postcss-import

What is postcss-import?

The postcss-import npm package is a plugin for PostCSS that allows you to import local files, node modules, or web_modules into your CSS files. It can be used to modularize your CSS and help manage large stylesheets by splitting them into smaller, more maintainable pieces.

What are postcss-import's main functionalities?

Importing local files

Allows you to import a local CSS file into another CSS file. This is useful for splitting your CSS into smaller, more manageable files.

@import 'local-file.css';

Importing node modules

Enables you to import CSS from a node module installed in your project's node_modules directory. This is useful for including third-party stylesheets in your project.

@import 'npm-module-name';

Importing from web_modules

Allows you to import CSS from web_modules, which can be useful if you are using a package manager that supports this feature, like Snowpack.

@import 'web-module-name';

Customizing import paths

Lets you customize the paths where postcss-import looks for CSS files to import. This is helpful when you have a specific directory structure and want to keep your imports clean and relative to those paths.

postcss([ require('postcss-import')({ path: ['src/css', 'src/styles'] }) ]);

Other packages similar to postcss-import

postcss-easy-import

A wrapper around postcss-import that adds glob pattern importing and other features. It is similar to postcss-import but with additional options for ease of use.

postcss-partial-import

Another PostCSS plugin that allows you to import partials. It is similar to postcss-import but with a focus on partials and includes features like prefixing and extension omission.

postcss-advanced-variables

While not solely focused on importing, this plugin extends CSS with variables, conditionals, and iterators that can be imported from other files. It offers a different set of features compared to postcss-import, which is focused on importing CSS files.

README

postcss-import

PostCSS plugin to transform @import rules by inlining content.

This plugin can consume local files, node modules or bower packages. To resolve path of an @import rule, it can look into root directory (by default process.cwd()), node_modules, web_modules, bower_components or local modules. You can also provide manually multiples paths where to look at.

Notes:

• This plugin works great with postcss-url plugin, which will allow you to adjust assets url() (or even inline them) after inlining imported files.
• In order to optimize output, this plugin will only import a file once on a given scope (root, media query...). Tests are made from the path & the content of imported files (using a hash table). If this behavior is not what you want, look at skipDuplicates option

Installation

$ npm install postcss-import

Usage

If your stylesheets are not in the same place where you run postcss (process.cwd()), you will need to use from option to make relative imports work from input dirname.

// dependencies
var fs = require("fs")
var postcss = require("postcss")
var atImport = require("postcss-import")

// css to be processed
var css = fs.readFileSync("css/input.css", "utf8")

// process css
var output = postcss()
  .use(atImport())
  .process(css, {
    // `from` option is required so relative import can work from input dirname
    from: "css/input.css"
  })
  .css

console.log(output)

Using this input.css:

/* can consume `node_modules`, `web_modules`, `bower_components` or local modules */
@import "cssrecipes-defaults"; /* == @import "./node_modules/cssrecipes-defaults/index.css"; */

@import "normalize.css/normalize"; /* == @import "./bower_components/normalize.css/normalize.css"; */

@import "css/foo.css"; /* relative to stylesheets/ according to `from` option above */

@import "css/bar.css" (min-width: 25em);

body {
  background: black;
}

will give you:

/* ... content of ./node_modules/my-css-on-npm/index.css */

/* ... content of ./bower_components/my-css-on-bower/index.css */

/* ... content of foo.css */

@media (min-width: 25em) {
/* ... content of bar.css */
}

body {
  background: black;
}

Checkout tests for more examples.

Options

root

Type: String
Default: process.cwd()

Define the root where to resolve path (eg: place where node_modules and bower_components are). Should not be used that much.

path

Type: String|Array
Default: process.cwd() or dirname of the postcss from

A string or an array of paths in where to look for files.
Note: nested @import will additionally benefit of the relative dirname of imported files.

async

Type: Boolean
Default: false

Allow to enable PostCSS async API usage. Before enabling this, check that your runner allow async usage. Note: this is not enabling async fs read yet.

transform

Type: Function
Default: null

A function to transform the content of imported files. Take one argument (file content) & should return the modified content.

plugins

Type: Array
Default: undefined

An array of plugins to be applied on each imported file.

encoding

Type: String
Default: utf8

Use if your CSS is encoded in anything other than UTF-8.

onImport

Type: Function
Default: null

Function called after the import process. Take one argument (array of imported files).

glob

Type: Boolean
Default: false

Set to true if you want @import rules to parse glob patterns.

resolve

Type: Function
Default: null

You can overwrite the default path resolving way by setting this option, using the resolve.sync(id, opts) signature that resolve.sync has.

skipDuplicates

Type: Boolean
Default: true

By default, similar files (based on the same content) are being skipped. It's to optimize output and skip similar files like normalize.css for example. If this behavior is not what you want, just set this option to false to disable it.

Example with some options

var postcss = require("postcss")
var atImport = require("postcss-import")

var css = postcss()
  .use(atImport({
    path: ["src/css"]
    transform: require("css-whitespace")
  }))
  .process(cssString)
  .css

---

Contributing

Work on a branch, install dev-dependencies, respect coding style & run tests before submitting a bug fix or a feature.

$ git clone https://github.com/postcss/postcss-import.git
$ git checkout -b patch-1
$ npm install
$ npm test

Changelog

License