Files
less.js/lib/less-browser/index.js
Christian Hammond f66757554f Fix synchronously loading/applying stylesheets on page load.
Starting in 2.0, stylesheet loading became asynchronous, through the
usage of promises for both calculating the list of stylesheets and the
initial call to less.refresh(). This resulted in visual issues while
loading on some browsers (noticed in Firefox and Safari), along with
breakages of any custom JavaScript that depended on the computed style
of elements on the page, due to race conditions.

This change preserves the promise for initial page loading, in order to
retain support for less.pageLoadFinished, but immediately executes the
stylesheet scan (through a new less.registerStylesheetsImmediately
function) and the less.refresh() call. That resulting behavior matches
versions of less prior to 2.0.

This unveiled a regression in registering functions, both in the browser
and in unit tests, that was not previously noticed due to the
asynchronous load. Registered functions would have a 'less' variable set
to the less options, and not less itself, when not going through the
asynchronous loading mode. This meant that both unit tests and
real-world function registration would break when the sync page loading
was fixed. Overriding window.less to point to the actual less module and
not less.options during bootstrap fixes this.

This fixes #2317.
2015-04-28 02:08:39 -07:00

265 lines
9.1 KiB
JavaScript

//
// index.js
// Should expose the additional browser functions on to the less object
//
var addDataAttr = require("./utils").addDataAttr,
browser = require("./browser");
module.exports = function(window, options) {
var document = window.document;
var less = require('../less')();
//module.exports = less;
less.options = options;
var environment = less.environment,
FileManager = require("./file-manager")(options, less.logger),
fileManager = new FileManager();
environment.addFileManager(fileManager);
less.FileManager = FileManager;
require("./log-listener")(less, options);
var errors = require("./error-reporting")(window, less, options);
var cache = less.cache = options.cache || require("./cache")(window, options, less.logger);
//Setup user functions
if (options.functions) {
less.functions.functionRegistry.addMultiple(options.functions);
}
var typePattern = /^text\/(x-)?less$/;
function postProcessCSS(styles) { // deprecated, use a plugin for postprocesstasks
if (options.postProcessor && typeof options.postProcessor === 'function') {
styles = options.postProcessor.call(styles, styles) || styles;
}
return styles;
}
function clone(obj) {
var cloned = {};
for (var prop in obj) {
if (obj.hasOwnProperty(prop)) {
cloned[prop] = obj[prop];
}
}
return cloned;
}
// only really needed for phantom
function bind(func, thisArg) {
var curryArgs = Array.prototype.slice.call(arguments, 2);
return function() {
var args = curryArgs.concat(Array.prototype.slice.call(arguments, 0));
return func.apply(thisArg, args);
};
}
function loadStyles(modifyVars) {
var styles = document.getElementsByTagName('style'),
style;
for (var i = 0; i < styles.length; i++) {
style = styles[i];
if (style.type.match(typePattern)) {
var instanceOptions = clone(options);
instanceOptions.modifyVars = modifyVars;
var lessText = style.innerHTML || '';
instanceOptions.filename = document.location.href.replace(/#.*$/, '');
/*jshint loopfunc:true */
// use closure to store current style
less.render(lessText, instanceOptions,
bind(function(style, e, result) {
if (e) {
errors.add(e, "inline");
} else {
style.type = 'text/css';
if (style.styleSheet) {
style.styleSheet.cssText = result.css;
} else {
style.innerHTML = result.css;
}
}
}, null, style));
}
}
}
function loadStyleSheet(sheet, callback, reload, remaining, modifyVars) {
var instanceOptions = clone(options);
addDataAttr(instanceOptions, sheet);
instanceOptions.mime = sheet.type;
if (modifyVars) {
instanceOptions.modifyVars = modifyVars;
}
function loadInitialFileCallback(loadedFile) {
var data = loadedFile.contents,
path = loadedFile.filename,
webInfo = loadedFile.webInfo;
var newFileInfo = {
currentDirectory: fileManager.getPath(path),
filename: path,
rootFilename: path,
relativeUrls: instanceOptions.relativeUrls};
newFileInfo.entryPath = newFileInfo.currentDirectory;
newFileInfo.rootpath = instanceOptions.rootpath || newFileInfo.currentDirectory;
if (webInfo) {
webInfo.remaining = remaining;
if (!instanceOptions.modifyVars) {
var css = cache.getCSS(path, webInfo);
if (!reload && css) {
webInfo.local = true;
callback(null, css, data, sheet, webInfo, path);
return;
}
}
}
//TODO add tests around how this behaves when reloading
errors.remove(path);
instanceOptions.rootFileInfo = newFileInfo;
less.render(data, instanceOptions, function(e, result) {
if (e) {
e.href = path;
callback(e);
} else {
result.css = postProcessCSS(result.css);
if (!instanceOptions.modifyVars) {
cache.setCSS(sheet.href, webInfo.lastModified, result.css);
}
callback(null, result.css, data, sheet, webInfo, path);
}
});
}
fileManager.loadFile(sheet.href, null, instanceOptions, environment, function(e, loadedFile) {
if (e) {
callback(e);
return;
}
loadInitialFileCallback(loadedFile);
});
}
function loadStyleSheets(callback, reload, modifyVars) {
for (var i = 0; i < less.sheets.length; i++) {
loadStyleSheet(less.sheets[i], callback, reload, less.sheets.length - (i + 1), modifyVars);
}
}
function initRunningMode() {
if (less.env === 'development') {
less.watchTimer = setInterval(function () {
if (less.watchMode) {
fileManager.clearFileCache();
loadStyleSheets(function (e, css, _, sheet, webInfo) {
if (e) {
errors.add(e, e.href || sheet.href);
} else if (css) {
browser.createCSS(window.document, css, sheet);
}
});
}
}, options.poll);
}
}
//
// Watch mode
//
less.watch = function () {
if (!less.watchMode ) {
less.env = 'development';
initRunningMode();
}
this.watchMode = true;
return true;
};
less.unwatch = function () {clearInterval(less.watchTimer); this.watchMode = false; return false; };
//
// Synchronously get all <link> tags with the 'rel' attribute set to
// "stylesheet/less".
//
less.registerStylesheetsImmediately = function() {
var links = document.getElementsByTagName('link');
less.sheets = [];
for (var i = 0; i < links.length; i++) {
if (links[i].rel === 'stylesheet/less' || (links[i].rel.match(/stylesheet/) &&
(links[i].type.match(typePattern)))) {
less.sheets.push(links[i]);
}
}
};
//
// Asynchronously get all <link> tags with the 'rel' attribute set to
// "stylesheet/less", returning a Promise.
//
less.registerStylesheets = function() {
return new Promise(function(resolve, reject) {
less.registerStylesheetsImmediately();
resolve();
});
};
//
// With this function, it's possible to alter variables and re-render
// CSS without reloading less-files
//
less.modifyVars = function(record) {
return less.refresh(true, record, false);
};
less.refresh = function (reload, modifyVars, clearFileCache) {
if ((reload || clearFileCache) && clearFileCache !== false) {
fileManager.clearFileCache();
}
return new Promise(function (resolve, reject) {
var startTime, endTime, totalMilliseconds;
startTime = endTime = new Date();
loadStyleSheets(function (e, css, _, sheet, webInfo) {
if (e) {
errors.add(e, e.href || sheet.href);
reject(e);
return;
}
if (webInfo.local) {
less.logger.info("loading " + sheet.href + " from cache.");
} else {
less.logger.info("rendered " + sheet.href + " successfully.");
}
browser.createCSS(window.document, css, sheet);
less.logger.info("css for " + sheet.href + " generated in " + (new Date() - endTime) + 'ms');
if (webInfo.remaining === 0) {
totalMilliseconds = new Date() - startTime;
less.logger.info("less has finished. css generated in " + totalMilliseconds + 'ms');
resolve({
startTime: startTime,
endTime: endTime,
totalMilliseconds: totalMilliseconds,
sheets: less.sheets.length
});
}
endTime = new Date();
}, reload, modifyVars);
loadStyles(modifyVars);
});
};
less.refreshStyles = loadStyles;
return less;
};