Eleventy Plugin Metagen

eleventy-plugin-metagen is a <meta> tag generator for sites built with Eleventy. Generate meta tags for Open Graph and Twitter along with some other useful tags. All of the tags necessary for a baseline social share functionality are included with this plugin along with some additional tags for more custom use cases.

Installation

In your Eleventy project, install the plugin from npm:

npm install eleventy-plugin-metagen

Then add it to your Eleventy Config file:

const metagen = require('eleventy-plugin-metagen');

module.exports = (eleventyConfig) => {
    eleventyConfig.addPlugin(metagen);
};

What does it do?

The plugin turns 11ty shortcodes like this:

{% metagen
    title="Eleventy Plugin Meta Generator",
    desc="An eleventy shortcode for generating meta tags.",
    url="https://tannerdolby.com",
    img="https://tannerdolby.com/images/arch-spiral-large.jpg",
    img_alt="Archimedean Spiral",
    twitter_card_type="summary_large_image",
    twitter_handle="tannerdolby",
    name="Tanner Dolby",
    comments=true
%}

into <meta> tags and other document metadata like this:

<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Eleventy Plugin Meta Generator</title>
<meta name="author" content="Tanner Dolby">
<meta name="description" content="An eleventy shortcode for generating meta tags.">
<meta name="generator" content="eleventy">
<!-- Open Graph -->
<meta property="og:type" content="website">
<meta property="og:locale" content="en_US">
<meta property="og:title" content="Eleventy Plugin Meta Generator">
<meta property="og:description" content="An eleventy shortcode for generating meta tags.">
<meta property="og:url" content="https://tannerdolby.com">
<meta property="og:image" content="https://tannerdolby.com/images/arch-spiral-large.jpg">
<meta property="og:image:alt" content="Archimedean Spiral">
<!-- Twitter -->
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:site" content="@tannerdolby">
<meta name="twitter:creator" content="@tannerdolby">
<meta name="twitter:url" content="https://tannerdolby.com">
<meta name="twitter:title" content="Eleventy Plugin Meta Generator">
<meta name="twitter:description" content="An eleventy shortcode for generating meta tags.">
<meta name="twitter:image" content="https://tannerdolby.com/images/arch-spiral-large.jpg">
<meta name="twitter:image:alt" content="Archimedean Spiral">
<link rel="canonical" href="https://tannerdolby.com">

Custom Usage

For a baseline social share functionality, providing all of the comma separated arguments to metagen shown in the example usage above is recommended. If you want to add more meta tags that are not listed in the example, see parameters for supported tags. You might only need a few <meta> tags instead of the whole set, simply provide the arguments you need and the ones not included won't generate <meta> tags.

Besides the default generated <meta> tags, only the arguments you provide data for will be generated as <meta> tags. This allows you to include some of your own tags alongside metagen if you need. Template variables can be used in the Nunjucks and Liquid shortcode arguments without the curly braces or quotes like title=page.url (Nunjucks) or title (Liquid). More on template variable usage below

Shortcode Default Tags

If atleast one parameter is provided to metagen:

{% metagen 
  comments=true
%}

the default <meta> tags aside from the main Open Graph and Twitter card data are:

<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Open Graph -->
<meta property="og:type" content="website">
<meta property="og:locale" content="en_US">
<!-- Twitter -->
<meta name="twitter:card" content="summary">

The title parameter provides data for <title>. If title is not defined within metagen, the <title> element will not be generated with the above default tags. The same rules apply for name and desc. All other arguments if omitted, will not have meta tags generated.

Using {% metagen %} without any arguments will throw Error: No data was added into the meta generator and return an empty string.

Shorthand Nunjucks Usage

To use the shortcode as a one-liner. You can define an object in frontmatter, global data or another data source with the required key/value pairs and supply the shortcode with a single object parameter.

---
data: 
    title: Eleventy Plugin Add Meta Tags
    desc: An eleventy shortcode for generating meta tags.
    url: https://tannerdolby.com
    img: https://tannerdolby.com/images/arch-spiral-large.jpg
    img_alt: Archimedean Spiral
    twitter_card_type: summary_large_image
    twitter_handle: tannerdolby
    name: Tanner Dolby
---
<head>
  {% metagen data %}
</head>

Use Your Template Data

To make your metadata dynamic, you can use template data as arguments to the shortcode, without quotes or braces:

---
title: Some title
desc: Some description
metadata:
  title: Some other title
  desc: Some other description
url: https://tannerdolby.com
image: https://tannerdolby.com/images/arch-spiral-large.jpg
alt: Archimedean spiral
type: summary_large_image 
twitter: tannerdolby
name: Tanner Dolby
---
{% metagen
    title=title or metadata.title,
    desc=desc or metadata.desc,
    url=url + page.url,
    img=image,
    img_alt=alt,
    twitter_card_type=type,
    twitter_handle=twitter,
    name=name
%}

As a general rule, don't forget your in a templating engine context. Use your variables in the shortcode as you would inside {% var %} tags or {{ var }} without the curly braces like title=var.

Liquid Usage

If you would like to use Liquid (which is the default templating engine in Eleventy). Then utilize the following syntax, to turn shortcodes like this:

---
data: 
    title: Eleventy Plugin Add Meta Tags
    desc: An eleventy shortcode for generating meta tags.
    url: https://tannerdolby.com
    img: https://tannerdolby.com/images/arch-spiral-large.jpg
    img_alt: Archimedean Spiral
    twitter_card_type: summary_large_image
    twitter_handle: tannerdolby
    name: Tanner Dolby
---
<head>
  {% metagen data %}
</head>

The Liquid usage is a bit different as the shortcode expects a single parameter representing an object with key/value pairs. You can define the object in frontmatter like shown above or within global data files.

Shortcode Parameters

A list containing all of the parameters this plugin accepts. If you can't find a parameter that suits your all of your needs, feel free to open an issue so we can get the parameter and/or corresponding meta tag added to the plugin.

title

The content for <title>, <meta name="title">, og:title and twitter:title. If og_title and twitter_title are defined they will override the fields.

name

The content for <meta name="author">.

desc

The content for <meta name="description">, og:description, and twitter:description if og_desc or twitter_desc isn't defined.

generator

The content for <meta name="generator">. The value must be a free-form string that identifies one of the software packages used to generate the document. This value must not be used on pages whose markup is not generated by software, e.g. pages whose markup was written by a user in a text editor.

comments

Display default comments for the Open Graph and Twitter tags.
default: false

og_comment

Display a custom comment for the Open Graph set of tags.
requires: comments: true

type

The content for og:type.
options: article, product
default: website

url

The content for og:url and twitter:url.

site_name

The content for og:site_name.

locale

The locale these tags are marked up in.
default: en_US

og_title

The content for og:title.
default: title

og_desc

The content for og:description.
default: desc

img

The content for og:image and twitter:image.

img_alt

The content for og:image:alt and twitter:image:alt.

img_width

The content for og:image:width.

img_height

The content for og:image:height.

twitter_comment

Display a custom comment for the Twitter set of tags.
requires: comments: true

attr_name

Define attribute name for the Twitter set of meta tags.
options: property
default: name

twitter_card_type

The content for twitter:card.
options: summary_large_image
default: summary

twitter_handle

The content for twitter:site or twitter:creator if twitter_card_type: summary_large_image.

creator_handle

The content for twitter:creator. This tag is used if twitter_card_type: summary_large_image.

twitter_title

The content for twitter:title.
default: title

twitter_desc

The content for twitter:description.
default: desc

Sensible Defaults

• Front-Matter ready with minor edits
• Easy to (un)Comment/Delete based on requirements

---
metadata:
  title: 'edit_me' # <title>, <meta name="title">, og|twitter:title
  name: 'edit_me' # <meta name="author">
  desc: 'edit_me' # <meta name="description">, og|twitter:description
  generator: 'eleventy' # <meta name="generator"> The value must be a free-form string that identifies one of the software packages used to generate the document. This value must not be used on pages whose markup is not generated by software, e.g. pages whose markup was written by a user in a text editor.
  comments: true # Display comments Open Graph & Twitter tags
  # og_comment: '' # custom comment for Open Graph tags. requires: `comments: true`
  # type: 'article|product' # The content for `og:type`. options: article, product; default: `website`
  url: 'edit_me' # og|twitter:url
  site_name: 'edit_me' # og:site_name.
  # locale: '' # locale for marked-up. default: `en_US` 
  # og_title: '' # og:title. default: `title`
  # og_desc: '' # og:description. default: `desc`
  img: 'edit_me' # og|twitter:image
  img_alt: 'edit_me' # og|twitter:image:alt
  # img_width: '' # og:image:width
  # img_height: '' # og:image:height
  # twitter_comment: '' # custom comment for Twitter tags. requires: `comments: true`
  # attr_name: 'property' # Define attribute name for Twitter meta tags. options: `property` default: `name`
  # twitter_card_type: 'summary_large_image' # `twitter:card`. options: `summary_large_image` default: `summary`
  twitter_handle: 'edit_me' # `twitter:site|creator` if `twitter_card_type: summary_large_image`.
  # creator_handle: '' # `twitter:creator`. This tag is used if `twitter_card_type: summary_large_image`.
  # twitter_title: '' # `twitter:title`. default: `title`
  # twitter_desc: '' # `twitter:description`. default: `desc`
---