Title: Block Metadata
Author: leoloso
Published: <strong>අගෝස්තු 22, 2019</strong>
Last modified: අප්‍රේල් 15, 2020

---

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![](https://ps.w.org/block-metadata/assets/banner-772x250.jpg?rev=2143662)

This plugin **hasn’t been tested with the latest 3 major releases of WordPress**.
It may no longer be maintained or supported and may have compatibility issues when
used with more recent versions of WordPress.

![](https://ps.w.org/block-metadata/assets/icon-256x256.jpg?rev=2143662)

# Block Metadata

 By [leoloso](https://profiles.wordpress.org/leoloso/)

[Download](https://downloads.wordpress.org/plugin/block-metadata.1.0.7.zip)

 * [Details](https://si.wordpress.org/plugins/block-metadata/#description)
 * [Reviews](https://si.wordpress.org/plugins/block-metadata/#reviews)
 *  [Installation](https://si.wordpress.org/plugins/block-metadata/#installation)
 * [Development](https://si.wordpress.org/plugins/block-metadata/#developers)

 [Support](https://wordpress.org/support/plugin/block-metadata/)

## Description

This plugin helps convert WordPress into a manager of our digital content, to publish
it in different mediums or platforms: not just the website, but also email, iOS/
Android apps, home-assistants (like Amazon Alexa) and others.

It does this by extracting the metadata from all Gutenberg blocks inside of a blog
post. Because each Gutenberg block stores its own content and properties, these 
ones can be extracted as metadata and exported through a JSON object, accessible
through a REST API endpoint, to feed any application on any platform.

The plugin makes the following REST API endpoints available:

 * /wp-json/block-metadata/v1/metadata/{POST_ID}: Extract all metadata from all 
   Gutenberg blocks in a blog post with id {POST_ID}, converted to medium-agnostic(
   eg: removing all non-semantic HTML tags)
 * /wp-json/block-metadata/v1/data/{POST_ID}: Extract all data from all Gutenberg
   blocks in a blog post with id {POST_ID}, as originally stored in the block by
   Gutenberg (eg: containing HTML code)

Demonstration:

 * [Blog post](https://nextapi.getpop.org/posts/cope-with-wordpress-post-demo-containing-plenty-of-blocks/)
 * [Blog post’s Gutenberg blocks](https://nextapi.getpop.org/wp-json/block-metadata/v1/data/1499)
 * [Blog post’s medium-agnostic metadata](https://nextapi.getpop.org/wp-json/block-metadata/v1/metadata/1499)

#### How does it work?

This plugin is based on the strategy called “Create Once, Publish Everywhere” (also
called “COPE”), which reduces the amount of work needed to publish our content into
different mediums by establishing a single source of truth for all content.

Having content that works everywhere is not a trivial task, since each medium will
have its own requirements. For instance, whereas HTML is valid for printing content
for the web, this language is not valid for an iOS/Android app; similarly, we can
add classes to our HTML for the web, but these must be converted to styles for email.

The solution is to separate form from content: The presentation and the meaning 
of the content must be decoupled, and only the meaning is used as the single source
of truth. The presentation can then be added in another layer, specific to the selected
medium. For instance, given the following piece of HTML code, the `<p>` is an HTML
tag which applies mostly for the web, and attribute class=”align-center” is presentation(
placing an element “on the center” makes sense for a screen-based medium, but not
for an audio-based one such as Amazon Alexa):

    ```
    <p class="align-center">Hello world!</p>
    ```

Hence, this piece of content cannot be used as a single source of truth, and it 
must be converted into a format which separates the meaning from the presentation,
such as the following piece of JSON code:

    ```
    {
      content: "Hello world!",
      placement: "center",
      type: "paragraph"
    }
    ```

This piece of code can be used as a single source of truth for content, since from
it we can recreate once again the HTML code to use for the web, and procure an appropriate
format for other mediums.

#### Supported Gutenberg blocks

This plugin attempts to extract the metadata for all Gutenberg blocks shipped in
WordPress core; support for additional blocks, such as from plugins, can be added
through hooks. Not all Gutenberg blocks can be supported (for instance, because 
they may only work for the web, or only make sense when applied to screen-based 
mediums, among other reasons).

The following WordPress core blocks are currently not supported:

 * `"core/columns"`
 * `"core/column"`
 * `"core/cover"`
 * `"core/html"`
 * `"core/table"`
 * `"core/button"`
 * `"core/media-text"`

The following Gutenberg blocks are supported, and this plugin extracts their metadata:

 * `"core/paragraph"`
 * `"core/image"`
 * `"core-embed/youtube"` (all other `"core-embed"` blocks can also be extracted,
   but must be implemented through a hook)
 * `"core/heading"`
 * `"core/gallery"`
 * `"core/list"`
 * `"core/audio"`
 * `"core/file"`
 * `"core/video"`
 * `"core/code"`
 * `"core/preformatted"`
 * `"core/quote"`
 * `"core/pullquote"`
 * `"core/verse"`

#### Extracting metadata for additional blocks

We can extend this plugin to extract the metadata for additional blocks, such as
those shipped through plugins. To do this, simply add a hook for filter `"Leoloso\
BlockMetadata\Metadata::blockMeta"` (located in function `get_block_metadata($block_data)`
from class `Metadata` in file `block-metadata/src/Metadata.php`). The attributes
that must be extracted must be decided on a block type by block type basis:

    ```
    add_filter("Leoloso\BlockMetadata\Metadata::blockMeta", "extract_additional_block_metadata", 10, 3);
    function extract_additional_block_metadata($blockMeta, $blockName, $block)
    {
      if ($blockName == "my-plugin/my-block-name") {
        return array(
          "property1" => $block["property1"],
          "property2" => $block["property2"]
        );
      }

      return $blockMeta;
    }
    ```

#### Further references

 * [Inspiration for the plugin](https://leoloso.com/posts/my-1st-wp-plugin/)
 * [Slides from presentation “COPE with WordPress”](https://slides.com/leoloso/cope-with-wp)(
   from WordCamp Singapore 2019), explaining how the plugin works

#### Contributing / Reporting issues

Please head over to the project’s [GitHub repo](https://github.com/leoloso/block-metadata)
for contributing, reporting issues or making suggestions, and others.

_Banner image [designed by Freepik](https://www.freepik.com)_

## Installation

 1. Make sure pretty permalinks are enabled (eg: “/%postname%/”)
 2. Install and activate this plugin

## Reviews

![](https://secure.gravatar.com/avatar/74b1b74e8bc084caf433ac34d86bd4fcd2485d7804e5c869d6652ee19020226d?
s=60&d=retro&r=g)

### 󠀁[useful plugin](https://wordpress.org/support/topic/useful-plugin-573/)󠁿

 [ivan so](https://profiles.wordpress.org/cyis100/) නොවැම්බර් 2, 2019

This plugin is useful to give my Gutenberg content into meta data so i could use
it to integrate with other system as this plugin already parse the attribute.

 [ Read all 1 review ](https://wordpress.org/support/plugin/block-metadata/reviews/)

## Contributors & Developers

“Block Metadata” is open source software. The following people have contributed 
to this plugin.

Contributors

 *   [ leoloso ](https://profiles.wordpress.org/leoloso/)

[Translate “Block Metadata” into your language.](https://translate.wordpress.org/projects/wp-plugins/block-metadata)

### Interested in development?

[Browse the code](https://plugins.trac.wordpress.org/browser/block-metadata/), check
out the [SVN repository](https://plugins.svn.wordpress.org/block-metadata/), or 
subscribe to the [development log](https://plugins.trac.wordpress.org/log/block-metadata/)
by [RSS](https://plugins.trac.wordpress.org/log/block-metadata/?limit=100&mode=stop_on_copy&format=rss).

## Meta

 *  Version **1.0.7**
 *  Last updated **වසර 6ක් ago**
 *  Active installations **10+**
 *  WordPress version ** 5.0 or higher **
 *  Tested up to **5.4.19**
 *  PHP version ** 5.6 or higher **
 *  Language
 * [English (US)](https://wordpress.org/plugins/block-metadata/)
 * Tags
 * [api](https://si.wordpress.org/plugins/tags/api/)[block](https://si.wordpress.org/plugins/tags/block/)
   [content](https://si.wordpress.org/plugins/tags/content/)[gutenberg](https://si.wordpress.org/plugins/tags/gutenberg/)
   [metadata](https://si.wordpress.org/plugins/tags/metadata/)
 *  [Advanced View](https://si.wordpress.org/plugins/block-metadata/advanced/)

## Ratings

 5 out of 5 stars.

 *  [  1 5-star review     ](https://wordpress.org/support/plugin/block-metadata/reviews/?filter=5)
 *  [  0 4-star reviews     ](https://wordpress.org/support/plugin/block-metadata/reviews/?filter=4)
 *  [  0 3-star reviews     ](https://wordpress.org/support/plugin/block-metadata/reviews/?filter=3)
 *  [  0 2-star reviews     ](https://wordpress.org/support/plugin/block-metadata/reviews/?filter=2)
 *  [  0 1-star reviews     ](https://wordpress.org/support/plugin/block-metadata/reviews/?filter=1)

[Your review](https://wordpress.org/support/plugin/block-metadata/reviews/#new-post)

[See all reviews](https://wordpress.org/support/plugin/block-metadata/reviews/)

## Contributors

 *   [ leoloso ](https://profiles.wordpress.org/leoloso/)

## Support

Got something to say? Need help?

 [View support forum](https://wordpress.org/support/plugin/block-metadata/)