@wordpress/blocks

“Block” is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage. The idea combines concepts of what in WordPress today we achieve with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience.

For more context, refer to What Are Little Blocks Made Of? from the Make WordPress Design blog.

Learn how to create your first block for the WordPress block editor. From setting up your development environment, tools, and getting comfortable with the new development model, this tutorial covers all you need to know to get started with creating blocks.

Installation

Install the module

npm install @wordpress/blocks --save

This package assumes that your code will run in an ES2015+ environment. If you’re using an environment that has limited or no support for such language features and APIs, you should include the polyfill shipped in @wordpress/babel-preset-default in your code.

API

cloneBlock

Given a block object, returns a copy of the block object, optionally merging new attributes and/or replacing its inner blocks.

Parameters

  • block Object: Block instance.
  • mergeAttributes Object: Block attributes.
  • newInnerBlocks ?Array: Nested blocks.

Returns

  • Object: A cloned block.

createBlock

Returns a block object given its type and attributes.

Parameters

  • name string: Block name.
  • attributes Object: Block attributes.
  • innerBlocks ?Array: Nested blocks.

Returns

  • Object: Block object.

createBlocksFromInnerBlocksTemplate

Given an array of InnerBlocks templates or Block Objects, returns an array of created Blocks from them. It handles the case of having InnerBlocks as Blocks by converting them to the proper format to continue recursively.

Parameters

  • innerBlocksOrTemplate Array: Nested blocks or InnerBlocks templates.

Returns

  • Object[]: Array of Block objects.

doBlocksMatchTemplate

Checks whether a list of blocks matches a template by comparing the block names.

Parameters

  • blocks Array: Block list.
  • template Array: Block template.

Returns

  • boolean: Whether the list of blocks matches a templates.

findTransform

Given an array of transforms, returns the highest-priority transform where the predicate function returns a truthy value. A higher-priority transform is one with a lower priority value (i.e. first in priority order). Returns null if the transforms set is empty or the predicate function returns a falsey value for all entries.

Parameters

  • transforms Object[]: Transforms to search.
  • predicate Function: Function returning true on matching transform.

Returns

  • ?Object: Highest-priority transform candidate.

getBlockAttributes

Returns the block attributes of a registered block node given its type.

Parameters

  • blockTypeOrName string|Object: Block type or name.
  • innerHTML string|Node: Raw block content.
  • attributes ?Object: Known block attributes (from delimiters).

Returns

  • Object: All block attributes.

getBlockContent

Given a block object, returns the Block’s Inner HTML markup.

Parameters

  • block Object: Block instance.

Returns

  • string: HTML.

getBlockDefaultClassName

Returns the block’s default classname from its name.

Parameters

  • blockName string: The block name.

Returns

  • string: The block’s default class.

getBlockFromExample

Create a block object from the example API.

Parameters

  • name string:
  • example Object:

Returns

  • Object: block.

getBlockMenuDefaultClassName

Returns the block’s default menu item classname from its name.

Parameters

  • blockName string: The block name.

Returns

  • string: The block’s default menu item class.

getBlockSupport

Returns the block support value for a feature, if defined.

Parameters

  • nameOrType (string|Object): Block name or type object
  • feature string: Feature to retrieve
  • defaultSupports *: Default value to return if not explicitly defined

Returns

  • ?*: Block support value

getBlockTransforms

Returns normal block transforms for a given transform direction, optionally for a specific block by name, or an empty array if there are no transforms. If no block name is provided, returns transforms for all blocks. A normal transform object includes blockName as a property.

Parameters

  • direction string: Transform direction (“to”, “from”).
  • blockTypeOrName string|Object: Block type or name.

Returns

  • Array: Block transforms for direction.

getBlockType

Returns a registered block type.

Parameters

  • name string: Block name.

Returns

  • ?Object: Block type.

getBlockTypes

Returns all registered blocks.

Returns

  • Array: Block settings.

getChildBlockNames

Returns an array with the child blocks of a given block.

Parameters

  • blockName string: Name of block (example: “latest-posts”).

Returns

  • Array: Array of child block names.

getDefaultBlockName

Retrieves the default block name.

Returns

  • ?string: Block name.

getFreeformContentHandlerName

Retrieves name of block handling non-block content, or undefined if no handler has been defined.

Returns

  • ?string: Block name.

getGroupingBlockName

Retrieves name of block used for handling grouping interactions.

Returns

  • ?string: Block name.

getPhrasingContentSchema

Undocumented declaration.

getPossibleBlockTransformations

Returns an array of block types that the set of blocks received as argument can be transformed into.

Parameters

  • blocks Array: Blocks array.

Returns

  • Array: Block types that the blocks argument can be transformed to.

getSaveContent

Given a block type containing a save render implementation and attributes, returns the static markup to be saved.

Parameters

  • blockTypeOrName string|Object: Block type or name.
  • attributes Object: Block attributes.
  • innerBlocks ?Array: Nested blocks.

Returns

  • string: Save content.

getSaveElement

Given a block type containing a save render implementation and attributes, returns the enhanced element to be saved or string when raw HTML expected.

Parameters

  • blockTypeOrName string|Object: Block type or name.
  • attributes Object: Block attributes.
  • innerBlocks ?Array: Nested blocks.

Returns

  • Object|string: Save element or raw HTML string.

getUnregisteredTypeHandlerName

Retrieves name of block handling unregistered block types, or undefined if no handler has been defined.

Returns

  • ?string: Block name.

hasBlockSupport

Returns true if the block defines support for a feature, or false otherwise.

Parameters

  • nameOrType (string|Object): Block name or type object.
  • feature string: Feature to test.
  • defaultSupports boolean: Whether feature is supported by default if not explicitly defined.

Returns

  • boolean: Whether block supports feature.

hasChildBlocks

Returns a boolean indicating if a block has child blocks or not.

Parameters

  • blockName string: Name of block (example: “latest-posts”).

Returns

  • boolean: True if a block contains child blocks and false otherwise.

hasChildBlocksWithInserterSupport

Returns a boolean indicating if a block has at least one child block with inserter support.

Parameters

  • blockName string: Block type name.

Returns

  • boolean: True if a block contains at least one child blocks with inserter support and false otherwise.

isReusableBlock

Determines whether or not the given block is a reusable block. This is a special block type that is used to point to a global block stored via the API.

Parameters

  • blockOrType Object: Block or Block Type to test.

Returns

  • boolean: Whether the given block is a reusable block.

isTemplatePart

Determines whether or not the given block is a template part. This is a special block type that allows composing a page template out of reusable design elements.

Parameters

  • blockOrType Object: Block or Block Type to test.

Returns

  • boolean: Whether the given block is a template part.

isUnmodifiedBlock

Determines whether the block’s attributes are equal to the default attributes which means the block is unmodified.

Parameters

  • block WPBlock: Block Object

Returns

  • boolean: Whether the block is an unmodified block.

isUnmodifiedDefaultBlock

Determines whether the block is a default block and its attributes are equal to the default attributes which means the block is unmodified.

Parameters

  • block WPBlock: Block Object

Returns

  • boolean: Whether the block is an unmodified default block.

isValidBlockContent

Deprecated Use validateBlock instead to avoid data loss.

Returns true if the parsed block is valid given the input content. A block is considered valid if, when serialized with assumed attributes, the content matches the original value.

Logs to console in development environments when invalid.

Parameters

  • blockTypeOrName string|Object: Block type.
  • attributes Object: Parsed block attributes.
  • originalBlockContent string: Original block content.

Returns

  • boolean: Whether block is valid.

isValidIcon

Function that checks if the parameter is a valid icon.

Parameters

  • icon *: Parameter to be checked.

Returns

  • boolean: True if the parameter is a valid icon and false otherwise.

normalizeIconObject

Function that receives an icon as set by the blocks during the registration and returns a new icon object that is normalized so we can rely on just on possible icon structure in the codebase.

Parameters

  • icon WPBlockTypeIconRender: Render behavior of a block type icon; one of a Dashicon slug, an element, or a component.

Returns

  • WPBlockTypeIconDescriptor: Object describing the icon.

parse

Utilizes an optimized token-driven parser based on the Gutenberg grammar spec defined through a parsing expression grammar to take advantage of the regular cadence provided by block delimiters — composed syntactically through HTML comments — which, given a general HTML document as an input, returns a block list array representation.

This is a recursive-descent parser that scans linearly once through the input document. Instead of directly recursing it utilizes a trampoline mechanism to prevent stack overflow. This initial pass is mainly interested in separating and isolating the blocks serialized in the document and manifestly not in the content within the blocks.

Related

Parameters

  • content string: The post content.
  • options ParseOptions: Extra options for handling block parsing.

Returns

  • Array: Block list.

parseWithAttributeSchema

Given a block’s raw content and an attribute’s schema returns the attribute’s value depending on its source.

Parameters

  • innerHTML string|Node: Block’s raw content.
  • attributeSchema Object: Attribute’s schema.

Returns

  • *: Attribute value.

pasteHandler

Converts an HTML string to known blocks. Strips everything else.

Parameters

  • options Object:
  • options.HTML [string]: The HTML to convert.
  • options.plainText [string]: Plain text version.
  • options.mode [string]: Handle content as blocks or inline content. _ ‘AUTO’: Decide based on the content passed. _ ‘INLINE’: Always handle as inline content, and return string. * ‘BLOCKS’: Always handle as blocks, and return array of blocks.
  • options.tagName [Array]: The tag into which content will be inserted.

Returns

  • Array|string: A list of blocks or a string, depending on handlerMode.

rawHandler

Converts an HTML string to known blocks.

Parameters

  • $1 Object:
  • $1.HTML string: The HTML to convert.

Returns

  • Array: A list of blocks.

registerBlockCollection

Registers a new block collection to group blocks in the same namespace in the inserter.

Usage

import { __ } from '@wordpress/i18n';
import { registerBlockCollection, registerBlockType } from '@wordpress/blocks';

// Register the collection.
registerBlockCollection( 'my-collection', {
    title: __( 'Custom Collection' ),
} );

// Register a block in the same namespace to add it to the collection.
registerBlockType( 'my-collection/block-name', {
    title: __( 'My First Block' ),
    edit: () => <div>{ __( 'Hello from the editor!' ) }</div>,
    save: () => <div>'Hello from the saved content!</div>,
} );

Parameters

  • namespace string: The namespace to group blocks by in the inserter; corresponds to the block namespace.
  • settings Object: The block collection settings.
  • settings.title string: The title to display in the block inserter.
  • settings.icon [Object]: The icon to display in the block inserter.

registerBlockStyle

Registers a new block style for the given block.

For more information on connecting the styles with CSS the official documentation.

Usage

import { __ } from '@wordpress/i18n';
import { registerBlockStyle } from '@wordpress/blocks';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => {
                registerBlockStyle( 'core/quote', {
                    name: 'fancy-quote',
                    label: __( 'Fancy Quote' ),
                } );
            } }
        >
            { __( 'Add a new block style for core/quote' ) }
        </Button>
    );
};

Parameters

  • blockName string: Name of block (example: “core/latest-posts”).
  • styleVariation Object: Object containing name which is the class name applied to the block and label which identifies the variation to the user.

registerBlockType

Registers a new block provided a unique name and an object defining its behavior. Once registered, the block is made available as an option to any editor interface where blocks are implemented.

For more in-depth information on registering a custom block see the Create a block tutorial.

Usage

import { __ } from '@wordpress/i18n';
import { registerBlockType } from '@wordpress/blocks';

registerBlockType( 'namespace/block-name', {
    title: __( 'My First Block' ),
    edit: () => <div>{ __( 'Hello from the editor!' ) }</div>,
    save: () => <div>Hello from the saved content!</div>,
} );

Parameters

  • blockNameOrMetadata string|Object: Block type name or its metadata.
  • settings Object: Block settings.

Returns

  • WPBlockType | undefined: The block, if it has been successfully registered; otherwise undefined.

registerBlockVariation

Registers a new block variation for the given block type.

For more information on block variations see the official documentation .

Usage

import { __ } from '@wordpress/i18n';
import { registerBlockVariation } from '@wordpress/blocks';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => {
                registerBlockVariation( 'core/embed', {
                    name: 'custom',
                    title: __( 'My Custom Embed' ),
                    attributes: { providerNameSlug: 'custom' },
                } );
            } }
        >
            __( 'Add a custom variation for core/embed' ) }
        </Button>
    );
};

Parameters

  • blockName string: Name of the block (example: “core/columns”).
  • variation WPBlockVariation: Object describing a block variation.

serialize

Takes a block or set of blocks and returns the serialized post content.

Parameters

  • blocks Array: Block(s) to serialize.
  • options WPBlockSerializationOptions: Serialization options.

Returns

  • string: The post content.

serializeRawBlock

Serializes a block node into the native HTML-comment-powered block format. CAVEAT: This function is intended for re-serializing blocks as parsed by valid parsers and skips any validation steps. This is NOT a generic serialization function for in-memory blocks. For most purposes, see the following functions available in the @wordpress/blocks package:

Related

  • serializeBlock
  • serialize For more on the format of block nodes as returned by valid parsers:
  • @wordpress/block-serialization-default-parser package
  • @wordpress/block-serialization-spec-parser package

Parameters

  • rawBlock WPRawBlock: A block node as returned by a valid parser.
  • options [Options]: Serialization options.

Returns

  • string: An HTML string representing a block.

setCategories

Sets the block categories.

Usage

import { __ } from '@wordpress/i18n';
import { store as blocksStore, setCategories } from '@wordpress/blocks';
import { useSelect } from '@wordpress/data';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    // Retrieve the list of current categories.
    const blockCategories = useSelect(
        ( select ) => select( blocksStore ).getCategories(),
        []
    );

    return (
        <Button
            onClick={ () => {
                // Add a custom category to the existing list.
                setCategories( [
                    ...blockCategories,
                    { title: 'Custom Category', slug: 'custom-category' },
                ] );
            } }
        >
            { __( 'Add a new custom block category' ) }
        </Button>
    );
};

Parameters

  • categories WPBlockCategory[]: Block categories.

setDefaultBlockName

Assigns the default block name.

Usage

import { setDefaultBlockName } from '@wordpress/blocks';

const ExampleComponent = () => {
    return (
        <Button onClick={ () => setDefaultBlockName( 'core/heading' ) }>
            { __( 'Set the default block to Heading' ) }
        </Button>
    );
};

Parameters

  • name string: Block name.

setFreeformContentHandlerName

Assigns name of block for handling non-block content.

Parameters

  • blockName string: Block name.

setGroupingBlockName

Assigns name of block for handling block grouping interactions.

This function lets you select a different block to group other blocks in instead of the default core/group block. This function must be used in a component or when the DOM is fully loaded. See https://developer.wordpress.org/block-editor/reference-guides/packages/packages-dom-ready/

Usage

import { setGroupingBlockName } from '@wordpress/blocks';

const ExampleComponent = () => {
    return (
        <Button onClick={ () => setGroupingBlockName( 'core/columns' ) }>
            { __( 'Wrap in columns' ) }
        </Button>
    );
};

Parameters

  • name string: Block name.

setUnregisteredTypeHandlerName

Assigns name of block handling unregistered block types.

Parameters

  • blockName string: Block name.

store

Store definition for the blocks namespace.

Related

Type

  • Object

switchToBlockType

Switch one or more blocks into one or more blocks of the new block type.

Parameters

  • blocks Array|Object: Blocks array or block object.
  • name string: Block name.

Returns

  • ?Array: Array of blocks or null.

synchronizeBlocksWithTemplate

Synchronize a block list with a block template.

Synchronizing a block list with a block template means that we loop over the blocks keep the block as is if it matches the block at the same position in the template (If it has the same name) and if doesn’t match, we create a new block based on the template. Extra blocks not present in the template are removed.

Parameters

  • blocks Array: Block list.
  • template Array: Block template.

Returns

  • Array: Updated Block list.

unregisterBlockStyle

Unregisters a block style for the given block.

Usage

import { __ } from '@wordpress/i18n';
import { unregisterBlockStyle } from '@wordpress/blocks';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => {
                unregisterBlockStyle( 'core/quote', 'plain' );
            } }
        >
            { __( 'Remove the "Plain" block style for core/quote' ) }
        </Button>
    );
};

Parameters

  • blockName string: Name of block (example: “core/latest-posts”).
  • styleVariationName string: Name of class applied to the block.

unregisterBlockType

Unregisters a block.

Usage

import { __ } from '@wordpress/i18n';
import { unregisterBlockType } from '@wordpress/blocks';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => unregisterBlockType( 'my-collection/block-name' ) }
        >
            { __( 'Unregister my custom block.' ) }
        </Button>
    );
};

Parameters

  • name string: Block name.

Returns

  • WPBlockType | undefined: The previous block value, if it has been successfully unregistered; otherwise undefined.

unregisterBlockVariation

Unregisters a block variation defined for the given block type.

Usage

import { __ } from '@wordpress/i18n';
import { unregisterBlockVariation } from '@wordpress/blocks';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => {
                unregisterBlockVariation( 'core/embed', 'youtube' );
            } }
        >
            { __( 'Remove the YouTube variation from core/embed' ) }
        </Button>
    );
};

Parameters

  • blockName string: Name of the block (example: “core/columns”).
  • variationName string: Name of the variation defined for the block.

updateCategory

Updates a category.

Usage

import { __ } from '@wordpress/i18n';
import { updateCategory } from '@wordpress/blocks';
import { Button } from '@wordpress/components';

const ExampleComponent = () => {
    return (
        <Button
            onClick={ () => {
                updateCategory( 'text', { title: __( 'Written Word' ) } );
            } }
        >
            { __( 'Update Text category title' ) }
        </Button>
    );
};

Parameters

  • slug string: Block category slug.
  • category WPBlockCategory: Object containing the category properties that should be updated.

validateBlock

Returns an object with isValid property set to true if the parsed block is valid given the input content. A block is considered valid if, when serialized with assumed attributes, the content matches the original value. If block is invalid, this function returns all validations issues as well.

Parameters

  • block WPBlock: block object.
  • blockTypeOrName [WPBlockType|string]: Block type or name, inferred from block if not given.

Returns

  • [boolean,Array<LoggerItem>]: validation results.

withBlockContentContext

Deprecated

A Higher Order Component used to inject BlockContent using context to the wrapped component.

Parameters

  • OriginalComponent Component: The component to enhance.

Returns

  • Component: The same component.

Contributing to this package

This is an individual package that’s part of the Gutenberg project. The project is organized as a monorepo. It’s made up of multiple self-contained software packages, each with a specific purpose. The packages in this monorepo are published to npm and used by WordPress as well as other software projects.

To find out more about contributing to this package or Gutenberg as a whole, please read the project’s main contributor guide.