webpack/lib/schemes/DataUriPlugin.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 NormalModule = require("../NormalModule");
const { URIRegEx, decodeDataURI } = require("../util/dataURL");

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

const PLUGIN_NAME = "DataUriPlugin";

class DataUriPlugin {
	/**
	 * 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 }) => {
				normalModuleFactory.hooks.resolveForScheme
					.for("data")
					.tap(PLUGIN_NAME, (resourceData, resolveData) => {
						const match = URIRegEx.exec(resourceData.resource);
						if (match) {
							resourceData.data.mimetype = match[1] || "";
							resourceData.data.parameters = match[2] || "";
							resourceData.data.encoding = /** @type {"base64" | false} */ (
								match[3] || false
							);
							resourceData.data.encodedContent = match[4] || "";
						}
						// Inherit the issuer's resolution context so any nested
						// dependencies discovered while parsing the data URI's body
						// (e.g. `url(...)` / `@import` inside an inline CSS data
						// URI) resolve relative to where the URI was referenced
						// from, instead of against the synthetic `data:.../` path
						// that `getContext("data:…")` would otherwise infer.
						if (
							resourceData.context === undefined &&
							resolveData.context !== undefined
						) {
							resourceData.context = resolveData.context;
						}
					});

				NormalModule.getCompilationHooks(compilation)
					.readResourceForScheme.for("data")
					.tap(PLUGIN_NAME, (resource) => decodeDataURI(resource));
			}
		);
	}
}

module.exports = DataUriPlugin;