The imports loader allows you to use modules that depend on specific global variables.
This is useful for third-party modules that rely on global variables like $
or this
being the window
object.
The imports loader can add the necessary require('whatever')
calls, so those modules work with webpack.
For further hints on compatibility issues, check out Shimming of the official docs.
Warning
By default loader generate ES module named syntax.
Warning
Be careful, existing imports (import
/require
) in the original code and importing new values can cause failure.
To begin, you'll need to install imports-loader
:
npm install imports-loader --save-dev
or
yarn add -D imports-loader
or
pnpm add -D imports-loader
Given you have this file:
example.js
$("img").doSomeAwesomeJqueryPluginStuff();
Then you can inject the jquery
value into the module by configuring the imports-loader
using two approaches.
The |
or %20
(space) allow to separate the syntax
, moduleName
, name
and alias
of import.
The documentation and syntax examples can be read here.
Warning
%20
is space in a query string, because you can't use spaces in URLs
// Alternative syntax:
//
// import myLib from 'imports-loader?imports=default%20jquery%20$!./example.js';
//
// `%20` is space in a query string, equivalently `default jquery $`
import myLib from "imports-loader?imports=default|jquery|$!./example.js";
// Adds the following code to the beginning of example.js:
//
// import $ from "jquery";
//
// ...
// Code
// ...
import myLib from "imports-loader?imports=default|jquery|$,angular!./example.js";
// `|` is separator in a query string, equivalently `default|jquery|$` and `angular`
// Adds the following code to the beginning of example.js:
//
// import $ from "jquery";
// import angular from "angular";
//
// ...
// Code
// ...
import myLib from "imports-loader?imports=named|library|myMethod,angular!./example.js";
// `|` is separator in a query string, equivalently `named|library|myMethod` and `angular`
// Adds the following code to the beginning of example.js:
//
// import { myMethod } from "library";
// import angular from "angular";
//
// ...
// Code
// ...
const myLib = require(
`imports-loader?type=commonjs&imports=single|jquery|$,angular!./example.js`,
);
// `|` is separator in a query string, equivalently `single|jquery|$` and `angular`
// Adds the following code to the beginning of example.js:
//
// var $ = require("jquery");
// var angular = require("angular");
//
// ...
// Code
// ...
const myLib = require(
`imports-loader?type=commonjs&imports=single|myLib|myMethod&wrapper=window&!./example.js`,
);
// `|` is separator in a query string, equivalently `single|myLib|myMethod` and `angular`
// Adds the following code to the example.js:
//
// const myMethod = require('myLib');
//
// (function () {
// ...
// Code
// ...
// }.call(window));
import myLib from "imports-loader?additionalCode=var%20myVariable%20=%20false;!./example.js";
// Adds the following code to the beginning of example.js:
//
// var myVariable = false;
//
// ...
// Code
// ...
webpack.config.js
module.exports = {
module: {
rules: [
{
// You can use `regexp`
// test: /example\.js$/
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: [
"default jquery $",
"default lib_2 lib_2_default",
"named lib_3 lib2_method_1",
"named lib_3 lib2_method_2 lib_2_method_2_short",
"namespace lib_4 my_namespace",
"side-effects lib_5",
{
syntax: "default",
moduleName: "angular",
name: "angular",
},
],
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
import lib_2_default from "lib_2";
import { lib2_method_1, lib2_method_2 as lib_2_method_2_short } from "lib_3";
import * as my_namespace from "lib_4";
import "lib_5";
import angular from "angular";
And run webpack
via your preferred method.
Type:
type type = string;
Default: module
Format of generated exports.
Possible values - commonjs
(CommonJS module syntax) and module
(ES module syntax).
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
loader: "imports-loader",
options: {
syntax: "default",
type: "commonjs",
imports: "Foo",
},
},
],
},
};
Generate output:
var Foo = require("Foo");
// ...
// Code
// ...
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
loader: "imports-loader",
options: {
type: "module",
imports: "Foo",
},
},
],
},
};
Generate output:
import Foo from "Foo";
// ...
// Code
// ...
Type:
type imports =
| string
| {
syntax:
| "default"
| "named"
| "namespace"
| "side-effects"
| "single"
| "multiple"
| "pure";
moduleName: string;
name: string;
alias: string;
}
| Array<
| string
| {
syntax:
| "default"
| "named"
| "namespace"
| "side-effects"
| "single"
| "multiple"
| "pure";
moduleName: string;
name: string;
alias: string;
}
>;
Default: undefined
List of imports.
Allows to use a string to describe an export.
The |
or %20
(space) allow to separate the syntax
, moduleName
, name
and alias
of import.
String syntax - [[syntax] [moduleName] [name] [alias]]
or [[syntax]|[moduleName]|[name]|[alias]]
, where:
-
[syntax]
(may be omitted):- if
type
ismodule
- can bedefault
,named
,namespace
orside-effects
, the default value isdefault
. - if
type
iscommonjs
- can besingle
,multiple
orpure
, the default value issingle
.
- if
-
[moduleName]
- name of an imported module (required) -
[name]
- name of an imported value (required) -
[alias]
- alias of an imported value (may be omitted)
Examples:
If type module
:
[Foo]
- generatesimport Foo from "Foo";
.[default Foo]
- generatesimport Foo from "Foo";
.[default ./my-lib Foo]
- generatesimport Foo from "./my-lib";
.[named Foo FooA]
- generatesimport { FooA } from "Foo";
.[named Foo FooA Bar]
- generatesimport { FooA as Bar } from "Foo";
.[namespace Foo FooA]
- generatesimport * as FooA from "Foo";
.[side-effects Foo]
- generatesimport "Foo";
.
If type commonjs
:
[Foo]
- generatesconst Foo = require("Foo");
.[single Foo]
- generatesconst Foo = require("Foo");
.[single ./my-lib Foo]
- generatesconst Foo = require("./my-lib");
.[multiple Foo FooA Bar]
- generatesconst { FooA: Bar } = require("Foo");
.[pure Foo]
- generatesrequire("Foo");
.
Warning
You need to set type: "commonjs"
to use single
, multiple
and pure
syntaxes.
Warning
Aliases can't be used together with default
, namespace
, side-effects
, single
and pure
syntaxes.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("./path/to/example.js"),
loader: "imports-loader",
options: {
imports: "default lib myName",
},
},
],
},
};
Generate output:
import myName from "lib";
// ...
// Code
// ...
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("./path/to/example.js"),
loader: "imports-loader",
options: {
type: "commonjs",
imports: "single lib myName",
},
},
],
},
};
Generate output:
var myName = require("lib");
// ...
// Code
// ...
Allows to use an object to describe an import.
Properties:
-
syntax
:- if
type
ismodule
- can bedefault
,named
,namespace
orside-effects
- if
type
iscommonjs
- can besingle
,multiple
orpure
- if
-
moduleName
- name of an imported module (required) -
name
- name of an imported value (required) -
alias
- alias of an imported value (may be omitted)
Warning
Alias can't be used together with default
, namespace
, side-effects
, single
and pure
syntaxes.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
syntax: "named",
moduleName: "lib_2",
name: "lib2_method_2",
alias: "lib_2_method_2_alias",
},
},
},
],
},
],
},
};
Generate output:
import { lib2_method_2 as lib_2_method_2_alias } from "lib_2";
// ...
// Code
// ...
Allow to specify multiple imports.
Each item can be a string
or an object
.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: [
{
moduleName: "angular",
},
{
syntax: "default",
moduleName: "jquery",
name: "$",
},
"default lib_2 lib_2_default",
"named lib_2 lib2_method_1",
"named lib_2 lib2_method_2 lib_2_method_2_alias",
"namespace lib_3 lib_3_all",
"side-effects lib_4",
],
},
},
],
},
],
},
};
Generate output:
import angular from "angular";
import $ from "jquery";
import lib_2_default from "lib_2";
import { lib2_method_1, lib2_method_2 as lib_2_method_2_alias } from "lib_2";
import * as lib_3_all from "lib_3";
import "lib_4";
// ...
// Code
// ...
Type:
type wrapper =
| boolean
| string
| {
thisArg: string;
args: Record<string, string> | Array<string>;
};
Default: undefined
Closes the module code in a function with a given thisArg
and args
((function () { ... }).call();
).
Warning
Do not use this option if source code contains ES module import(s)
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
wrapper: true,
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
(function () {
// ...
// Code
// ...
}).call();
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
wrapper: "window",
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
(function () {
// ...
// Code
// ...
}).call(window);
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
wrapper: {
thisArg: "window",
args: ["myVariable", "myOtherVariable"],
},
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
(function (myVariable, myOtherVariable) {
// ...
// Code
// ...
}).call(window, myVariable, myOtherVariable);
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
wrapper: {
thisArg: "window",
args: {
myVariable: "var1",
myOtherVariable: "var2",
},
},
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
(function (var1, var2) {
// ...
// Code
// ...
}).call(window, myVariable, myOtherVariable);
Type:
type additionalCode = string;
Default: undefined
Adds custom code as a preamble before the module's code.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
additionalCode: "var myVariable = false;",
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
var myVariable = false;
// ...
// Code
// ...
webpack.config.js
module.exports = {
module: {
rules: [
{
test: require.resolve("example.js"),
use: [
{
loader: "imports-loader",
options: {
imports: {
moduleName: "jquery",
name: "$",
},
additionalCode:
"var define = false; /* Disable AMD for misbehaving libraries */",
},
},
],
},
],
},
};
Generate output:
import $ from "jquery";
var define = false; /* Disable AMD for misbehaving libraries */
// ...
// Code
// ...
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