Parse build blocks in HTML files to replace references
Extracted from the grunt plugin grunt-useref.
npm install useref
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,cssorremove - 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>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]-->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.
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 -->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>See the CONTRIBUTING Guidelines
MIT © Jonathan Kemp