webpack/lib/ContextModule.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var Module = require("./Module");
var OriginalSource = require("webpack-core/lib/OriginalSource");
var RawSource = require("webpack-core/lib/RawSource");

function ContextModule(resolveDependencies, context, recursive, regExp, addon) {
	Module.call(this);
	this.resolveDependencies = resolveDependencies;
	this.context = context;
	this.recursive = recursive;
	this.regExp = regExp;
	this.addon = addon;
	this.cacheable = true;
	this.contextDependencies = [context];
	this.built = false;
}
module.exports = ContextModule;

ContextModule.prototype = Object.create(Module.prototype);

ContextModule.prototype.identifier = function() {
	var identifier = "";
	identifier += this.context + " ";
	if(!this.recursive)
		identifier += "nonrecursive ";
	if(this.addon)
		identifier += this.addon;
	if(this.regExp)
		identifier += this.regExp;
	return identifier.replace(/ $/, "");
};

function prettyRegExp(str) {
	return str.substring(1, str.length - 1);
}

ContextModule.prototype.readableIdentifier = function(requestShortener) {
	var identifier = "";
	identifier += requestShortener.shorten(this.context) + " ";
	if(!this.recursive)
		identifier += "nonrecursive ";
	if(this.addon)
		identifier += requestShortener.shorten(this.addon);
	if(this.regExp)
		identifier += prettyRegExp(this.regExp + "");
	return identifier.replace(/ $/, "");
};

ContextModule.prototype.needRebuild = function(fileTimestamps, contextTimestamps) {
	var ts = contextTimestamps[this.context];
	if(!ts) return true;
	return ts >= this.builtTime;
};

ContextModule.prototype.disconnect = function disconnect() {
	this.built = false;
	Module.prototype.disconnect.call(this);
};

ContextModule.prototype.build = function(options, compilation, resolver, fs, callback) {
	this.built = true;
	this.builtTime = new Date().getTime();
	var addon = this.addon;
	this.resolveDependencies(fs, this.context, this.recursive, this.regExp, function(err, dependencies) {
		if(err) return callback(err);
		dependencies.forEach(function(dep) {
			dep.userRequest = dep.request;
			dep.request = addon + dep.userRequest;
		});
		this.dependencies = dependencies;
		callback();
	}.bind(this));
};

ContextModule.prototype.source = function(dependencyTemplates, outputOptions, requestShortener) {
	if(this.dependencies.length > 0) {
		var map = {};
		this.dependencies.slice().sort(function(a,b) {
			if(a.userRequest === b.userRequest) return 0;
			return a.userRequest < b.userRequest ? -1 : 1;
		}).forEach(function(dep) {
			if(dep.module)
				map[dep.userRequest] = dep.module.id
		});
		var str = [
			"var map = ", JSON.stringify(map, null, "\t"), ";\n",
			"function webpackContext(req) {\n",
			"\treturn __webpack_require__(webpackContextResolve(req));\n",
			"};\n",
			"function webpackContextResolve(req) {\n",
			"\treturn map[req] || (function() { throw new Error(\"Cannot find module '\" + req + \"'.\") }());\n",
			"};\n",
			"webpackContext.id = "+this.id+";\n",
			"webpackContext.keys = function webpackContextKeys() {\n",
			"\treturn Object.keys(map);\n",
			"};\n",
			"webpackContext.resolve = webpackContextResolve;\n",
			"module.exports = webpackContext;\n",
		];
	} else {
		var str = [
			"function webpackContext(req) {\n",
			"\tthrow new Error(\"Cannot find module '\" + req + \"'.\");\n",
			"}\n",
			"webpackContext.resolve = webpackContext;\n",
			"webpackContext.keys = function() { return []; };\n",
			"module.exports = webpackContext;\n"
		];
	}
	if(this.useSourceMap) {
		return new OriginalSource(str.join(""), this.identifier());
	} else {
		return new RawSource(str.join(""));
	}
};

ContextModule.prototype.size = function() {
	return this.dependencies.map(function(dep) {
		return dep.userRequest.length + 5;
	}).reduce(function(a, b) { return a+b; }, 160);
};