%PDF-
%PDF-
Mini Shell
Mini Shell
# useref  [](https://coveralls.io/github/jonkemp/useref?branch=master)
[](https://nodei.co/npm/useref/)
> Parse build blocks in HTML files to replace references
Extracted from the grunt plugin [grunt-useref](https://github.com/pajtai/grunt-useref).
## Installation
```
npm install useref
```
## Usage
```js
var useref = require('useref');
var result = useref(inputHtml);
// result = [ replacedHtml, { type: { path: { 'assets': [ replacedFiles] }}} ]
```
Blocks are expressed as:
```html
<!-- build:<type>(alternate search path) <path> <parameters> -->
... HTML Markup, list of script / link tags.
<!-- endbuild -->
```
- **type**: either `js`, `css` or `remove`
- **alternate search path**: (optional) By default the input files are relative to the treated file. Alternate search path allows one to change that
- **path**: the file path of the optimized file, the target output
- **parameters**: extra parameters that should be added to the tag. By default `rel="stylesheet"` attribute is added to css link tag, your can overwrite it by passing your own rel parameter, e.g. `rel="preload"`
An example of this in completed form can be seen below:
```html
<html>
<head>
<!-- build:css css/combined.css -->
<link href="css/one.css" rel="stylesheet">
<link href="css/two.css" rel="stylesheet">
<!-- endbuild -->
</head>
<body>
<!-- build:js scripts/combined.js -->
<script type="text/javascript" src="scripts/one.js"></script>
<script type="text/javascript" src="scripts/two.js"></script>
<!-- endbuild -->
<!-- build:js scripts/async.js async data-foo="bar" -->
<script type="text/javascript" src="scripts/three.js"></script>
<script type="text/javascript" src="scripts/four.js"></script>
<!-- endbuild -->
</body>
</html>
```
The module would be used with the above sample HTML as follows:
```js
var result = useref(sampleHtml);
// [
// resultHtml,
// {
// css: {
// 'css/combined.css': {
// 'assets': [ 'css/one.css', 'css/two.css' ]
// }
// },
// js: {
// 'scripts/combined.js': {
// 'assets': [ 'scripts/one.js', 'scripts/two.js' ]
// },
// 'scripts/async.js': {
// 'assets': [ 'scripts/three.js', 'scripts/four.js' ]
// }
// }
// }
// ]
```
The resulting HTML would be:
```html
<html>
<head>
<link rel="stylesheet" href="css/combined.css"/>
</head>
<body>
<script src="scripts/combined.js"></script>
<script src="scripts/async.js" async data-foo="bar" ></script>
</body>
</html>
```
## IE Conditional Comments
Internet Explorer Conditional Comments are preserved. The code below:
```html
<!-- build:js scripts/combined.js -->
<!--[if lt IE 9]>
<script type="text/javascript" src="scripts/this.js"></script>
<script type="text/javascript" src="scripts/that.js"></script>
<![endif]-->
<!-- endbuild -->
```
Results in:
```html
<!--[if lt IE 9]>
<script src="scripts/combined.js"></script>
<![endif]-->
```
### Custom blocks
Sometimes you need a bit more. If you would like to do custom processing, this is possible with a custom block, as demonstrated below.
```html
<!-- build:import components -->
<link rel="import" href="/bower_components/some/path"></link>
<!-- endbuild -->
```
With
```js
var useref = require('useref');
var result = useref(inputHtml, {
// each property corresponds to any blocks with the same name, e.g. "build:import"
import: function (content, target, options, alternateSearchPath) {
// do something with `content` and return the desired HTML to replace the block content
return content.replace('bower_components', target);
}
});
```
Becomes
```html
<link rel="import" href="/components/some/path"></link>
```
The handler function gets the following arguments:
- *content* (String): The content of the custom use block
- *target* (String): The "path" value of the use block definition
- *options* (String): The extra attributes from the use block definition, the developer can parse as JSON or do whatever they want with it
- *alternateSearchPath* (String): The alternate search path that can be used to maintain a coherent interface with standard handlers
Include a handler for each custom block type.
### Symfony Twig and Laravel 5 Blade assets
Works with the [symfony2 assetic](http://symfony.com/doc/current/cookbook/assetic/asset_management.html) and [laravel asset](https://laravel.com/docs/5.1/helpers#method-asset) and [elixir](https://laravel.com/docs/5.2/elixir#versioning-and-cache-busting) links in twig or blade or html or php.
```html
<!-- build:js scripts/combined.js -->
<script src="{{ asset('symfony/js/script.js') }}"></script>
<script src="{{ elixir('laravel/js/script.js') }}"></script>
<!-- endbuild -->
```
### Options
#### options.noconcat
Type: `Boolean`
Default: `false`
Strips out build comments but leaves the rest of the block intact without replacing any tags.
```html
<!-- build:js scripts/combined.js -->
<script type="text/javascript" src="scripts/this.js"></script>
<script type="text/javascript" src="scripts/that.js"></script>
<!-- endbuild -->
```
Results in:
```html
<script type="text/javascript" src="scripts/this.js"></script>
<script type="text/javascript" src="scripts/that.js"></script>
```
#### options.parseSourcePath
Type: `Function`
Return: The path to the source file
Function to parse the source path out of a script or style element.
The function gets the following arguments:
- *tag* (String): The html script or style tag
- *type*: (String): The type e.g. `js`, `css`
#### options.transformTargetPath
Type: `Function`
Return: The transformed path to the target file
Function to transform the target file path.
The function gets the following arguments:
- *target* (String): The path to the target file
- *type*: (String): The type e.g. `js`, `css`
## Contributing
See the [CONTRIBUTING Guidelines](https://github.com/jonkemp/useref/blob/master/CONTRIBUTING.md)
## License
MIT © [Jonathan Kemp](http://jonkemp.com)
Zerion Mini Shell 1.0