webpack/lib/PrefetchPlugin.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports 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
	Author Tobias Koppers @sokra
*/

"use strict";

const PrefetchDependency = require("./dependencies/PrefetchDependency");

/** @typedef {import("./Compiler")} Compiler */

const PLUGIN_NAME = "PrefetchPlugin";

class PrefetchPlugin {
	/**
	 * Creates an instance of PrefetchPlugin.
	 * @param {string} context context or request if context is not set
	 * @param {string=} request request
	 */
	constructor(context, request) {
		if (request) {
			this.context = context;
			this.request = request;
		} else {
			this.context = null;
			this.request = context;
		}
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				compilation.dependencyFactories.set(
					PrefetchDependency,
					normalModuleFactory
				);
			}
		);
		compiler.hooks.make.tapAsync(PLUGIN_NAME, (compilation, callback) => {
			compilation.addModuleChain(
				this.context || compiler.context,
				new PrefetchDependency(this.request),
				(err) => {
					callback(err);
				}
			);
		});
	}
}

module.exports = PrefetchPlugin;