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3.1.0

Passthrough File Copy

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If we want to copy additional files that are not Eleventy templates, we use a feature called Passthrough File Copy to tell Eleventy to copy things to our output folder for us.

Configuration API Method

Use a configuration API method to specify files or directories for Eleventy to copy to the output folder.

eleventy.config.js
export default function (eleventyConfig) {
// Output directory: _site

// Copy `img/` to `_site/img/`
eleventyConfig.addPassthroughCopy("img");

// Copy `css/fonts/` to `_site/css/fonts/`
// Keeps the same directory structure.
eleventyConfig.addPassthroughCopy("css/fonts");

// Copy any .jpg file to `_site`, via Glob pattern
// Keeps the same directory structure.
eleventyConfig.addPassthroughCopy("**/*.jpg");
};
module.exports = function (eleventyConfig) {
// Output directory: _site

// Copy `img/` to `_site/img/`
eleventyConfig.addPassthroughCopy("img");

// Copy `css/fonts/` to `_site/css/fonts/`
// Keeps the same directory structure.
eleventyConfig.addPassthroughCopy("css/fonts");

// Copy any .jpg file to `_site`, via Glob pattern
// Keeps the same directory structure.
eleventyConfig.addPassthroughCopy("**/*.jpg");
};
INFO:
Passthrough File Copy entries are relative to the root of your project and not your Eleventy input directory.

If you do not want to maintain the same directory structure, change the output directory.

How Input Directories are Handled

As stated above, passthrough file copy paths are relative to the project root and not the input directory. Because of this, if the passthrough file copy path is inside of your input directory, the input directory will be stripped from the output path.

For example:

  • input directory is src
  • output directory is _site.

If we copy src/img using passthrough file copy, it will copy to _site/img.

eleventy.config.js
export default function (eleventyConfig) {
// Input directory: src
// Output directory: _site

// The following copies to `_site/img`
eleventyConfig.addPassthroughCopy("src/img");
};
module.exports = function (eleventyConfig) {
// Input directory: src
// Output directory: _site

// The following copies to `_site/img`
eleventyConfig.addPassthroughCopy("src/img");
};

Using Globs

In this example, we copy all jpg image files to the output folder, maintaining their directory structure. If you do not want to maintain the same directory structure, change the output directory.

Note that this method is slower than non-glob methods, as it searches the entire directory structure and copies each file individually.

eleventy.config.js
export default function (eleventyConfig) {
// Find and copy any `jpg` files, maintaining directory structure.
eleventyConfig.addPassthroughCopy("**/*.jpg");
};
module.exports = function (eleventyConfig) {
// Find and copy any `jpg` files, maintaining directory structure.
eleventyConfig.addPassthroughCopy("**/*.jpg");
};

With an output directory of _site:

  • img/avatar.jpg will copy to _site/img/avatar.jpg
  • subdir/img/avatar.jpg will copy to _site/subdir/img/avatar.jpg

Copy a file alongside a Template Added in v3.1.0

Use the HTML Relative Passthrough Copy Mode to copy files referenced in any template syntax that outputs to .html. Issue #3573

eleventy.config.js
export default function(eleventyConfig) {
// Relative to the project root directory
eleventyConfig.addPassthroughCopy("content/**/*.mp4", {
mode: "html-relative"
});
}
module.exports = function(eleventyConfig) {
// Relative to the project root directory
eleventyConfig.addPassthroughCopy("content/**/*.mp4", {
mode: "html-relative"
});
}
Full options list
eleventy.config.js
export default async function(eleventyConfig) {
// glob or Array of globs to match for copy
eleventyConfig.addPassthroughCopy("**/*.png", {
mode: "html-relative",
paths: [], // additional fallback directories to look for source files
failOnError: true, // throw an error when a path matches (via `match`) but not found on file system
copyOptions: { dot: false }, // `recursive-copy` copy options
});
}
module.exports = async function(eleventyConfig) {
// glob or Array of globs to match for copy
eleventyConfig.addPassthroughCopy("**/*.png", {
mode: "html-relative",
paths: [], // additional fallback directories to look for source files
failOnError: true, // throw an error when a path matches (via `match`) but not found on file system
copyOptions: { dot: false }, // `recursive-copy` copy options
});
}

Any references that match this glob in a[href], video[src], audio[src], source, img[src], [srcset] and a whole bunch more (via posthtml-urls) will colocate the file alongside your template (reusing any permalink values correctly). If a passthrough copy file is not found to be referenced in an HTML output file, it will not be copied to the output directory.

As a few example paths, with an output directory of _site:

  • <video src="video.mp4"> on template.njk will copy to _site/template/video.mp4 alongside _site/template/index.html.
  • <video src="assets/video.mp4"> on dir/template.njk will copy to _site/dir/template/assets/video.mp4 alongside _site/dir/template/index.html
HTML Relative Copy Mode restrictions
  • dot files are filtered out by default (override by changing the copyOptions.dot: false default, consult the Full options list above)
  • Referenced files must be inside the project’s root directory.
  • Absolute paths are ignored.

Change the Output Directory

Instead of a string, pass in an object of the following structure: { "input": "target" }.

eleventy.config.js
export default function (eleventyConfig) {
// Input directory: src
// Output directory: _site

// Copy `img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ img: "subfolder/img" });

// Copy `src/img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ "src/img": "subfolder/img" });

// Copy `random-folder/img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ "random-folder/img": "subfolder/img" });
};
module.exports = function (eleventyConfig) {
// Input directory: src
// Output directory: _site

// Copy `img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ img: "subfolder/img" });

// Copy `src/img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ "src/img": "subfolder/img" });

// Copy `random-folder/img/` to `_site/subfolder/img`
eleventyConfig.addPassthroughCopy({ "random-folder/img": "subfolder/img" });
};

Using Globs and Output Directories

Note that this method is slower than non-glob methods, as it is searching the entire directory structure and copies each file in Eleventy individually.

eleventy.config.js
export default function (eleventyConfig) {
// Output directory: _site

// Find and copy any `jpg` files in any folder to _site/img
// Does not keep the same directory structure.
eleventyConfig.addPassthroughCopy({ "**/*.jpg": "img" });
};
module.exports = function (eleventyConfig) {
// Output directory: _site

// Find and copy any `jpg` files in any folder to _site/img
// Does not keep the same directory structure.
eleventyConfig.addPassthroughCopy({ "**/*.jpg": "img" });
};

With an output directory of _site:

  • img/avatar.jpg would copy to _site/img/avatar.jpg
  • subdir/img/avatar.jpg would copy to _site/img/avatar.jpg

Emulate Passthrough Copy During --serve Added in v2.0.0

The Eleventy Dev Server includes a great build-performance feature that will emulate passthrough file copy.

Practically speaking, this means that (during --serve only!) files are referenced directly and will not be copied to your output folder. Changes to passthrough file copies will not trigger an Eleventy build but will live reload appropriately in the dev server.

You can enable this behavior in your project using this configuration API method:

eleventy.config.js
export default function (eleventyConfig) {
// the default is "copy"
eleventyConfig.setServerPassthroughCopyBehavior("passthrough");
};
module.exports = function (eleventyConfig) {
// the default is "copy"
eleventyConfig.setServerPassthroughCopyBehavior("passthrough");
};

This behavior will revert to "copy" in your project automatically if:

  1. If you are running Eleventy without --serve (a standard build or via --watch)
  2. You change from the default development server: Eleventy Dev Server (e.g. swap back to Browsersync)
INFO:
For 2.0 canary users, note that this behavior spent a fair bit of time as the default and required opt-out from 2.0.0-canary.12 through 2.0.0-canary.30. It was changed to opt-in in 2.0.0-canary.31.

Passthrough by File Extension

Eleventy, by default, searches for any file in the input directory with a file extension listed in your templateFormats configuration. That means if you’ve listed njk in your templateFormats, we’ll look for any Nunjucks templates (files with the .njk file extension).

If a file format is not recognized by Eleventy as a template file extension, Eleventy will ignore the file. You can modify this behavior by adding supported template formats:

eleventy.config.js
export default function (eleventyConfig) {
eleventyConfig.setTemplateFormats([
"md",
"css", // `css` is not a registered template syntax file extension
]);
};
module.exports = function (eleventyConfig) {
eleventyConfig.setTemplateFormats([
"md",
"css", // `css` is not a registered template syntax file extension
]);
};

In the above code sample css is not currently a recognized Eleventy template, but Eleventy will search for any *.css files inside of the input directory and copy them to output (maintaining the same directory structure).

You might use this for images by adding "jpg", "png", or even "webp".

INFO:
Note that this method is typically slower than the addPassthroughCopy configuration API method above, especially if your project is large and has lots of files.

Advanced Options Added in v2.0.0

Additionally, you can pass additional configuration options to the recursive-copy package. This unlocks the use passthrough file copy with symlinks, transforming or renaming copied files. Here are just a few examples:

eleventy.config.js
export default function (eleventyConfig) {
eleventyConfig.addPassthroughCopy("img", {
expand: true, // expand symbolic links
});

eleventyConfig.addPassthroughCopy({ img: "subfolder/img" }, {
debug: true, // log debug information
});
};
module.exports = function (eleventyConfig) {
eleventyConfig.addPassthroughCopy("img", {
expand: true, // expand symbolic links
});

eleventyConfig.addPassthroughCopy({ img: "subfolder/img" }, {
debug: true, // log debug information
});
};

Review the full list of options on the recursive-copy GitHub repository.


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