128、sea.js源码（非压缩版）

水深无声 2023-06-05 08:22 37阅读 0赞

1、AMD是提前执行，AMD中require的所有模块都会先加载完成，
    2、CMD是延迟执行，CMD中require的模块再需要的时候再去执行

/**
     * Sea.js @VERSION | seajs.org/LICENSE.md
     */
    (function (global, undefined) {
    
        // Avoid conflicting when `sea.js` is loaded multiple times
        if (global.seajs) {
            return
        }
    
    
        var seajs = global.seajs = {
            // The current version of Sea.js being used
            version: "@VERSION" } var data = seajs.data = {} /** * config.js - The configuration for the loader */ // The root path to use for id2uri parsing data.base = loaderDir // The loader directory data.dir = loaderDir // The current working directory data.cwd = cwd // The charset for requesting files data.charset = "utf-8" // data.alias - An object containing shorthands of module id // data.paths - An object containing path shorthands in module id // data.vars - The {xxx} variables in module id // data.map - An array containing rules to map module uri // data.debug - Debug mode. The default value is false  seajs.config = function (configData) { for (var key in configData) { var curr = configData[key] var prev = data[key] // Merge object config such as alias, vars if (prev && isObject(prev)) { for (var k in curr) { prev[k] = curr[k] } } else { // Concat array config such as map if (isArray(prev)) { curr = prev.concat(curr) } // Make sure that `data.base` is an absolute path else if (key === "base") { // Make sure end with "/" if (curr.slice(-1) !== "/") { curr += "/" } curr = addBase(curr) } // Set config data[key] = curr } } emit("config", configData) return seajs } /** * module.js - The core of module loader */ var cachedMods = seajs.cache = {} var anonymousMeta var fetchingList = {} var fetchedList = {} var callbackList = {} var STATUS = Module.STATUS = { // 1 - The `module.uri` is being fetched FETCHING: 1, // 2 - The meta data has been saved to cachedMods SAVED: 2, // 3 - The `module.dependencies` are being loaded LOADING: 3, // 4 - The module are ready to execute LOADED: 4, // 5 - The module is being executed EXECUTING: 5, // 6 - The `module.exports` is available EXECUTED: 6 } function Module(uri, deps) { this.uri = uri this.dependencies = deps || [] this.exports = null this.status = 0 // Who depends on me this._waitings = {} // The number of unloaded dependencies this._remain = 0 } // Resolve module.dependencies Module.prototype.resolve = function () { var mod = this var ids = mod.dependencies var uris = [] for (var i = 0, len = ids.length; i < len; i++) { uris[i] = Module.resolve(ids[i], mod.uri) } return uris } // Load module.dependencies and fire onload when all done Module.prototype.load = function () { var mod = this // If the module is being loaded, just wait it onload call if (mod.status >= STATUS.LOADING) { return } mod.status = STATUS.LOADING // Emit `load` event for plugins such as combo plugin var uris = mod.resolve() emit("load", uris) var len = mod._remain = uris.length var m // Initialize modules and register waitings for (var i = 0; i < len; i++) { m = Module.get(uris[i]) if (m.status < STATUS.LOADED) { // Maybe duplicate: When module has dupliate dependency, it should be it's count, not 1 m._waitings[mod.uri] = (m._waitings[mod.uri] || 0) + 1 } else { mod._remain-- } } if (mod._remain === 0) { mod.onload() return } // Begin parallel loading var requestCache = {} for (i = 0; i < len; i++) { m = cachedMods[uris[i]] if (m.status < STATUS.FETCHING) { m.fetch(requestCache) } else if (m.status === STATUS.SAVED) { m.load() } } // Send all requests at last to avoid cache bug in IE6-9. Issues#808 for (var requestUri in requestCache) { if (requestCache.hasOwnProperty(requestUri)) { requestCache[requestUri]() } } } // Call this method when module is loaded Module.prototype.onload = function () { var mod = this mod.status = STATUS.LOADED if (mod.callback) { mod.callback() } // Notify waiting modules to fire onload var waitings = mod._waitings var uri, m for (uri in waitings) { if (waitings.hasOwnProperty(uri)) { m = cachedMods[uri] m._remain -= waitings[uri] if (m._remain === 0) { m.onload() } } } // Reduce memory taken delete mod._waitings delete mod._remain } // Fetch a module Module.prototype.fetch = function (requestCache) { var mod = this var uri = mod.uri mod.status = STATUS.FETCHING // Emit `fetch` event for plugins such as combo plugin var emitData = { uri: uri } emit("fetch", emitData) var requestUri = emitData.requestUri || uri // Empty uri or a non-CMD module if (!requestUri || fetchedList[requestUri]) { mod.load() return } if (fetchingList[requestUri]) { callbackList[requestUri].push(mod) return } fetchingList[requestUri] = true callbackList[requestUri] = [mod] // Emit `request` event for plugins such as text plugin emit("request", emitData = { uri: uri, requestUri: requestUri, onRequest: onRequest, charset: data.charset }) if (!emitData.requested) { requestCache ? requestCache[emitData.requestUri] = sendRequest : sendRequest() } function sendRequest() { seajs.request(emitData.requestUri, emitData.onRequest, emitData.charset) } function onRequest() { delete fetchingList[requestUri] fetchedList[requestUri] = true // Save meta data of anonymous module if (anonymousMeta) { Module.save(uri, anonymousMeta) anonymousMeta = null } // Call callbacks var m, mods = callbackList[requestUri] delete callbackList[requestUri] while ((m = mods.shift())) m.load() } } // Execute a module Module.prototype.exec = function () { var mod = this // When module is executed, DO NOT execute it again. When module // is being executed, just return `module.exports` too, for avoiding // circularly calling if (mod.status >= STATUS.EXECUTING) { return mod.exports } mod.status = STATUS.EXECUTING // Create require var uri = mod.uri function require(id) { return Module.get(require.resolve(id)).exec() } require.resolve = function (id) { return Module.resolve(id, uri) } require.async = function (ids, callback) { Module.use(ids, callback, uri + "_async_" + cid()) return require } // Exec factory var factory = mod.factory var exports = isFunction(factory) ? factory(require, mod.exports = {}, mod) : factory if (exports === undefined) { exports = mod.exports } // Reduce memory leak delete mod.factory mod.exports = exports mod.status = STATUS.EXECUTED // Emit `exec` event emit("exec", mod) return exports } // Resolve id to uri Module.resolve = function (id, refUri) { // Emit `resolve` event for plugins such as text plugin var emitData = { id: id, refUri: refUri } emit("resolve", emitData) return emitData.uri || seajs.resolve(emitData.id, refUri) } // Define a module Module.define = function (id, deps, factory) { var argsLen = arguments.length // define(factory) if (argsLen === 1) { factory = id id = undefined } else if (argsLen === 2) { factory = deps // define(deps, factory) if (isArray(id)) { deps = id id = undefined } // define(id, factory) else { deps = undefined } } // Parse dependencies according to the module factory code if (!isArray(deps) && isFunction(factory)) { deps = parseDependencies(factory.toString()) } var meta = { id: id, uri: Module.resolve(id), deps: deps, factory: factory } // Try to derive uri in IE6-9 for anonymous modules if (!meta.uri && doc.attachEvent) { var script = getCurrentScript() if (script) { meta.uri = script.src } // NOTE: If the id-deriving methods above is failed, then falls back // to use onload event to get the uri  } // Emit `define` event, used in nocache plugin, seajs node version etc emit("define", meta) meta.uri ? Module.save(meta.uri, meta) : // Save information for "saving" work in the script onload event anonymousMeta = meta } // Save meta data to cachedMods Module.save = function (uri, meta) { var mod = Module.get(uri) // Do NOT override already saved modules if (mod.status < STATUS.SAVED) { mod.id = meta.id || uri mod.dependencies = meta.deps || [] mod.factory = meta.factory mod.status = STATUS.SAVED emit("save", mod) } } // Get an existed module or create a new one Module.get = function (uri, deps) { return cachedMods[uri] || (cachedMods[uri] = new Module(uri, deps)) } // Use function is equal to load a anonymous module Module.use = function (ids, callback, uri) { var mod = Module.get(uri, isArray(ids) ? ids : [ids]) mod.callback = function () { var exports = [] var uris = mod.resolve() for (var i = 0, len = uris.length; i < len; i++) { exports[i] = cachedMods[uris[i]].exec() } if (callback) { callback.apply(global, exports) } delete mod.callback } mod.load() } // Public API  seajs.use = function (ids, callback) { Module.use(ids, callback, data.cwd + "_use_" + cid()) return seajs } Module.define.cmd = {} global.define = Module.define // For Developers  seajs.Module = Module data.fetchedList = fetchedList data.cid = cid seajs.require = function (id) { var mod = Module.get(Module.resolve(id)) if (mod.status < STATUS.EXECUTING) { mod.onload() mod.exec() } return mod.exports } var seajs = global.seajs = { // The current version of Sea.js being used version: "@VERSION" } var data = seajs.data = {} /** * util-deps.js - The parser for dependencies * ref: tests/research/parse-dependencies/test.html */ var REQUIRE_RE = /"(?:\\"|[^"])*"|'(?:\\'|[^'])*'|\/\*[\S\s]*?\*\/|\/(?:\\\/|[^\/\r\n])+\/(?=[^\/])|\/\/.*|\.\s*require|(?:^|[^$])\brequire\s*$\s*(["'])(.+?)\1\s*$/g var SLASH_RE = /\\\\/g function parseDependencies(code) { var ret = [] code.replace(SLASH_RE, "") .replace(REQUIRE_RE, function (m, m1, m2) { if (m2) { ret.push(m2) } }) return ret } /** * util-events.js - The minimal events support */ var events = data.events = {} // Bind event seajs.on = function (name, callback) { var list = events[name] || (events[name] = []) list.push(callback) return seajs } // Remove event. If `callback` is undefined, remove all callbacks for the // event. If `event` and `callback` are both undefined, remove all callbacks // for all events seajs.off = function (name, callback) { // Remove *all* events if (!(name || callback)) { events = data.events = {} return seajs } var list = events[name] if (list) { if (callback) { for (var i = list.length - 1; i >= 0; i--) { if (list[i] === callback) { list.splice(i, 1) } } } else { delete events[name] } } return seajs } // Emit event, firing all bound callbacks. Callbacks receive the same // arguments as `emit` does, apart from the event name var emit = seajs.emit = function (name, data) { var list = events[name], fn if (list) { // Copy callback lists to prevent modification list = list.slice() // Execute event callbacks, use index because it's the faster. for (var i = 0, len = list.length; i < len; i++) { list[i](data) } } return seajs } /** * util-lang.js - The minimal language enhancement */ function isType(type) { return function (obj) { return {}.toString.call(obj) == "[object " + type + "]" } } var isObject = isType("Object") var isString = isType("String") var isArray = Array.isArray || isType("Array") var isFunction = isType("Function") var _cid = 0 function cid() { return _cid++ } /** * util-path.js - The utilities for operating path such as id, uri */ var DIRNAME_RE = /[^?#]*\// var DOT_RE = /\/\.\//g var DOUBLE_DOT_RE = /\/[^/]+\/\.\.\// var MULTI_SLASH_RE = /([^:/])\/+\//g // Extract the directory portion of a path // dirname("a/b/c.js?t=123#xx/zz") ==> "a/b/" // ref: http://jsperf.com/regex-vs-split/2 function dirname(path) { return path.match(DIRNAME_RE)[0] } // Canonicalize a path // realpath("http://test.com/a//./b/../c") ==> "http://test.com/a/c" function realpath(path) { // /a/b/./c/./d ==> /a/b/c/d path = path.replace(DOT_RE, "/") /* @author wh1100717 a//b/c ==> a/b/c a///b/c ==> a/b/c DOUBLE_DOT_RE matches a/b/c//../d path correctly only if replace // with / first */ path = path.replace(MULTI_SLASH_RE, "$1/") // a/b/c/../../d ==> a/b/../d ==> a/d while

转载于:https://www.cnblogs.com/gushixianqiancheng/p/11257402.html