CasperSecurity
<div align="center">
<img width="200" height="200" src="https://worldvectorlogo.com/logos/html5.svg" alt="html-loader">
<a href="https://github.com/webpack/webpack">
<img width="200" height="200" vspace="" hspace="25" src="https://webpack.js.org/assets/icon-square-big.svg" alt="webpack">
</a>
</div>
[![npm][npm]][npm-url]
[![node][node]][node-url]
[![deps][deps]][deps-url]
[![tests][tests]][tests-url]
[![coverage][cover]][cover-url]
[![chat][chat]][chat-url]
[![size][size]][size-url]
# html-loader
Exports HTML as string. HTML is minimized when the compiler demands.
## Getting Started
To begin, you'll need to install `html-loader`:
```console
npm install --save-dev html-loader
```
Then add the plugin to your `webpack` config. For example:
**file.js**
```js
import html from './file.html';
```
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
},
],
},
};
```
## Options
| Name | Type | Default | Description |
| :---------------------------------: | :-----------------: | :------------------------------------------: | :----------------------------------------------- |
| **[`attributes`](#attributes)** | `{Boolean\|Object}` | `true` | Enables/Disables attributes handling |
| **[`preprocessor`](#preprocessor)** | `{Function}` | `undefined` | Allows pre-processing of content before handling |
| **[`minimize`](#minimize)** | `{Boolean\|Object}` | `true` in production mode, otherwise `false` | Tell `html-loader` to minimize HTML |
| **[`esModule`](#esmodule)** | `{Boolean}` | `false` | Use ES modules syntax |
### `attributes`
Type: `Boolean|Object`
Default: `true`
By default every loadable attributes (for example - `<img src="image.png">`) is imported (`const img = require('./image.png')` or `import img from "./image.png""`).
You may need to specify loaders for images in your configuration (recommended `file-loader` or `url-loader`).
Supported tags and attributes:
- the `src` attribute of the `audio` tag
- the `src` attribute of the `embed` tag
- the `src` attribute of the `img` tag
- the `srcset` attribute of the `img` tag
- the `src` attribute of the `input` tag
- the `href` attribute of the `link` tag (only for stylesheets)
- the `data` attribute of the `object` tag
- the `src` attribute of the `script` tag
- the `href` attribute of the `script` tag
- the `xlink:href` attribute of the `script` tag
- the `src` attribute of the `source` tag
- the `srcset` attribute of the `source` tag
- the `src` attribute of the `track` tag
- the `poster` attribute of the `video` tag
- the `src` attribute of the `video` tag
- the `xlink:href` attribute of the `image` tag
- the `href` attribute of the `image` tag
- the `xlink:href` attribute of the `use` tag
- the `href` attribute of the `use` tag
#### `Boolean`
The `true` value enables processing of all default elements and attributes, the `false` disable processing of all attributes.
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
// Disables attributes processing
attributes: false,
},
},
],
},
};
```
#### `Object`
Allows you to specify which tags and attributes to process, filter them, filter urls and process sources starts with `/`.
For example:
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
attributes: {
list: [
// All default supported tags and attributes
'...',
{
tag: 'img',
attribute: 'data-src',
type: 'src',
},
{
tag: 'img',
attribute: 'data-srcset',
type: 'srcset',
},
],
urlFilter: (attribute, value, resourcePath) => {
// The `attribute` argument contains a name of the HTML attribute.
// The `value` argument contains a value of the HTML attribute.
// The `resourcePath` argument contains a path to the loaded HTML file.
if (/example\.pdf$/.test(value)) {
return false;
}
return true;
},
root: '.',
},
},
},
],
},
};
```
#### `list`
Type: `Array`
Default: [supported tags and attributes](#attributes).
Allows to setup which tags and attributes to process and how, and the ability to filter some of them.
Using `...` syntax allows you to extend [default supported tags and attributes](#attributes).
For example:
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
attributes: {
list: [
// All default supported tags and attributes
'...',
{
tag: 'img',
attribute: 'data-src',
type: 'src',
},
{
tag: 'img',
attribute: 'data-srcset',
type: 'srcset',
},
{
// Tag name
tag: 'link',
// Attribute name
attribute: 'href',
// Type of processing, can be `src` or `scrset`
type: 'src',
// Allow to filter some attributes
filter: (tag, attribute, attributes, resourcePath) => {
// The `tag` argument contains a name of the HTML tag.
// The `attribute` argument contains a name of the HTML attribute.
// The `attributes` argument contains all attributes of the tag.
// The `resourcePath` argument contains a path to the loaded HTML file.
if (/my-html\.html$/.test(resourcePath)) {
return false;
}
if (!/stylesheet/i.test(attributes.rel)) {
return false;
}
if (
attributes.type &&
attributes.type.trim().toLowerCase() !== 'text/css'
) {
return false;
}
return true;
},
},
],
},
},
},
],
},
};
```
If the tag name is not specified it will process all the tags.
> You can use your custom filter to specify html elements to be processed.
For example:
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
attributes: {
list: [
{
// Attribute name
attribute: 'src',
// Type of processing, can be `src` or `scrset`
type: 'src',
// Allow to filter some attributes (optional)
filter: (tag, attribute, attributes, resourcePath) => {
// The `tag` argument contains a name of the HTML tag.
// The `attribute` argument contains a name of the HTML attribute.
// The `attributes` argument contains all attributes of the tag.
// The `resourcePath` argument contains a path to the loaded HTML file.
// choose all HTML tags except img tag
return tag.toLowerCase() !== 'img';
},
},
],
},
},
},
],
},
};
```
#### `urlFilter`
Type: `Function`
Default: `undefined`
Allow to filter urls. All filtered urls will not be resolved (left in the code as they were written).
All non requestable sources (for example `<img src="javascript:void(0)">`) do not handle by default.
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
attributes: {
urlFilter: (attribute, value, resourcePath) => {
// The `attribute` argument contains a name of the HTML attribute.
// The `value` argument contains a value of the HTML attribute.
// The `resourcePath` argument contains a path to the loaded HTML file.
if (/example\.pdf$/.test(value)) {
return false;
}
return true;
},
},
},
},
],
},
};
```
#### `root`
Type: `String`
Default: `undefined`
For urls that start with a `/`, the default behavior is to not translate them.
If a `root` query parameter is set, however, it will be prepended to the url and then translated.
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
attributes: {
root: '.',
},
},
},
],
},
};
```
### `preprocessor`
Type: `Function`
Default: `undefined`
Allows pre-processing of content before handling.
> ⚠ You should always return valid HTML
**file.hbs**
```hbs
<div>
<p>{{firstname}} {{lastname}}</p>
<img src="image.png" alt="alt" />
<div>
```
#### `Function`
You can set the `preprocessor` option as a `Function` instance.
**webpack.config.js**
```js
const Handlebars = require('handlebars');
module.exports = {
module: {
rules: [
{
test: /\.hbs$/i,
loader: 'html-loader',
options: {
preprocessor: (content, loaderContext) => {
let result;
try {
result = Handlebars.compile(content)({
firstname: 'Value',
lastname: 'OtherValue',
});
} catch (error) {
loaderContext.emitError(error);
return content;
}
return result;
},
},
},
],
},
};
```
You can also set the `preprocessor` option as an asynchronous function instance.
For example:
**webpack.config.js**
```js
const Handlebars = require('handlebars');
module.exports = {
module: {
rules: [
{
test: /\.hbs$/i,
loader: 'html-loader',
options: {
preprocessor: async (content, loaderContext) => {
let result;
try {
result = await Handlebars.compile(content)({
firstname: 'Value',
lastname: 'OtherValue',
});
} catch (error) {
await loaderContext.emitError(error);
return content;
}
return result;
},
},
},
],
},
};
```
### `minimize`
Type: `Boolean|Object`
Default: `true` in production mode, otherwise `false`
Tell `html-loader` to minimize HTML.
#### `Boolean`
The enabled rules for minimizing by default are the following ones:
```js
({
caseSensitive: true,
collapseWhitespace: true,
conservativeCollapse: true,
keepClosingSlash: true,
minifyCSS: true,
minifyJS: true,
removeComments: true,
removeRedundantAttributes: true,
removeScriptTypeAttributes: true,
removeStyleLinkTypeAttributes: true,
});
```
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
minimize: true,
},
},
],
},
};
```
#### `Object`
**webpack.config.js**
See [html-minifier-terser](https://github.com/DanielRuf/html-minifier-terser)'s documentation for more information on the available options.
The rules can be disabled using the following options in your `webpack.conf.js`
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
minimize: {
removeComments: false,
collapseWhitespace: false,
},
},
},
],
},
};
```
### `esModule`
Type: `Boolean`
Default: `false`
By default, `html-loader` generates JS modules that use the CommonJS modules syntax.
There are some cases in which using ES modules is beneficial, like in the case of [module concatenation](https://webpack.js.org/plugins/module-concatenation-plugin/) and [tree shaking](https://webpack.js.org/guides/tree-shaking/).
You can enable a ES module syntax using:
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
loader: 'html-loader',
options: {
esModule: true,
},
},
],
},
};
```
## Examples
### CDN
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{ test: /\.jpg$/, loader: 'file-loader' },
{ test: /\.png$/, loader: 'url-loader' },
],
},
output: {
publicPath: 'http://cdn.example.com/[hash]/',
},
};
```
**file.html**
```html
<img src="image.jpg" data-src="image2x.png" />
```
**index.js**
```js
require('html-loader!./file.html');
// => '<img src="http://cdn.example.com/49eba9f/a992ca.jpg" data-src="image2x.png">'
```
```js
require('html-loader?{"attributes":{"list":[{"tag":"img","attribute":"data-src","type":"src"}]}}!./file.html');
// => '<img src="image.jpg" data-src="data:image/png;base64,..." >'
```
```js
require('html-loader?{"attributes":{"list":[{"tag":"img","attribute":"src","type":"src"},{"tag":"img","attribute":"data-src","type":"src"}]}}!./file.html');
// => '<img src="http://cdn.example.com/49eba9f/a992ca.jpg" data-src="data:image/png;base64,..." >'
```
```js
require('html-loader?-attributes!./file.html');
// => '<img src="image.jpg" data-src="image2x.png" >'
```
> :warning: `-attributes` sets `attributes: false`.
### Process `script` and `link` tags
**script.file.js**
```js
console.log(document);
```
**style.file.css**
```css
a {
color: red;
}
```
**file.html**
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Title of the document</title>
<link rel="stylesheet" type="text/css" href="./style.file.css" />
</head>
<body>
Content of the document......
<script src="./script.file.js"></script>
</body>
</html>
```
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
use: ['file-loader?name=[name].[ext]', 'extract-loader', 'html-loader'],
},
{
test: /\.js$/i,
exclude: /\.file.js$/i,
loader: 'babel-loader',
},
{
test: /\.file.js$/i,
loader: 'file-loader',
},
{
test: /\.css$/i,
exclude: /\.file.css$/i,
loader: 'css-loader',
},
{
test: /\.file.css$/i,
loader: 'file-loader',
},
],
},
};
```
### 'Root-relative' URLs
With the same configuration as in the CDN example:
**file.html**
```html
<img src="/image.jpg" />
```
**scripts.js**
```js
require('html-loader!./file.html');
// => '<img src="/image.jpg">'
```
**other-scripts.js**
```js
require('html-loader?{"attributes":{"root":"."}}!./file.html');
// => '<img src="http://cdn.example.com/49eba9f/a992ca.jpg">'
```
### Templating
You can use any template system. Below is an example for [handlebars](https://handlebarsjs.com/).
**file.hbs**
```hbs
<div>
<p>{{firstname}} {{lastname}}</p>
<img src="image.png" alt="alt" />
<div>
```
**webpack.config.js**
```js
const Handlebars = require('handlebars');
module.exports = {
module: {
rules: [
{
test: /\.hbs$/i,
loader: 'html-loader',
options: {
preprocessor: (content, loaderContext) => {
let result;
try {
result = Handlebars.compile(content)({
firstname: 'Value',
lastname: 'OtherValue',
});
} catch (error) {
loaderContext.emitError(error);
return content;
}
return result;
},
},
},
],
},
};
```
### PostHTML
You can use [PostHTML](https://github.com/posthtml/posthtml) without any additional loaders.
**file.html**
```html
<img src="image.jpg" />
```
**webpack.config.js**
```js
const posthtml = require('posthtml');
const posthtmlWebp = require('posthtml-webp');
module.exports = {
module: {
rules: [
{
test: /\.hbs$/i,
loader: 'html-loader',
options: {
preprocessor: (content, loaderContext) => {
let result;
try {
result = posthtml().use(plugin).process(content, { sync: true });
} catch (error) {
loaderContext.emitError(error);
return content;
}
return result.html;
},
},
},
],
},
};
```
### Export into HTML files
A very common scenario is exporting the HTML into their own _.html_ file, to
serve them directly instead of injecting with javascript. This can be achieved
with a combination of 3 loaders:
- [file-loader](https://github.com/webpack/file-loader)
- [extract-loader](https://github.com/peerigon/extract-loader)
- html-loader
The html-loader will parse the URLs, require the images and everything you
expect. The extract loader will parse the javascript back into a proper html
file, ensuring images are required and point to proper path, and the file loader
will write the _.html_ file for you. Example:
**webpack.config.js**
```js
module.exports = {
module: {
rules: [
{
test: /\.html$/i,
use: ['file-loader?name=[name].[ext]', 'extract-loader', 'html-loader'],
},
],
},
};
```
## Contributing
Please take a moment to read our contributing guidelines if you haven't yet done so.
[CONTRIBUTING](./.github/CONTRIBUTING.md)
## License
[MIT](./LICENSE)
[npm]: https://img.shields.io/npm/v/html-loader.svg
[npm-url]: https://npmjs.com/package/html-loader
[node]: https://img.shields.io/node/v/html-loader.svg
[node-url]: https://nodejs.org
[deps]: https://david-dm.org/webpack-contrib/html-loader.svg
[deps-url]: https://david-dm.org/webpack-contrib/html-loader
[tests]: https://github.com/webpack-contrib/html-loader/workflows/html-loader/badge.svg
[tests-url]: https://github.com/webpack-contrib/html-loader/actions
[cover]: https://codecov.io/gh/webpack-contrib/html-loader/branch/master/graph/badge.svg
[cover-url]: https://codecov.io/gh/webpack-contrib/html-loader
[chat]: https://img.shields.io/badge/gitter-webpack%2Fwebpack-brightgreen.svg
[chat-url]: https://gitter.im/webpack/webpack
[size]: https://packagephobia.now.sh/badge?p=html-loader
[size-url]: https://packagephobia.now.sh/result?p=html-loader