webpack/lib/Entrypoint.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
	Author Tobias Koppers @sokra
*/

"use strict";

const ChunkGroup = require("./ChunkGroup");

/** @typedef {import("../declarations/WebpackOptions").EntryDescriptionNormalized} EntryDescription */
/** @typedef {import("./Chunk")} Chunk */

/** @typedef {{ name?: string } & Omit<EntryDescription, "import">} EntryOptions */

/**
 * Entrypoint serves as an encapsulation primitive for chunks that are
 * a part of a single ChunkGroup. They represent all bundles that need to be loaded for a
 * single instance of a page. Multi-page application architectures will typically yield multiple Entrypoint objects
 * inside of the compilation, whereas a Single Page App may only contain one with many lazy-loaded chunks.
 */
class Entrypoint extends ChunkGroup {
	/**
	 * Creates an instance of Entrypoint.
	 * @param {EntryOptions | string} entryOptions the options for the entrypoint (or name)
	 * @param {boolean=} initial false, when the entrypoint is not initial loaded
	 */
	constructor(entryOptions, initial = true) {
		if (typeof entryOptions === "string") {
			entryOptions = { name: entryOptions };
		}
		super({
			name: entryOptions.name
		});
		this.options = entryOptions;
		/** @type {Chunk=} */
		this._runtimeChunk = undefined;
		/** @type {Chunk=} */
		this._entrypointChunk = undefined;
		/** @type {boolean} */
		this._initial = initial;
	}

	/**
	 * @returns {boolean} true, when this chunk group will be loaded on initial page load
	 */
	isInitial() {
		return this._initial;
	}

	/**
	 * Sets the runtimeChunk for an entrypoint.
	 * @param {Chunk} chunk the chunk being set as the runtime chunk.
	 * @returns {void}
	 */
	setRuntimeChunk(chunk) {
		this._runtimeChunk = chunk;
	}

	/**
	 * Fetches the chunk reference containing the webpack bootstrap code
	 * @returns {Chunk | null} returns the runtime chunk or null if there is none
	 */
	getRuntimeChunk() {
		if (this._runtimeChunk) return this._runtimeChunk;
		for (const parent of this.parentsIterable) {
			if (parent instanceof Entrypoint) return parent.getRuntimeChunk();
		}
		return null;
	}

	/**
	 * Sets the chunk with the entrypoint modules for an entrypoint.
	 * @param {Chunk} chunk the chunk being set as the entrypoint chunk.
	 * @returns {void}
	 */
	setEntrypointChunk(chunk) {
		this._entrypointChunk = chunk;
	}

	/**
	 * Returns the chunk which contains the entrypoint modules
	 * (or at least the execution of them)
	 * @returns {Chunk} chunk
	 */
	getEntrypointChunk() {
		return this._entrypointChunk;
	}

	/**
	 * @param {Chunk} oldChunk chunk to be replaced
	 * @param {Chunk} newChunk New chunk that will be replaced with
	 * @returns {boolean} returns true if the replacement was successful
	 */
	replaceChunk(oldChunk, newChunk) {
		if (this._runtimeChunk === oldChunk) this._runtimeChunk = newChunk;
		if (this._entrypointChunk === oldChunk) this._entrypointChunk = newChunk;
		return super.replaceChunk(oldChunk, newChunk);
	}
}

module.exports = Entrypoint;