Add usePostThumbnail hook

src/hooks/usePostThumbnail/README.md

@@ -0,0 +1,49 @@
+# usePostThumbnail
+
+The `usePostThumbnail` hook allows for easy use and updates of the post thumbnail from within a
+
+## Usage
+
+The `usePostThumbnail` hook provides 2 values, and a setter function
+
+```js
+import { usePostThumbnail } from '@humanmade/block-editor-components';
+
+function BlockEdit() {
+	const { postThumbnail, postThumbnailId, setPostThumbnail } = usePostThumbnail();
+
+	return (
+		<>
+		<MediaUploadCheck>
+			<MediaUpload
+				onSelect={ ( media ) =>
+					setPostThumbnail( media.id )
+				}
+				allowedTypes={ ALLOWED_MEDIA_TYPES }
+				value={ postThumbnailId }
+				render={ ( { open } ) => (
+					<Button onClick={ open }>Open Media Library</Button>
+				) }
+			/>
+		</MediaUploadCheck>
+		<img alt={ postThumbnail?.alt_text } src={ postThumbnail?.source_url } />
+		<>
+	);
+}
+```
+
+## Return
+
+The `usePostThumbnail` hook returns an object with 3 properties:
+
+- `postThumbnail` - The full media object for the post thumbnail (as returned from `select( 'core' ).getMedia()`)
+- `postThumbnailId` - The ID of the thumbnail as an integer
+- `setPostThumbnail` - A function to set the current post's thumbnail by ID
+
+
+## Dependencies
+
+The `usePostThumbnail` hook requires the following dependencies, which are expected to be available:
+
+- `@wordpress/data`
+- `@wordpress/element`

src/hooks/usePostThumbnail/index.js

@@ -0,0 +1,50 @@
+import {
+	useDispatch,
+	useSelect,
+} from '@wordpress/data';
+import { useCallback } from '@wordpress/element';
+
+/**
+ * @typedef {object} postThumbnailUtils
+ * @property {?object} postThumbnail The post thumbnail object
+ * @property {?number} postThumbnailId The post thumbnail ID
+ * @property {Function} setPostThumbnail Function to set the post thumbnail
+ */
+
+/**
+ * Get the post thumbnail and a function to set it.
+ *
+ * @returns {postThumbnailUtils} The post thumbnail data and setter function
+ */
+export default function usePostThumbnail() {
+
+	const { editPost } = useDispatch( 'core/editor' );
+
+	const postThumbnailId = useSelect(
+		( select ) => select( 'core/editor' ).getEditedPostAttribute( 'featured_media' )
+	);
+
+	const postThumbnail = useSelect(
+		( select ) => {
+			if ( ! postThumbnailId ) {
+				return null;
+			}
+			return select( 'core' ).getMedia( postThumbnailId );
+		},
+		[ postThumbnailId ]
+	);
+
+	const setPostThumbnail = useCallback(
+		( mediaId ) => {
+		// If the image has been removed, we can remove the post thumbnail.
+			editPost( { featured_media: mediaId } );
+		},
+		[ editPost ]
+	);
+
+	return {
+		postThumbnail,
+		postThumbnailId,
+		setPostThumbnail,
+	};
+}

src/index.js

@@ -21,6 +21,7 @@ export { default as useActiveBlockStyle } from './hooks/useActiveBlockStyle';
 export { default as useBlockStyles } from './hooks/useBlockStyles';
 export { default as useDisallowedBlocks } from './hooks/useDisallowedBlocks';
 export { default as useMeta } from './hooks/useMeta';
+export { default as usePostThumbnail } from './hooks/usePostThumbnail';
 export { default as useRenderAppenderWithBlockLimit } from './hooks/useRenderAppenderWithBlockLimit';
 export { default as useSelectBlock } from './hooks/useSelectBlock';
 export { default as useSetAttribute } from './hooks/useSetAttribute';