useref

v1.4.4

Parse build blocks in HTML files to replace references

build blocks build comments replace scripts link ref

useref

Parse build blocks in HTML files to replace references

Extracted from the grunt plugin grunt-useref.

Installation

npm install useref

Usage

var useref = require('useref');
var result = useref(inputHtml);
// result = [ replacedHtml, { type: { path: { 'assets': [ replacedFiles] }}} ]

Blocks are expressed as:

<!-- 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>
<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:

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>
<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:

<!-- 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:

<!--[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.

<!-- build:import components -->
<link rel="import" href="/bower_components/some/path"></link>
<!-- endbuild -->

With

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

<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 and laravel asset and elixir links in twig or blade or html or php.

<!-- 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.

<!-- 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:

<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

License

npm i useref

Source Code

github.com/jonkemp/usere...

Homepage

github.com/jonkemp/useref#re...

Metadata

MIT
>=4
Jonathan Kemp
released 3/27/2022

Downloads

Maintainers

jonkemp