1 // Copyright (C) 2011, John 'Warthog9' Hawley <warthog9@eaglescrag.net>
2 // 2011, Jakub Narebski <jnareb@gmail.com>
5 * @fileOverview Manipulate dates in gitweb output, adjusting timezone
6 * @license GPLv2 or later
10 * Get common timezone, add UI for changing timezones, and adjust
11 * dates to use requested common timezone.
13 * This function is called during onload event (added to window.onload).
15 * @param {String} tzDefault: default timezone, if there is no cookie
16 * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
17 * @param {String} tzCookieInfo.name: name of cookie to store timezone
18 * @param {String} tzClassName: denotes elements with date to be adjusted
20 function onloadTZSetup(tzDefault, tzCookieInfo, tzClassName) {
21 var tzCookieTZ = getCookie(tzCookieInfo.name, tzCookieInfo);
25 // set timezone to value saved in a cookie
27 // refresh cookie, so its expiration counts from last use of gitweb
28 setCookie(tzCookieInfo.name, tzCookieTZ, tzCookieInfo);
31 // add UI for changing timezone
32 addChangeTZ(tz, tzCookieInfo, tzClassName);
34 // server-side of gitweb produces datetime in UTC,
35 // so if tz is 'utc' there is no need for changes
36 var nochange = tz === 'utc';
38 // adjust dates to use specified common timezone
39 fixDatetimeTZ(tz, tzClassName, nochange);
43 /* ...................................................................... */
44 /* Changing dates to use requested timezone */
47 * Replace RFC-2822 dates contained in SPAN elements with tzClassName
48 * CSS class with equivalent dates in given timezone.
50 * @param {String} tz: numeric timezone in '(-|+)HHMM' format, or 'utc', or 'local'
51 * @param {String} tzClassName: specifies elements to be changed
52 * @param {Boolean} nochange: markup for timezone change, but don't change it
54 function fixDatetimeTZ(tz, tzClassName, nochange) {
55 // sanity check, method should be ensured by common-lib.js
56 if (!document.getElementsByClassName) {
60 // NOTE: result of getElementsByClassName should probably be cached
61 var classesFound = document.getElementsByClassName(tzClassName, "span");
62 for (var i = 0, len = classesFound.length; i < len; i++) {
63 var curElement = classesFound[i];
65 curElement.title = 'Click to change timezone';
67 // we use *.firstChild.data (W3C DOM) instead of *.innerHTML
68 // as the latter doesn't always work everywhere in every browser
69 var epoch = parseRFC2822Date(curElement.firstChild.data);
70 var adjusted = formatDateRFC2882(epoch, tz);
72 curElement.firstChild.data = adjusted;
78 /* ...................................................................... */
79 /* Adding triggers, generating timezone menu, displaying and hiding */
82 * Adds triggers for UI to change common timezone used for dates in
83 * gitweb output: it marks up and/or creates item to click to invoke
84 * timezone change UI, creates timezone UI fragment to be attached,
85 * and installs appropriate onclick trigger (via event delegation).
87 * @param {String} tzSelected: pre-selected timezone,
88 * 'utc' or 'local' or '(-|+)HHMM'
89 * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
90 * @param {String} tzClassName: specifies elements to install trigger
92 function addChangeTZ(tzSelected, tzCookieInfo, tzClassName) {
93 // make link to timezone UI discoverable
94 addCssRule('.'+tzClassName + ':hover',
95 'text-decoration: underline; cursor: help;');
97 // create form for selecting timezone (to be saved in a cookie)
98 var tzSelectFragment = document.createDocumentFragment();
99 tzSelectFragment = createChangeTZForm(tzSelectFragment,
100 tzSelected, tzCookieInfo, tzClassName);
102 // event delegation handler for timezone selection UI (clicking on entry)
103 // see http://www.nczonline.net/blog/2009/06/30/event-delegation-in-javascript/
104 // assumes that there is no existing document.onclick handler
105 document.onclick = function onclickHandler(event) {
106 //IE doesn't pass in the event object
107 event = event || window.event;
109 //IE uses srcElement as the target
110 var target = event.target || event.srcElement;
112 switch (target.className) {
114 // don't display timezone menu if it is already displayed
115 if (tzSelectFragment.childNodes.length > 0) {
116 displayChangeTZForm(target, tzSelectFragment);
124 * Create DocumentFragment with UI for changing common timezone in
125 * which dates are shown in.
127 * @param {DocumentFragment} documentFragment: where attach UI
128 * @param {String} tzSelected: default (pre-selected) timezone
129 * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
130 * @returns {DocumentFragment}
132 function createChangeTZForm(documentFragment, tzSelected, tzCookieInfo, tzClassName) {
133 var div = document.createElement("div");
134 div.className = 'popup';
136 /* '<div class="close-button" title="(click on this box to close)">X</div>' */
137 var closeButton = document.createElement('div');
138 closeButton.className = 'close-button';
139 closeButton.title = '(click on this box to close)';
140 closeButton.appendChild(document.createTextNode('X'));
141 closeButton.onclick = closeTZFormHandler(documentFragment, tzClassName);
142 div.appendChild(closeButton);
144 /* 'Select timezone: <br clear="all">' */
145 div.appendChild(document.createTextNode('Select timezone: '));
146 var br = document.createElement('br');
150 /* '<select name="tzoffset">
152 * <option value="-0700">UTC-07:00</option>
153 * <option value="-0600">UTC-06:00</option>
156 var select = document.createElement("select");
157 select.name = "tzoffset";
158 //select.style.clear = 'all';
159 select.appendChild(generateTZOptions(tzSelected));
160 select.onchange = selectTZHandler(documentFragment, tzCookieInfo, tzClassName);
161 div.appendChild(select);
163 documentFragment.appendChild(div);
165 return documentFragment;
170 * Hide (remove from DOM) timezone change UI, ensuring that it is not
171 * garbage collected and that it can be re-enabled later.
173 * @param {DocumentFragment} documentFragment: contains detached UI
174 * @param {HTMLSelectElement} target: select element inside of UI
175 * @param {String} tzClassName: specifies element where UI was installed
176 * @returns {DocumentFragment} documentFragment
178 function removeChangeTZForm(documentFragment, target, tzClassName) {
179 // find containing element, where we appended timezone selection UI
180 // `target' is somewhere inside timezone menu
181 var container = target.parentNode, popup = target;
183 container.className !== tzClassName) {
185 container = container.parentNode;
187 // safety check if we found correct container,
188 // and if it isn't deleted already
189 if (!container || !popup ||
190 container.className !== tzClassName ||
191 popup.className !== 'popup') {
192 return documentFragment;
195 // timezone selection UI was appended as last child
196 // see also displayChangeTZForm function
197 var removed = popup.parentNode.removeChild(popup);
198 if (documentFragment.firstChild !== removed) { // the only child
199 // re-append it so it would be available for next time
200 documentFragment.appendChild(removed);
202 // all of inline style was added by this script
203 // it is not really needed to remove it, but it is a good practice
204 container.removeAttribute('style');
206 return documentFragment;
211 * Display UI for changing common timezone for dates in gitweb output.
212 * To be used from 'onclick' event handler.
214 * @param {HTMLElement} target: where to install/display UI
215 * @param {DocumentFragment} tzSelectFragment: timezone selection UI
217 function displayChangeTZForm(target, tzSelectFragment) {
218 // for absolute positioning to be related to target element
219 target.style.position = 'relative';
220 target.style.display = 'inline-block';
222 // show/display UI for changing timezone
223 target.appendChild(tzSelectFragment);
227 /* ...................................................................... */
228 /* List of timezones for timezone selection menu */
231 * Generate list of timezones for creating timezone select UI
233 * @returns {Object[]} list of e.g. { value: '+0100', descr: 'GMT+01:00' }
235 function generateTZList() {
237 { value: "utc", descr: "UTC/GMT"},
238 { value: "local", descr: "Local (per browser)"}
241 // generate all full hour timezones (no fractional timezones)
242 for (var x = -12, idx = timezones.length; x <= +14; x++, idx++) {
243 var hours = (x >= 0 ? '+' : '-') + padLeft(x >=0 ? x : -x, 2);
244 timezones[idx] = { value: hours + '00', descr: 'UTC' + hours + ':00'};
246 timezones[idx].descr = 'UTC\u00B100:00'; // 'UTC±00:00'
254 * Generate <options> elements for timezone select UI
256 * @param {String} tzSelected: default timezone
257 * @returns {DocumentFragment} list of options elements to appendChild
259 function generateTZOptions(tzSelected) {
260 var elems = document.createDocumentFragment();
261 var timezones = generateTZList();
263 for (var i = 0, len = timezones.length; i < len; i++) {
264 var tzone = timezones[i];
265 var option = document.createElement("option");
266 if (tzone.value === tzSelected) {
267 option.defaultSelected = true;
269 option.value = tzone.value;
270 option.appendChild(document.createTextNode(tzone.descr));
272 elems.appendChild(option);
279 /* ...................................................................... */
280 /* Event handlers and/or their generators */
283 * Create event handler that select timezone and closes timezone select UI.
284 * To be used as $('select[name="tzselect"]').onchange handler.
286 * @param {DocumentFragment} tzSelectFragment: timezone selection UI
287 * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
288 * @param {String} tzCookieInfo.name: name of cookie to save result of selection
289 * @param {String} tzClassName: specifies element where UI was installed
290 * @returns {Function} event handler
292 function selectTZHandler(tzSelectFragment, tzCookieInfo, tzClassName) {
293 //return function selectTZ(event) {
294 return function (event) {
295 event = event || window.event;
296 var target = event.target || event.srcElement;
298 var selected = target.options.item(target.selectedIndex);
299 removeChangeTZForm(tzSelectFragment, target, tzClassName);
302 selected.defaultSelected = true;
303 setCookie(tzCookieInfo.name, selected.value, tzCookieInfo);
304 fixDatetimeTZ(selected.value, tzClassName);
310 * Create event handler that closes timezone select UI.
311 * To be used e.g. as $('.closebutton').onclick handler.
313 * @param {DocumentFragment} tzSelectFragment: timezone selection UI
314 * @param {String} tzClassName: specifies element where UI was installed
315 * @returns {Function} event handler
317 function closeTZFormHandler(tzSelectFragment, tzClassName) {
318 //return function closeTZForm(event) {
319 return function (event) {
320 event = event || window.event;
321 var target = event.target || event.srcElement;
323 removeChangeTZForm(tzSelectFragment, target, tzClassName);
327 /* end of adjust-timezone.js */