webpack/lib/SetVarTemplatePlugin.js

78 lines
2.0 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const { ConcatSource } = require("webpack-sources");
const RuntimeGlobals = require("./RuntimeGlobals");
const JavascriptModulesPlugin = require("./javascript/JavascriptModulesPlugin");
/** @typedef {import("./Compiler")} Compiler */
class SetVarTemplatePlugin {
/**
* @param {string} varExpression the accessor where the library is exported
* @param {boolean} copyObject specify copying the exports
*/
constructor(varExpression, copyObject) {
/** @type {string} */
this.varExpression = varExpression;
/** @type {boolean} */
this.copyObject = copyObject;
}
/**
* @param {Compiler} compiler the compiler instance
* @returns {void}
*/
apply(compiler) {
compiler.hooks.thisCompilation.tap("SetVarTemplatePlugin", compilation => {
compilation.hooks.additionalTreeRuntimeRequirements.tap(
"LibraryTemplatePlugin",
(chunk, set) => {
set.add(RuntimeGlobals.returnExportsFromRuntime);
}
);
const hooks = JavascriptModulesPlugin.getCompilationHooks(compilation);
hooks.render.tap(
"SetVarTemplatePlugin",
(source, { chunk, chunkGraph }) => {
if (chunkGraph.getNumberOfEntryModules(chunk) === 0) return source;
const varExpression = compilation.getPath(this.varExpression, {
chunk
});
if (this.copyObject) {
return new ConcatSource(
`(function(e, a) { for(var i in a) e[i] = a[i]; }(${varExpression}, `,
source,
"))"
);
} else {
const prefix = `${varExpression} =\n`;
return new ConcatSource(prefix, source);
}
}
);
hooks.chunkHash.tap(
"SetVarTemplatePlugin",
(chunk, hash, { chunkGraph }) => {
if (chunkGraph.getNumberOfEntryModules(chunk) === 0) return;
hash.update("set var");
const varExpression = compilation.getPath(this.varExpression, {
chunk
});
hash.update(`${varExpression}`);
hash.update(`${this.copyObject}`);
}
);
});
}
}
module.exports = SetVarTemplatePlugin;