Move embed previews into core-data

core-blocks/embed/index.js

@@ -87,7 +87,7 @@ function getEmbedBlockSettings( { title, description, icon, category = 'embed',
 				const { url } = ownProps.attributes;
 				// Preview is undefined if we don't know the status of it, false if it failed,
 				// otherwise it will be an object containing the embed response.
-				const preview = url ? select( 'core/block-data' ).getPreview( url ) : undefined;
+				const preview = url ? select( 'core' ).getPreview( url ) : undefined;
 				return {
 					preview,
 				};

core-blocks/index.js

@@ -12,7 +12,6 @@ import deprecated from '@wordpress/deprecated';
  * Internal dependencies
  */
 import './style.scss';
-import './store';
 import * as paragraph from './paragraph';
 import * as image from './image';
 import * as heading from './heading';

core-data/actions.js

@@ -67,3 +67,20 @@ export function receiveThemeSupportsFromIndex( index ) {
 		themeSupports: index.theme_supports,
 	};
 }
+
+/**
+ * Returns an action object used in signalling that the preview data for
+ * a given URl has been received.
+ *
+ * @param {string}  url      URL to preview the embed for.
+ * @param {Mixed}   preview  Preview data.
+ *
+ * @return {Object} Action object.
+ */
+export function receivePreview( url, preview ) {
+	return {
+		type: 'RECEIVE_EMBED_PREVIEW',
+		url,
+		preview,
+	};
+}

core-data/reducer.js

@@ -135,6 +135,26 @@ function entity( entityConfig ) {
 	};
 }
 
+/**
+ * Reducer managing embed preview data.
+ *
+ * @param {Object} state  Current state.
+ * @param {Object} action Dispatched action.
+ *
+ * @return {Object} Updated state.
+ */
+export function embedPreviews( state = {}, action ) {
+	switch ( action.type ) {
+		case 'RECEIVE_EMBED_PREVIEW':
+			const { url, preview } = action;
+			return {
+				...state,
+				[ url ]: preview,
+			};
+	}
+	return state;
+}
+
 const entitiesByKind = groupBy( entitiesConfig, 'kind' );
 export const entities = combineReducers( Object.entries( entitiesByKind ).reduce( ( memo, [ kind, subEntities ] ) => {
 	const kindReducer = combineReducers( subEntities.reduce(
@@ -155,4 +175,5 @@ export default combineReducers( {
 	taxonomies,
 	themeSupports,
 	entities,
+	embedPreviews,
 } );

core-data/resolvers.js

@@ -3,6 +3,11 @@
  */
 import apiRequest from '@wordpress/api-request';
 
+/**
+ * External dependencies
+ */
+import { stringify } from 'querystring';
+
 /**
  * Internal dependencies
  */
@@ -11,6 +16,7 @@ import {
 	receiveUserQuery,
 	receiveEntityRecords,
 	receiveThemeSupportsFromIndex,
+	receivePreview,
 } from './actions';
 import { getEntity } from './entities';
 
@@ -65,3 +71,19 @@ export async function* getThemeSupports() {
 	const index = await apiRequest( { path: '/' } );
 	yield receiveThemeSupportsFromIndex( index );
 }
+
+/**
+ * Requests a preview from the from the Embed API.
+ *
+ * @param {Object} state State tree
+ * @param {string} url   URL to get the preview for.
+ */
+export async function* getPreview( state, url ) {
+	try {
+		const embedProxyResponse = await apiRequest( { path: `/oembed/1.0/proxy?${ stringify( { url } ) }` } );
+		yield receivePreview( url, embedProxyResponse );
+	} catch ( error ) {
+		// Embed API 404s if the URL cannot be embedded, so we have to catch the error from the apiRequest here.
+		yield receivePreview( url, false );
+	}
+}

core-data/selectors.js

@@ -145,3 +145,28 @@ export const getEntityRecords = createSelector(
 export function getThemeSupports( state ) {
 	return state.themeSupports;
 }
+
+/**
+ * Returns the embed preview for the given URL.
+ *
+ * @param {Object} state    Data state.
+ * @param {string} url      Embedded URL.
+ *
+ * @return {Mixed} Undefined if the preview has not been fetched, false if the URL cannot be embedded, array of embed preview data if the preview has been fetched.
+ */
+export function getPreview( state, url ) {
+	const preview = state.embedPreviews[ url ];
+
+	if ( ! preview ) {
+		return preview;
+	}
+
+	const oEmbedLinkCheck = '<a href="' + url + '">' + url + '</a>';
+
+	if ( oEmbedLinkCheck === preview.html ) {
+		// just a link to the url, it's oEmbed being helpful and creating a link for us, not actually embedding content
+		return false;
+	}
+
+	return preview;
+}