webpack/lib/webworker/ImportScriptsChunkLoadingRuntimeModule.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, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
*/

"use strict";

const RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const Template = require("../Template");
const {
	getChunkFilenameTemplate
} = require("../javascript/JavascriptModulesPlugin");
const { getUndoPath } = require("../util/identifier");

class ImportScriptsChunkLoadingRuntimeModule extends RuntimeModule {
	constructor(runtimeRequirements) {
		super("importScripts chunk loading", 10);
		this.runtimeRequirements = runtimeRequirements;
	}

	/**
	 * @returns {string} runtime code
	 */
	generate() {
		const {
			chunk,
			compilation: {
				runtimeTemplate,
				outputOptions: { globalObject, chunkLoadingGlobal, hotUpdateGlobal }
			}
		} = this;
		const fn = RuntimeGlobals.ensureChunkHandlers;
		const withBaseURI = this.runtimeRequirements.has(RuntimeGlobals.baseURI);
		const withLoading = this.runtimeRequirements.has(
			RuntimeGlobals.ensureChunkHandlers
		);
		const withHmr = this.runtimeRequirements.has(
			RuntimeGlobals.hmrDownloadUpdateHandlers
		);
		const withHmrManifest = this.runtimeRequirements.has(
			RuntimeGlobals.hmrDownloadManifest
		);
		const chunkLoadingGlobalExpr = `${globalObject}[${JSON.stringify(
			chunkLoadingGlobal
		)}]`;
		const outputName = this.compilation.getPath(
			getChunkFilenameTemplate(chunk, this.compilation.outputOptions),
			{
				chunk,
				contentHashType: "javascript"
			}
		);
		const rootOutputDir = getUndoPath(outputName, false);
		return Template.asString([
			withBaseURI
				? Template.asString([
						`${RuntimeGlobals.baseURI} = self.location + ${JSON.stringify(
							rootOutputDir ? "/../" + rootOutputDir : ""
						)};`
				  ])
				: "// no baseURI",
			"",
			"// object to store loaded chunks",
			'// "1" means "already loaded"',
			"var installedChunks = {",
			Template.indent(
				chunk.ids.map(id => `${JSON.stringify(id)}: 1`).join(",\n")
			),
			"};",
			"",
			withLoading
				? Template.asString([
						"// importScripts chunk loading",
						`var chunkLoadingCallback = ${runtimeTemplate.basicFunction(
							"data",
							[
								runtimeTemplate.destructureArray(
									["chunkIds", "moreModules", "runtime"],
									"data"
								),
								"for(var moduleId in moreModules) {",
								Template.indent([
									`if(${RuntimeGlobals.hasOwnProperty}(moreModules, moduleId)) {`,
									Template.indent(
										`${RuntimeGlobals.moduleFactories}[moduleId] = moreModules[moduleId];`
									),
									"}"
								]),
								"}",
								"if(runtime) runtime(__webpack_require__);",
								"while(chunkIds.length)",
								Template.indent("installedChunks[chunkIds.pop()] = 1;"),
								"parentChunkLoadingFunction(data);"
							]
						)};`,
						`${fn}.i = ${runtimeTemplate.basicFunction("chunkId, promises", [
							'// "1" is the signal for "already loaded"',
							"if(!installedChunks[chunkId]) {",
							Template.indent([
								`importScripts(${JSON.stringify(rootOutputDir)} + ${
									RuntimeGlobals.getChunkScriptFilename
								}(chunkId));`
							]),
							"}"
						])};`,
						"",
						`var chunkLoadingGlobal = ${chunkLoadingGlobalExpr} = ${chunkLoadingGlobalExpr} || [];`,
						"var parentChunkLoadingFunction = chunkLoadingGlobal.push.bind(chunkLoadingGlobal);",
						"chunkLoadingGlobal.push = chunkLoadingCallback;"
				  ])
				: "// no chunk loading",
			"",
			withHmr
				? Template.asString([
						"function loadUpdateChunk(chunkId, updatedModulesList) {",
						Template.indent([
							"var success = false;",
							`${globalObject}[${JSON.stringify(
								hotUpdateGlobal
							)}] = ${runtimeTemplate.basicFunction("_, moreModules, runtime", [
								"for(var moduleId in moreModules) {",
								Template.indent([
									`if(${RuntimeGlobals.hasOwnProperty}(moreModules, moduleId)) {`,
									Template.indent([
										"currentUpdate[moduleId] = moreModules[moduleId];",
										"if(updatedModulesList) updatedModulesList.push(moduleId);"
									]),
									"}"
								]),
								"}",
								"if(runtime) currentUpdateRuntime.push(runtime);",
								"success = true;"
							])};`,
							"// start update chunk loading",
							`importScripts(${JSON.stringify(rootOutputDir)} + ${
								RuntimeGlobals.getChunkUpdateScriptFilename
							}(chunkId));`,
							'if(!success) throw new Error("Loading update chunk failed for unknown reason");'
						]),
						"}",
						"",
						Template.getFunctionContent(
							require("../hmr/JavascriptHotModuleReplacement.runtime.js")
						)
							.replace(/\$key\$/g, "importScrips")
							.replace(/\$installedChunks\$/g, "installedChunks")
							.replace(/\$loadUpdateChunk\$/g, "loadUpdateChunk")
							.replace(/\$moduleCache\$/g, RuntimeGlobals.moduleCache)
							.replace(/\$moduleFactories\$/g, RuntimeGlobals.moduleFactories)
							.replace(
								/\$ensureChunkHandlers\$/g,
								RuntimeGlobals.ensureChunkHandlers
							)
							.replace(/\$hasOwnProperty\$/g, RuntimeGlobals.hasOwnProperty)
							.replace(/\$hmrModuleData\$/g, RuntimeGlobals.hmrModuleData)
							.replace(
								/\$hmrDownloadUpdateHandlers\$/g,
								RuntimeGlobals.hmrDownloadUpdateHandlers
							)
							.replace(
								/\$hmrInvalidateModuleHandlers\$/g,
								RuntimeGlobals.hmrInvalidateModuleHandlers
							)
				  ])
				: "// no HMR",
			"",
			withHmrManifest
				? Template.asString([
						`${
							RuntimeGlobals.hmrDownloadManifest
						} = ${runtimeTemplate.basicFunction("", [
							'if (typeof fetch === "undefined") throw new Error("No browser support: need fetch API");',
							`return fetch(${RuntimeGlobals.publicPath} + ${
								RuntimeGlobals.getUpdateManifestFilename
							}()).then(${runtimeTemplate.basicFunction("response", [
								"if(response.status === 404) return; // no update available",
								'if(!response.ok) throw new Error("Failed to fetch update manifest " + response.statusText);',
								"return response.json();"
							])});`
						])};`
				  ])
				: "// no HMR manifest"
		]);
	}
}

module.exports = ImportScriptsChunkLoadingRuntimeModule;