webpack/lib/ExternalModule.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");
var WebpackMissingModule = require("./dependencies/WebpackMissingModule");

function ExternalModule(request, type) {
	Module.call(this);
	this.request = request;
	this.type = type;
	this.built = false;
}
module.exports = ExternalModule;

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

ExternalModule.prototype.external = true;

ExternalModule.prototype.identifier = function() {
	return "external " + JSON.stringify(this.request);
};

ExternalModule.prototype.readableIdentifier = function(requestShortener) {
	return "external " + JSON.stringify(this.request);
};

ExternalModule.prototype.needRebuild = function(fileTimestamps, contextTimestamps) {
	return false;
};

ExternalModule.prototype.build = function(options, compilation, resolver, fs, callback) {
	this.builtTime = new Date().getTime();
	callback();
};

ExternalModule.prototype.source = function(dependencyTemplates, outputOptions, requestShortener) {
	var str = "throw new Error('Externals not supported');";
	var request = this.request;
	if(typeof request === "object") request = request[this.type];
	switch(this.type) {
	case "this":
	case "window":
	case "global":
		if(Array.isArray(request)) {
			str = "(function() { module.exports = " + this.type + request.map(function(r) {
				return "[" + JSON.stringify(r) + "]";
			}).join("") + "; }());";
		} else
			str = "(function() { module.exports = " + this.type + "[" + JSON.stringify(request) + "]; }());";
		break;
	case "commonjs":
	case "commonjs2":
		if(Array.isArray(request)) {
			str = "module.exports = require(" + JSON.stringify(request[0]) + ")" + request.slice(1).map(function(r) {
				return "[" + JSON.stringify(r) + "]";
			}).join("") + ";";
		} else
			str = "module.exports = require(" + JSON.stringify(request) + ");";
		break;
	case "amd":
	case "umd":
	case "umd2":
		str = "";
		if(this.optional) {
			str += "if(typeof __WEBPACK_EXTERNAL_MODULE_" + this.id + "__ === 'undefined') {" + WebpackMissingModule.moduleCode(request) + "}\n";
		}
		str += "module.exports = __WEBPACK_EXTERNAL_MODULE_" + this.id + "__;";
		break;
	default:
		str = "";
		if(this.optional) {
			str += "if(typeof " + request + " === 'undefined') {" + WebpackMissingModule.moduleCode(request) + "}\n";
		}
		str += "module.exports = " + request + ";";
		break;
	}
	if(this.useSourceMap) {
		return new OriginalSource(str, this.identifier());
	} else {
		return new RawSource(str);
	}
};

ExternalModule.prototype.size = function() {
	return 42;
};