pad_spa/node_modules/file-loader

file-loader

The file-loader resolves import/require() on a file into a url and emits the file into the output directory.

Getting Started

To begin, you'll need to install file-loader:

$ npm install file-loader --save-dev

Import (or require) the target file(s) in one of the bundle's files:

file.js

import img from './file.png';

Then add the loader to your webpack config. For example:

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        use: [
          {
            loader: 'file-loader',
            options: {},
          },
        ],
      },
    ],
  },
};

And run webpack via your preferred method. This will emit file.png as a file in the output directory (with the specified naming convention, if options are specified to do so) and returns the public URI of the file.

ℹ️ By default the filename of the resulting file is the hash of the file's contents with the original extension of the required resource.

Options

name

Type: String|Function Default: '[hash].[ext]'

Specifies a custom filename template for the target file(s) using the query parameter name. For example, to emit a file from your context directory into the output directory retaining the full directory structure, you might use:

String

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          name: '[path][name].[ext]',
        },
      },
    ],
  },
};

Function

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          name(file) {
            if (process.env.NODE_ENV === 'development') {
              return '[path][name].[ext]';
            }

            return '[hash].[ext]';
          },
        },
      },
    ],
  },
};

ℹ️ By default the path and name you specify will output the file in that same directory, and will also use the same URI path to access the file.

outputPath

Type: String|Function Default: undefined

Specify a filesystem path where the target file(s) will be placed.

String

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          outputPath: 'images',
        },
      },
    ],
  },
};

Function

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          outputPath: (url, resourcePath, context) => {
            // `resourcePath` is original absolute path to asset
            // `context` is directory where stored asset (`rootContext`) or `context` option

            // To get relative path you can use
            // const relativePath = path.relative(context, resourcePath);

            if (/my-custom-image\.png/.test(resourcePath)) {
              return `other_output_path/${url}`;
            }

            if (/images/.test(context)) {
              return `image_output_path/${url}`;
            }

            return `output_path/${url}`;
          },
        },
      },
    ],
  },
};

publicPath

Type: String|Function Default: __webpack_public_path__

Specifies a custom public path for the target file(s).

String

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          publicPath: 'assets',
        },
      },
    ],
  },
};

Function

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          publicPath: (url, resourcePath, context) => {
            // `resourcePath` is original absolute path to asset
            // `context` is directory where stored asset (`rootContext`) or `context` option

            // To get relative path you can use
            // const relativePath = path.relative(context, resourcePath);

            if (/my-custom-image\.png/.test(resourcePath)) {
              return `other_public_path/${url}`;
            }

            if (/images/.test(context)) {
              return `image_output_path/${url}`;
            }

            return `public_path/${url}`;
          },
        },
      },
    ],
  },
};

context

Type: String Default: context

Specifies a custom file context.

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          context: 'project',
        },
      },
    ],
  },
};

emitFile

Type: Boolean Default: true

If true, emits a file (writes a file to the filesystem). If false, the loader will return a public URI but will not emit the file. It is often useful to disable this option for server-side packages.

file.js

// bundle file
import img from './file.png';

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.css$/,
        loader: 'file-loader',
        options: {
          emitFile: false,
        },
      },
    ],
  },
};

regExp

Type: RegExp Default: undefined

Specifies a Regular Expression to one or many parts of the target file path. The capture groups can be reused in the name property using [N] placeholder.

file.js

import img from './customer01/file.png';

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          regExp: /\/([a-z0-9]+)\/[a-z0-9]+\.png$/,
          name: '[1]-[name].[ext]',
        },
      },
    ],
  },
};

ℹ️ If [0] is used, it will be replaced by the entire tested string, whereas [1] will contain the first capturing parenthesis of your regex and so on...

Placeholders

Full information about placeholders you can find here.

[ext]

Type: String Default: file.extname

The file extension of the target file/resource.

[name]

Type: String Default: file.basename

The basename of the file/resource.

[path]

Type: String Default: file.directory

The path of the resource relative to the webpack/config context.

[folder]

Type: String Default: file.folder

The folder of the resource is in.

[emoji]

Type: String Default: undefined

A random emoji representation of content.

[emoji:<length>]

Type: String Default: undefined

Same as above, but with a customizable number of emojis

[hash]

Type: String Default: md5

Specifies the hash method to use for hashing the file content.

[<hashType>:hash:<digestType>:<length>]

Type: String

The hash of options.content (Buffer) (by default it's the hex digest of the hash).

digestType

Type: String Default: 'hex'

The digest that the hash function should use. Valid values include: base26, base32, base36, base49, base52, base58, base62, base64, and hex.

hashType

Type: String Default: 'md5'

The type of hash that the has function should use. Valid values include: md5, sha1, sha256, and sha512.

length

Type: Number Default: undefined

Users may also specify a length for the computed hash.

[N]

Type: String Default: undefined

The n-th match obtained from matching the current file name against the regExp.

Examples

The following examples show how one might use file-loader and what the result would be.

file.js

import png from './image.png';

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          name: 'dirname/[hash].[ext]',
        },
      },
    ],
  },
};

Result:

# result
dirname/0dcbbaa701328ae351f.png

---

file.js

import png from './image.png';

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          name: '[sha512:hash:base64:7].[ext]',
        },
      },
    ],
  },
};

Result:

# result
gdyb21L.png

---

file.js

import png from './path/to/file.png';

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/,
        loader: 'file-loader',
        options: {
          name: '[path][name].[ext]?[hash]',
        },
      },
    ],
  },
};

Result:

# result
path/to/file.png?e43b20c069c4a01867c31e98cbce33c9

Contributing

Please take a moment to read our contributing guidelines if you haven't yet done so.

CONTRIBUTING

License

MIT