webpack/lib/ContextReplacementPlugin.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 ContextElementDependency = require("./dependencies/ContextElementDependency");
const { join } = require("./util/fs");

class ContextReplacementPlugin {
	constructor(
		resourceRegExp,
		newContentResource,
		newContentRecursive,
		newContentRegExp
	) {
		this.resourceRegExp = resourceRegExp;

		if (typeof newContentResource === "function") {
			this.newContentCallback = newContentResource;
		} else if (
			typeof newContentResource === "string" &&
			typeof newContentRecursive === "object"
		) {
			this.newContentResource = newContentResource;
			this.newContentCreateContextMap = (fs, callback) => {
				callback(null, newContentRecursive);
			};
		} else if (
			typeof newContentResource === "string" &&
			typeof newContentRecursive === "function"
		) {
			this.newContentResource = newContentResource;
			this.newContentCreateContextMap = newContentRecursive;
		} else {
			if (typeof newContentResource !== "string") {
				newContentRegExp = newContentRecursive;
				newContentRecursive = newContentResource;
				newContentResource = undefined;
			}
			if (typeof newContentRecursive !== "boolean") {
				newContentRegExp = newContentRecursive;
				newContentRecursive = undefined;
			}
			this.newContentResource = newContentResource;
			this.newContentRecursive = newContentRecursive;
			this.newContentRegExp = newContentRegExp;
		}
	}

	apply(compiler) {
		const resourceRegExp = this.resourceRegExp;
		const newContentCallback = this.newContentCallback;
		const newContentResource = this.newContentResource;
		const newContentRecursive = this.newContentRecursive;
		const newContentRegExp = this.newContentRegExp;
		const newContentCreateContextMap = this.newContentCreateContextMap;

		compiler.hooks.contextModuleFactory.tap("ContextReplacementPlugin", cmf => {
			cmf.hooks.beforeResolve.tap("ContextReplacementPlugin", result => {
				if (!result) return;
				if (resourceRegExp.test(result.request)) {
					if (newContentResource !== undefined) {
						result.request = newContentResource;
					}
					if (newContentRecursive !== undefined) {
						result.recursive = newContentRecursive;
					}
					if (newContentRegExp !== undefined) {
						result.regExp = newContentRegExp;
					}
					if (typeof newContentCallback === "function") {
						newContentCallback(result);
					} else {
						for (const d of result.dependencies) {
							if (d.critical) d.critical = false;
						}
					}
				}
				return result;
			});
			cmf.hooks.afterResolve.tap("ContextReplacementPlugin", result => {
				if (!result) return;
				if (resourceRegExp.test(result.resource)) {
					if (newContentResource !== undefined) {
						if (
							newContentResource.startsWith("/") ||
							(newContentResource.length > 1 && newContentResource[1] === ":")
						) {
							result.resource = newContentResource;
						} else {
							result.resource = join(
								compiler.inputFileSystem,
								result.resource,
								newContentResource
							);
						}
					}
					if (newContentRecursive !== undefined) {
						result.recursive = newContentRecursive;
					}
					if (newContentRegExp !== undefined) {
						result.regExp = newContentRegExp;
					}
					if (typeof newContentCreateContextMap === "function") {
						result.resolveDependencies =
							createResolveDependenciesFromContextMap(
								newContentCreateContextMap
							);
					}
					if (typeof newContentCallback === "function") {
						const origResource = result.resource;
						newContentCallback(result);
						if (
							result.resource !== origResource &&
							!result.resource.startsWith("/") &&
							(result.resource.length <= 1 || result.resource[1] !== ":")
						) {
							// When the function changed it to an relative path
							result.resource = join(
								compiler.inputFileSystem,
								origResource,
								result.resource
							);
						}
					} else {
						for (const d of result.dependencies) {
							if (d.critical) d.critical = false;
						}
					}
				}
				return result;
			});
		});
	}
}

const createResolveDependenciesFromContextMap = createContextMap => {
	const resolveDependenciesFromContextMap = (fs, options, callback) => {
		createContextMap(fs, (err, map) => {
			if (err) return callback(err);
			const dependencies = Object.keys(map).map(key => {
				return new ContextElementDependency(
					map[key] + options.resourceQuery + options.resourceFragment,
					key,
					options.category,
					options.referencedExports
				);
			});
			callback(null, dependencies);
		});
	};
	return resolveDependenciesFromContextMap;
};

module.exports = ContextReplacementPlugin;