webpack/lib/ExternalModule.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";
const Module = require("./Module");
const OriginalSource = require("webpack-sources").OriginalSource;
const RawSource = require("webpack-sources").RawSource;
const WebpackMissingModule = require("./dependencies/WebpackMissingModule");

class ExternalModule extends Module {
	constructor(request, type) {
		super();
		this.chunkCondition = function(chunk) {
			return chunk.hasEntryModule();
		};
		this.request = request;
		this.type = type;
		this.built = false;
		this.external = true;
	}

	identifier() {
		return "external " + JSON.stringify(this.request);
	}

	readableIdentifier() {
		return "external " + JSON.stringify(this.request);
	}

	needRebuild() {
		return false;
	}

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

	source() {
		let str = "throw new Error('Externals not supported');";
		let 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);
		}
	}

	size() {
		return 42;
	}
}

module.exports = ExternalModule;