mirror of
https://github.com/gohugoio/hugo.git
synced 2024-12-18 13:26:52 -05:00
189 lines
7.5 KiB
Markdown
189 lines
7.5 KiB
Markdown
---
|
|
title: js.Build
|
|
linkTitle: JavaScript building
|
|
description: Bundle, transpile, tree shake, and minify JavaScript resources.
|
|
categories: [asset management]
|
|
keywords: []
|
|
menu:
|
|
docs:
|
|
parent: hugo-pipes
|
|
weight: 60
|
|
weight: 60
|
|
action:
|
|
aliases: []
|
|
returnType: resource.Resource
|
|
signatures: ['js.Build [OPTIONS] RESOURCE']
|
|
---
|
|
|
|
## Usage
|
|
|
|
Any JavaScript resource file can be transpiled and "tree shaken" using `js.Build` which takes for argument either a string for the filepath or a dict of options listed below.
|
|
|
|
### Options
|
|
|
|
targetPath
|
|
: (`string`) If not set, the source path will be used as the base target path.
|
|
Note that the target path's extension may change if the target MIME type is different, e.g. when the source is TypeScript.
|
|
|
|
params {{< new-in "0.96.0" >}}
|
|
: (`map` or `slice`) Params that can be imported as JSON in your JS files, e.g.:
|
|
|
|
```go-html-template
|
|
{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
|
|
```
|
|
And then in your JS file:
|
|
|
|
```js
|
|
import * as params from '@params';
|
|
```
|
|
|
|
Note that this is meant for small data sets, e.g. configuration settings. For larger data, please put/mount the files into `/assets` and import them directly.
|
|
|
|
minify
|
|
: (`bool`) Let `js.Build` handle the minification.
|
|
|
|
inject
|
|
: (`slice`) This option allows you to automatically replace a global variable with an import from another file. The path names must be relative to `assets`. See https://esbuild.github.io/api/#inject
|
|
|
|
shims
|
|
: (`map`) This option allows swapping out a component with another. A common use case is to load dependencies like React from a CDN (with _shims_) when in production, but running with the full bundled `node_modules` dependency during development:
|
|
|
|
```go-html-template
|
|
{{ $shims := dict "react" "js/shims/react.js" "react-dom" "js/shims/react-dom.js" }}
|
|
{{ $js = $js | js.Build dict "shims" $shims }}
|
|
```
|
|
|
|
The _shim_ files may look like these:
|
|
|
|
```js
|
|
// js/shims/react.js
|
|
module.exports = window.React;
|
|
```
|
|
|
|
```js
|
|
// js/shims/react-dom.js
|
|
module.exports = window.ReactDOM;
|
|
```
|
|
|
|
With the above, these imports should work in both scenarios:
|
|
|
|
```js
|
|
import * as React from 'react'
|
|
import * as ReactDOM from 'react-dom';
|
|
```
|
|
|
|
target
|
|
: (`string`) The language target.
|
|
One of: `es5`, `es2015`, `es2016`, `es2017`, `es2018`, `es2019`, `es2020` or `esnext`.
|
|
Default is `esnext`.
|
|
|
|
externals
|
|
: (`slice`) External dependencies. Use this to trim dependencies you know will never be executed. See https://esbuild.github.io/api/#external
|
|
|
|
defines
|
|
: (`map`) Allow to define a set of string replacement to be performed when building. Should be a map where each key is to be replaced by its value.
|
|
|
|
```go-html-template
|
|
{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
|
|
```
|
|
|
|
format
|
|
: (`string`) The output format.
|
|
One of: `iife`, `cjs`, `esm`.
|
|
Default is `iife`, a self-executing function, suitable for inclusion as a `<script>` tag.
|
|
|
|
sourceMap
|
|
: (`string`) Whether to generate `inline` or `external` source maps from esbuild. External source maps will be written to the target with the output file name + ".map". Input source maps can be read from js.Build and node modules and combined into the output source maps. By default, source maps are not created.
|
|
|
|
JSX {{< new-in 0.124.0 >}}
|
|
: (`string`) How to handle/transform JSX syntax. One of: `transform`, `preserve`, `automatic`. Default is `transform`. Notably, the `automatic` transform was introduced in React 17+ and will cause the necessary JSX helper functions to be imported automatically. See https://esbuild.github.io/api/#jsx
|
|
|
|
JSXImportSource {{< new-in 0.124.0 >}}
|
|
: (`string`) Which library to use to automatically import its JSX helper functions from. This only works if `JSX` is set to `automatic`. The specified library needs to be installed through NPM and expose certain exports. See https://esbuild.github.io/api/#jsx-import-source
|
|
|
|
The combination of `JSX` and `JSXImportSource` is helpful if you want to use a non-React JSX library like Preact, e.g.:
|
|
|
|
```go-html-template
|
|
{{ $js := resources.Get "js/main.jsx" | js.Build (dict "JSX" "automatic" "JSXImportSource" "preact") }}
|
|
```
|
|
|
|
With the above, you can use Preact components and JSX without having to manually import `h` and `Fragment` every time:
|
|
|
|
```jsx
|
|
import { render } from 'preact';
|
|
|
|
const App = () => <>Hello world!</>;
|
|
|
|
const container = document.getElementById('app');
|
|
if (container) render(<App />, container);
|
|
```
|
|
|
|
### Import JS code from /assets
|
|
|
|
`js.Build` has full support for the virtual union file system in [Hugo Modules](/hugo-modules/). You can see some simple examples in this [test project](https://github.com/gohugoio/hugoTestProjectJSModImports), but in short this means that you can do this:
|
|
|
|
```js
|
|
import { hello } from 'my/module';
|
|
```
|
|
|
|
And it will resolve to the top-most `index.{js,ts,tsx,jsx}` inside `assets/my/module` in the layered file system.
|
|
|
|
```js
|
|
import { hello3 } from 'my/module/hello3';
|
|
```
|
|
|
|
Will resolve to `hello3.{js,ts,tsx,jsx}` inside `assets/my/module`.
|
|
|
|
Any imports starting with `.` is resolved relative to the current file:
|
|
|
|
```js
|
|
import { hello4 } from './lib';
|
|
```
|
|
|
|
For other files (e.g. `JSON`, `CSS`) you need to use the relative path including any extension, e.g:
|
|
|
|
```js
|
|
import * as data from 'my/module/data.json';
|
|
```
|
|
|
|
Any imports in a file outside `/assets` or that does not resolve to a component inside `/assets` will be resolved by [ESBuild](https://esbuild.github.io/) with the **project directory** as the resolve directory (used as the starting point when looking for `node_modules` etc.). Also see [hugo mod npm pack](/commands/hugo_mod_npm_pack/). If you have any imported npm dependencies in your project, you need to make sure to run `npm install` before you run `hugo`.
|
|
|
|
Also note the new `params` option that can be passed from template to your JS files, e.g.:
|
|
|
|
```go-html-template
|
|
{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
|
|
```
|
|
And then in your JS file:
|
|
|
|
```js
|
|
import * as params from '@params';
|
|
```
|
|
|
|
Hugo will, by default, generate a `assets/jsconfig.json` file that maps the imports. This is useful for navigation/intellisense help inside code editors, but if you don't need/want it, you can [turn it off](/getting-started/configuration/#configure-build).
|
|
|
|
### Include dependencies In package.json / node_modules
|
|
|
|
Any imports in a file outside `/assets` or that does not resolve to a component inside `/assets` will be resolved by [ESBuild](https://esbuild.github.io/) with the **project directory** as the resolve directory (used as the starting point when looking for `node_modules` etc.). Also see [hugo mod npm pack](/commands/hugo_mod_npm_pack/). If you have any imported npm dependencies in your project, you need to make sure to run `npm install` before you run `hugo`.
|
|
|
|
The start directory for resolving npm packages (aka. packages that live inside a `node_modules` folder) is always the main project folder.
|
|
|
|
{{% note %}}
|
|
If you're developing a theme/component that is supposed to be imported and depends on dependencies inside `package.json`, we recommend reading about [hugo mod npm pack](/commands/hugo_mod_npm_pack/), a tool to consolidate all the npm dependencies in a project.
|
|
{{% /note %}}
|
|
|
|
### Examples
|
|
|
|
```go-html-template
|
|
{{ $built := resources.Get "js/index.js" | js.Build "main.js" }}
|
|
```
|
|
|
|
Or with options:
|
|
|
|
```go-html-template
|
|
{{ $externals := slice "react" "react-dom" }}
|
|
{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
|
|
|
|
{{ $opts := dict "targetPath" "main.js" "externals" $externals "defines" $defines }}
|
|
{{ $built := resources.Get "scripts/main.js" | js.Build $opts }}
|
|
<script src="{{ $built.RelPermalink }}" defer></script>
|
|
```
|