/*
Live.js - One script closer to Designing in the Browser
Written for Handcraft.com by Martin Kool (@mrtnkl).
Version 4.
Recent change: Made stylesheet and mimetype checks case insensitive.
http://livejs.com
http://livejs.com/license (MIT)
@livejs
Include live.js#css to monitor css changes only.
Include live.js#js to monitor js changes only.
Include live.js#html to monitor html changes only.
Mix and match to monitor a preferred combination such as live.js#html,css
By default, just include live.js to monitor all css, js and html changes.
Live.js can also be loaded as a bookmarklet. It is best to only use it for CSS then,
as a page reload due to a change in html or css would not re-include the bookmarklet.
To monitor CSS and be notified that it has loaded, include it as: live.js#css,notify
*/
(function () {
var headers = { "Etag": 1, "Last-Modified": 1, "Content-Length": 1, "Content-Type": 1 },
resources = {},
pendingRequests = {},
currentLinkElements = {},
oldLinkElements = {},
interval = 1000,
loaded = false,
active = { "html": 1, "css": 1, "js": 1 };
var Live = {
// performs a cycle per interval
heartbeat: function () {
if (document.body) {
// make sure all resources are loaded on first activation
if (!loaded) Live.loadresources();
Live.checkForChanges();
}
setTimeout(Live.heartbeat, interval);
},
// loads all local css and js resources upon first activation
loadresources: function () {
// helper method to assert if a given url is local
function isLocal(url) {
var loc = document.location,
reg = new RegExp("^\\.|^\/(?!\/)|^[\\w]((?!://).)*$|" + loc.protocol + "//" + loc.host);
return url.match(reg);
}
// gather all resources
var scripts = document.getElementsByTagName("script"),
links = document.getElementsByTagName("link"),
uris = [];
// track local js urls
for (var i = 0; i < scripts.length; i++) {
var script = scripts[i], src = script.getAttribute("src");
if (src && isLocal(src))
uris.push(src);
if (src && src.match(/\blive.js#/)) {
for (var type in active)
active[type] = src.match("[#,|]" + type) != null
if (src.match("notify"))
alert("Live.js is loaded.");
}
}
if (!active.js) uris = [];
if (active.html) uris.push(document.location.href);
// track local css urls
for (var i = 0; i < links.length && active.css; i++) {
var link = links[i], rel = link.getAttribute("rel"), href = link.getAttribute("href", 2);
if (href && rel && rel.match(new RegExp("stylesheet", "i")) && isLocal(href)) {
uris.push(href);
currentLinkElements[href] = link;
}
}
// initialize the resources info
for (var i = 0; i < uris.length; i++) {
var url = uris[i];
Live.getHead(url, function (url, info) {
resources[url] = info;
});
}
// add rule for morphing between old and new css files
var head = document.getElementsByTagName("head")[0],
style = document.createElement("style"),
rule = "transition: all .3s ease-out;"
css = [".livejs-loading * { ", rule, " -webkit-", rule, "-moz-", rule, "-o-", rule, "}"].join('');
style.setAttribute("type", "text/css");
head.appendChild(style);
style.styleSheet ? style.styleSheet.cssText = css : style.appendChild(document.createTextNode(css));
// yep
loaded = true;
},
// check all tracking resources for changes
checkForChanges: function () {
for (var url in resources) {
if (pendingRequests[url])
continue;
Live.getHead(url, function (url, newInfo) {
var oldInfo = resources[url],
hasChanged = false;
resources[url] = newInfo;
for (var header in oldInfo) {
// do verification based on the header type
var oldValue = oldInfo[header],
newValue = newInfo[header],
contentType = newInfo["Content-Type"];
switch (header.toLowerCase()) {
case "etag":
if (!newValue) break;
// fall through to default
default:
hasChanged = oldValue != newValue;
break;
}
// if changed, act
if (hasChanged) {
Live.refreshResource(url, contentType);
break;
}
}
});
}
},
// act upon a changed url of certain content type
refreshResource: function (url, type) {
switch (type.toLowerCase()) {
// css files can be reloaded dynamically by replacing the link element
case "text/css":
var link = currentLinkElements[url],
html = document.body.parentNode,
head = link.parentNode,
next = link.nextSibling,
newLink = document.createElement("link");
html.className = html.className.replace(/\s*livejs\-loading/gi, '') + ' livejs-loading';
newLink.setAttribute("type", "text/css");
newLink.setAttribute("rel", "stylesheet");
newLink.setAttribute("href", url + "?now=" + new Date() * 1);
next ? head.insertBefore(newLink, next) : head.appendChild(newLink);
currentLinkElements[url] = newLink;
oldLinkElements[url] = link;
// schedule removal of the old link
Live.removeoldLinkElements();
break;
// check if an html resource is our current url, then reload
case "text/html":
if (url != document.location.href)
return;
// local javascript changes cause a reload as well
case "text/javascript":
case "application/javascript":
case "application/x-javascript":
document.location.reload();
}
},
// removes the old stylesheet rules only once the new one has finished loading
removeoldLinkElements: function () {
var pending = 0;
for (var url in oldLinkElements) {
// if this sheet has any cssRules, delete the old link
try {
var link = currentLinkElements[url],
oldLink = oldLinkElements[url],
html = document.body.parentNode,
sheet = link.sheet || link.styleSheet,
rules = sheet.rules || sheet.cssRules;
if (rules.length >= 0) {
oldLink.parentNode.removeChild(oldLink);
delete oldLinkElements[url];
setTimeout(function () {
html.className = html.className.replace(/\s*livejs\-loading/gi, '');
}, 100);
}
} catch (e) {
pending++;
}
if (pending) setTimeout(Live.removeoldLinkElements, 50);
}
},
// performs a HEAD request and passes the header info to the given callback
getHead: function (url, callback) {
pendingRequests[url] = true;
var xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XmlHttp");
xhr.open("HEAD", url, true);
xhr.onreadystatechange = function () {
delete pendingRequests[url];
if (xhr.readyState == 4 && xhr.status != 304) {
xhr.getAllResponseHeaders();
var info = {};
for (var h in headers) {
var value = xhr.getResponseHeader(h);
// adjust the simple Etag variant to match on its significant part
if (h.toLowerCase() == "etag" && value) value = value.replace(/^W\//, '');
if (h.toLowerCase() == "content-type" && value) value = value.replace(/^(.*?);.*?$/i, "$1");
info[h] = value;
}
callback(url, info);
}
}
xhr.send();
}
};
// start listening
if (document.location.protocol != "file:") {
if (!window.liveJsLoaded)
Live.heartbeat();
window.liveJsLoaded = true;
}
else if (window.console)
console.log("Live.js doesn't support the file protocol. It needs http.");
})();