❤Next Prince Montage

    npm

    Sign UpSign In
    Wondering what’s next for npm?Check out our public roadmap! »

    extract-loader

    5.1.0 • Public • Published

    extract-loader

    webpack loader to extract HTML and CSS from the bundle.

    Dependency Status Build Status Coverage Status

    The extract-loader evaluates the given source code on the fly and returns the result as string. Its main use-case is to resolve urls within HTML and CSS coming from their respective loaders. Use the file-loader to emit the extract-loader's result as separate file.

    import stylesheetUrl from "file-loader!extract-loader!css-loader!main.css";
    // stylesheetUrl will now be the hashed url to the final stylesheet

    The extract-loader works similar to the extract-text-webpack-plugin and the mini-css-extract-plugin and is meant as a lean alternative to it. When evaluating the source code, it provides a fake context which was especially designed to cope with the code generated by the html- or the css-loader. Thus it might not work in other situations.


    Installation

    $ npm install extract-loader --save-dev

    Examples

    Extracting a main.css

    Bundling CSS with webpack has some nice advantages like referencing images and fonts with hashed urls or hot module replacement in development. In production, on the other hand, it's not a good idea to apply your stylesheets depending on JS execution. Rendering may be delayed or even a FOUC might be visible. Thus it's still better to have them as separate files in your final production build.

    With the extract-loader, you are able to reference your main.css as regular entry. The following webpack.config.js shows how to load your styles with the style-loader in development and as separate file in production.

    module.exports = ({ mode }) => {
        const pathToMainCss = require.resolve("./app/main.css");
        const loaders = [{
            loader: "css-loader",
            options: {
                sourceMap: true
            }
        }];
     
        if (mode === "production") {
            loaders.unshift(
                "file-loader",
                "extract-loader"
            );
        } else {
            loaders.unshift("style-loader");
        }
     
        return {
            mode,
            entry: pathToMainCss,
            module: {
                rules: [
                    {
                        test: pathToMainCss,
                        loaders: loaders
                    },
                ]
            }
        };
    };

    Extracting the index.html

    You can even add your index.html as entry and reference your stylesheets from there. In that case, tell the html-loader to also pick up link:href:

    module.exports = ({ mode }) => {
        const pathToMainJs = require.resolve("./app/main.js");
        const pathToIndexHtml = require.resolve("./app/index.html");
     
        return {
            mode,
            entry: [
                pathToMainJs,
                pathToIndexHtml
            ],
            module: {
                rules: [
                    {
                        test: pathToIndexHtml,
                        use: [
                            "file-loader",
                            "extract-loader",
                            {
                                loader: "html-loader",
                                options: {
                                    attrs: ["img:src", "link:href"]
                                }
                            }
                        ]
                    },
                    {
                        test: /\.css$/,
                        use: [
                            "file-loader",
                            "extract-loader",
                            {
                                loader: "css-loader",
                                options: {
                                    sourceMap: true
                                }
                            }
                        ]
                    },
                    {
                        test: /\.jpg$/,
                        use: "file-loader"
                    }
                ]
            }
        };
    }

    turns

    <html>
    <head>
        <link href="main.css" type="text/css" rel="stylesheet">
    </head>
    <body>
        <img src="hi.jpg">
    </body>
    </html>

    into

    <html>
    <head>
        <link href="7c57758b88216530ef48069c2a4c685a.css" type="text/css" rel="stylesheet">
    </head>
    <body>
        <img src="6ac05174ae9b62257ff3aa8be43cf828.jpg">
    </body>
    </html>

    Source Maps

    If you want source maps in your extracted CSS files, you need to set the sourceMap option of the css-loader:

        {
            loader: "css-loader",
            options: {
                sourceMap: true
            }
        }

    Options

    There is currently exactly one option: publicPath. If you are using a relative publicPath in webpack's output options and extracting to a file with the file-loader, you might need this to account for the location of your extracted file. publicPath may be defined as a string or a function that accepts current loader context as single argument.

    Example with publicPath option as a string:

    module.exports = {
        output: {
            path: path.resolve("./dist"),
            publicPath: "dist/"
        },
        module: {
            rules: [
                {
                    test: /\.css$/,
                    use: [
                        {
                            loader: "file-loader",
                            options: {
                                name: "assets/[name].[ext]",
                            },
                        },
                        {
                            loader: "extract-loader",
                            options: {
                                publicPath: "../",
                            }
                        },
                        {
                            loader: "css-loader",
                        },
                    ],
                }
            ]
        }
    };

    Example with publicPath option as a function:

    module.exports = {
        output: {
            path: path.resolve("./dist"),
            publicPath: "dist/"
        },
        module: {
            rules: [
                {
                    test: /\.css$/,
                    use: [
                        {
                            loader: "file-loader",
                            options: {
                                name: "assets/[name].[ext]",
                            },
                        },
                        {
                            loader: "extract-loader",
                            options: {
                                // dynamically return a relative publicPath based on how deep in directory structure the loaded file is in /src/ directory
                                publicPath: (context) => '../'.repeat(path.relative(path.resolve('src'), context.context).split('/').length),
                            }
                        },
                        {
                            loader: "css-loader",
                        },
                    ],
                }
            ]
        }
    };

    You need another option? Then you should think about:


    Contributing

    From opening a bug report to creating a pull request: every contribution is appreciated and welcome. If you're planning to implement a new feature or change the api please create an issue first. This way we can ensure that your precious work is not in vain.

    All pull requests should have 100% test coverage (with notable exceptions) and need to pass all tests.

    • Call npm test to run the unit tests
    • Call npm run coverage to check the test coverage (using istanbul)

    License

    Unlicense

    Sponsors

    Keywords

    Install

    npm i extract-loader

    DownloadsWeekly Downloads

    92,012

    Version

    5.1.0

    License

    Unlicense

    Unpacked Size

    32.1 kB

    Total Files

    5

    Homepage

    github.com/peerigon/extract-loader#readme

    Repository

    Gitgithub.com/peerigon/extract-loader

    Last publish

    Collaborators

    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    Try on RunKit
    Report malware