data-frontmatter-customize.md

eleventyNavigation	parent key order Front Matter Data Customize Front Matter Parsing 1
relatedLinks	/docs/data-custom/ Custom Data File Formats

Customize Front Matter Parsing {% addedin "0.9.0" %}

Eleventy uses the gray-matter npm package for parsing front matter. gray-matter allows additional options that aren’t available by default in Eleventy.

Check out the full list of available gray-matter options. By default, Eleventy uses gray-matter’s default options.

{% codetitle ".eleventy.js" %}

module.exports = function(eleventyConfig) {
  eleventyConfig.setFrontMatterParsingOptions({
    /* … */
  });
};

Example: Parse excerpts from content {% addedin "0.9.0" %}

{% codetitle ".eleventy.js" %}

module.exports = function(eleventyConfig) {
  eleventyConfig.setFrontMatterParsingOptions({
    excerpt: true,
    // Optional, default is "---"
    excerpt_separator: "<!-- excerpt -->"
  });
};

Now you can do things like this:

{% codetitle "sample.md" %}

---
title: My page title
---
This is the start of my content and this will be shown as the excerpt.
<!-- excerpt -->
This is a continuation of my content…

Your template’s content will include the excerpt but remove the separator:

This is the start of my content and this will be shown as the excerpt.
This is a continuation of my content…

page.excerpt now holds This is the start of my content and this will be shown as the excerpt.

{% callout "info" %}Don’t want your excerpt included with your content? The unique feature of this configuration is that you can keep your excerpt right at the beginning of your content. You can add a delimiter where you want the excerpt to end and the rest of the content to begin. If you want the excerpt to be separate from the content, make a new key for this and store it separately in your front matter or a data file.{% endcallout %}

Changing where your excerpt is stored

If you don’t want to use page.excerpt to store your excerpt value, then use your own excerpt_alias option (any valid path to Lodash Set will work) like so:

{% codetitle ".eleventy.js" %}

module.exports = function(eleventyConfig) {
  eleventyConfig.setFrontMatterParsingOptions({
    excerpt: true,
    // Eleventy custom option
    // The variable where the excerpt will be stored.
    excerpt_alias: 'my_custom_excerpt'
  });
};

Using excerpt_alias: 'my_custom_excerpt' means that the excerpt will be available in your templates as the my_custom_excerpt variable instead of page.excerpt.

Example: using TOML for front matter parsing {% addedin "0.9.0" %}

While Eleventy does include support for JSON, YAML, and JS front matter out of the box, you may want to add additional formats too.

{% codetitle ".eleventy.js" %}

const toml = require("toml");

module.exports = function(eleventyConfig) {
  eleventyConfig.setFrontMatterParsingOptions({
    engines: {
      toml: toml.parse.bind(toml)
    }
  });
};

For more information, read this example on the gray-matter documentation.

{% callout "warn" %}Windows users: There is an upstream issue with the TOML dependency used here: Expected "\n" but end of input found., logged at Eleventy #586.{% endcallout %}

Now you can use TOML in your front matter like this:

{% codetitle "sample.md" %}

---toml
title = "My page title using TOML"
---
<!doctype html>
<html>
…