezoneOffset();
+            }
+        }
+
+        Date.maxTimezoneOffset = previousOffset;
+
+        return Date.maxTimezoneOffset;
+    };
+
+    /**
+     * Test for daylight saving time zone
+     * 
+     * @returns {boolean}
+     */
+    Date.prototype.isDst = function() {
+        return (this.getStdTimezoneOffset() === this.getTimezoneOffset()) ? false : true;
+    };
+
+    /**
+     * Write timezone information into a cookie
+     *
+     * @constructor
+     */
+    Icinga.Timezone = function() {
+        this.cookieName = 'icingaweb2-tzo';
+    };
+
+    Icinga.Timezone.prototype = {
+        /**
+         * Initialize interface method
+         */
+        initialize: function () {
+            this.writeTimezone();
+        },
+
+        destroy: function() {
+            // PASS
+        },
+
+        /**
+         * Write timezone information into cookie
+         */
+        writeTimezone: function() {
+            var date = new Date();
+            var timezoneOffset = (date.getTimezoneOffset()*60) * -1;
+            var dst = date.isDst();
+
+            if (this.readCookie(this.cookieName)) {
+                return;
+            }
+
+            this.writeCookie(this.cookieName, timezoneOffset + ',' + dst);
+        },
+
+        /**
+         * Write cookie data
+         *
+         * @param {String} name
+         * @param {String} value
+         * @param {Number} days
+         */
+        writeCookie: function(name, value, days) {
+            var expires = '';
+
+            if (days) {
+                var date = new Date();
+                date.setTime(date.getTime()+(days*24*60*60*1000));
+                var expires = '; expires=' + date.toGMTString();
+            }
+            document.cookie = name + '=' + value + expires + '; path=/';
+        },
+
+        /**
+         * Read cookie data
+         *
+         * @param {String} name
+         * @returns {*}
+         */
+        readCookie: function(name) {
+            var nameEq = name + '=';
+            var ca = document.cookie.split(';');
+            for(var i=0;i < ca.length;i++) {
+                var c = ca[i];
+                while (c.charAt(0)==' ') {
+                    c = c.substring(1,c.length);
+                }
+                if (c.indexOf(nameEq) == 0) {
+                    return c.substring(nameEq.length,c.length);
+                }
+            }
+            return null;
+        }
+    };
+
+})(Icinga, jQuery);