Adds CSS to the DOM by injecting a <style>
tag
npm install style-loader --save-dev
require("style-loader!raw-loader!./file.css");
// => add rules in file.css to document
It's recommended to combine it with the css-loader
: require("style-loader!css-loader!./file.css")
.
It's also possible to add a URL instead of a CSS string:
require("style-loader/url!file-loader!./file.css");
// => add a <link rel="stylesheet"> to file.css to document
(experimental)
When using local scope CSS the module exports the generated identifiers:
var style = require("style-loader!css-loader!./file.css");
style.placeholder1 === "z849f98ca812bc0d099a43e0f90184"
var style = require("style-loader/useable!css-loader!./file.css");
style.use(); // = style.ref();
style.unuse(); // = style.unref();
Styles are not added on require
, but instead on call to use
/ref
. Styles are removed from page if unuse
/unref
is called exactly as often as use
/ref
.
Note: Behavior is undefined when unuse
/unref
is called more often than use
/ref
. Don't do that.
By default, the style-loader appends <style>
elements to the end of the style target, which is the <head>
tag of the page unless specified by insertInto
. This will cause CSS created by the loader to take priority over CSS already present in the target. To insert style elements at the beginning of the target, set this query parameter to 'top', e.g. require('../style.css?insertAt=top')
.
By default, the style-loader inserts the <style>
elements into the <head>
tag of the page. If you want the tags to be inserted somewhere else, e.g. into a ShadowRoot, you can specify a CSS selector for that element here, e.g. require('../style.css?insertInto=#host::shadow>#root')
.
If defined, the style-loader will re-use a single <style>
element, instead of adding/removing individual elements for each required module. Note: this option is on by default in IE9, which has strict limitations on the number of style tags allowed on a page. You can enable or disable it with the singleton query parameter (?singleton
or ?-singleton
).
If convertToAbsoluteUrls and sourceMaps are both enabled, relative urls will be converted to absolute urls right before the css is injected into the page. This resolves an issue where relative resources fail to load when source maps are enabled. You can enable it with the convertToAbsoluteUrls query parameter (?convertToAbsoluteUrls
).
If defined, style-loader will attach given attributes with their values on <style>
/ <link>
element.
Usage:
require('style-loader?{attrs:{id: "style-tag-id"}}!style.css');
// will create style tag <style id="style-tag-id">
Usage in url
mode:
require('style-loader/url?{attrs:{prop: "value"}}!file-loader!style.css')
// will create link tag <link rel="stylesheet" type="text/css" href="[path]/style.css" prop="value">
This setting is primarily used as a workaround for css clashes when using one or more DllPlugin's. base
allows you to prevent either the app's css (or DllPlugin2's css) from overwriting DllPlugin1's css by specifying a css module id base which is greater than the range used by DllPlugin1 e.g.:
- webpack.dll1.config.js
{
test: /\.css$/,
use: [
'style-loader',
'css-loader'
]
}
- webpack.dll2.config.js
{
test: /\.css$/,
use: [
{ loader: 'style-loader', options: { base: 1000 } },
'css-loader'
]
}
- webpack.app.config.js
{
test: /\.css$/,
use: [
{ loader: 'style-loader', options: { base: 2000 } },
'css-loader'
]
}
By convention the reference-counted API should be bound to .useable.css
and the simple API to .css
(similar to other file types, i.e. .useable.less
and .less
).
So the recommended configuration for webpack is:
{
module: {
rules: [
{
test: /\.css$/,
use: [
{ loader: "style-loader" },
{ loader: "css-loader" },
],
},
{
test: /\.useable\.css$/,
use: [
{
loader: "style-loader/useable"
},
{ loader: "css-loader" },
],
},
],
},
}
Note about source maps support and assets referenced with url
: when style loader is used with ?sourceMap option, the CSS modules will be generated as Blob
s, so relative paths don't work (they would be relative to chrome:blob
or chrome:devtools
). In order for assets to maintain correct paths setting output.publicPath
property of webpack configuration must be set, so that absolute paths are generated. Alternatively you can enable the convertToAbsoluteUrls
option mentioned above.
Don't hesitate to create a pull request. Every contribution is appreciated. In development you can start the tests by calling npm test
.
Tobias Koppers |
Kees Kluskens |
MIT