webpack/lib/css/CssServerStylesRuntimeModule.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 Alexander Akait @alexander-akait
*/

"use strict";

const RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const Template = require("../Template");

/** @import Compilation from "../Compilation" */

class CssServerStylesRuntimeModule extends RuntimeModule {
	constructor() {
		super("css server styles");
	}

	/**
	 * Returns true, if the runtime module should get it's own scope.
	 * When false, `generate()` must emit complete statements ending with `;`
	 * so a following runtime IIFE is not parsed as a call (ASI).
	 * @returns {boolean} true, if the runtime module should get it's own scope
	 */
	shouldIsolate() {
		return false;
	}

	/**
	 * Generates runtime code for this runtime module.
	 * @returns {string | null} runtime code
	 */
	generate() {
		const compilation = /** @type {Compilation} */ (this.compilation);
		const { runtimeTemplate } = compilation;
		const cst = runtimeTemplate.renderConst();

		return Template.asString([
			`${RuntimeGlobals.getCssServerStyles} = ${runtimeTemplate.basicFunction(
				"",
				[
					`${cst} registry = ${runtimeTemplate.cssServerStyleRegistry()};`,
					'var css = "";',
					// keys are string-prefixed at the write site, so this yields
					// insertion order rather than ascending numeric module id order
					"for (var key in registry) css += registry[key];",
					"return css;"
				]
			)};`
		]);
	}
}

module.exports = CssServerStylesRuntimeModule;