Move embed API call out of block and into data

core-blocks/embed/test/index.js

@@ -1,12 +1,17 @@
+/**
+ * External dependencies
+ */
+import { render } from 'enzyme';
+
 /**
  * Internal dependencies
  */
-import { name, settings } from '../';
-import { blockEditRender } from '../../test/helpers';
+import { getEmbedEdit } from '../';
 
 describe( 'core/embed', () => {
 	test( 'block edit matches snapshot', () => {
-		const wrapper = blockEditRender( name, settings );
+		const EmbedEdit = getEmbedEdit( 'Embed', 'embed-generic' );
+		const wrapper = render( <EmbedEdit attributes={ {} } /> );
 
 		expect( wrapper ).toMatchSnapshot();
 	} );

packages/core-data/src/actions.js

@@ -81,3 +81,20 @@ 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 receiveEmbedPreview( url, preview ) {
+	return {
+		type: 'RECEIVE_EMBED_PREVIEW',
+		url,
+		preview,
+	};
+}

packages/core-data/src/reducer.js

@@ -201,10 +201,31 @@ export const entities = ( state = {}, action ) => {
 	};
 };
 
+/**
+ * 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;
+}
+
 export default combineReducers( {
 	terms,
 	users,
 	taxonomies,
 	themeSupports,
 	entities,
+	embedPreviews,
 } );

packages/core-data/src/resolvers.js

@@ -8,6 +8,11 @@ import { find } from 'lodash';
  */
 import apiFetch from '@wordpress/api-fetch';
 
+/**
+ * External dependencies
+ */
+import { stringify } from 'querystring';
+
 /**
  * Internal dependencies
  */
@@ -16,6 +21,7 @@ import {
 	receiveUserQuery,
 	receiveEntityRecords,
 	receiveThemeSupportsFromIndex,
+	receiveEmbedPreview,
 } from './actions';
 import { getKindEntities } from './entities';
 
@@ -78,3 +84,19 @@ export async function* getThemeSupports() {
 	const index = await apiFetch( { 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* getEmbedPreview( state, url ) {
+	try {
+		const embedProxyResponse = await apiFetch( { path: `/oembed/1.0/proxy?${ stringify( { url } ) }` } );
+		yield receiveEmbedPreview( 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 receiveEmbedPreview( url, false );
+	}
+}

packages/core-data/src/selectors.js

@@ -168,3 +168,36 @@ 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 {*} Undefined if the preview has not been fetched, otherwise, the preview fetched from the embed preview API.
+ */
+export function getEmbedPreview( state, url ) {
+	return state.embedPreviews[ url ];
+}
+
+/**
+ * Determines if the returned preview is an oEmbed link fallback.
+ *
+ * WordPress can be configured to return a simple link to a URL if it is not embeddable.
+ * We need to be able to determine if a URL is embeddable or not, based on what we
+ * get back from the oEmbed preview API.
+ *
+ * @param {Object} state    Data state.
+ * @param {string} url      Embedded URL.
+ *
+ * @return {booleans} Is the preview for the URL an oEmbed link fallback.
+ */
+export function isPreviewEmbedFallback( state, url ) {
+	const preview = state.embedPreviews[ url ];
+	const oEmbedLinkCheck = '<a href="' + url + '">' + url + '</a>';
+	if ( ! preview ) {
+		return false;
+	}
+	return preview.html === oEmbedLinkCheck;
+}

packages/core-data/src/test/reducer.js

@@ -7,7 +7,7 @@ import { filter } from 'lodash';
 /**
  * Internal dependencies
  */
-import { terms, entities } from '../reducer';
+import { terms, entities, embedPreviews } from '../reducer';
 
 describe( 'terms()', () => {
 	it( 'returns an empty object by default', () => {
@@ -93,3 +93,24 @@ describe( 'entities', () => {
 		] );
 	} );
 } );
+
+describe( 'embedPreviews()', () => {
+	it( 'returns an empty object by default', () => {
+		const state = embedPreviews( undefined, {} );
+
+		expect( state ).toEqual( {} );
+	} );
+
+	it( 'returns with received preview', () => {
+		const originalState = deepFreeze( {} );
+		const state = embedPreviews( originalState, {
+			type: 'RECEIVE_EMBED_PREVIEW',
+			url: 'http://twitter.com/notnownikki',
+			preview: { data: 42 },
+		} );
+
+		expect( state ).toEqual( {
+			'http://twitter.com/notnownikki': { data: 42 },
+		} );
+	} );
+} );

packages/core-data/src/test/resolvers.js

@@ -3,11 +3,16 @@
  */
 import apiFetch from '@wordpress/api-fetch';
 
+/**
+ * External dependencies
+ */
+import { stringify } from 'querystring';
+
 /**
  * Internal dependencies
  */
-import { getCategories, getEntityRecord, getEntityRecords } from '../resolvers';
-import { receiveTerms, receiveEntityRecords, addEntities } from '../actions';
+import { getCategories, getEntityRecord, getEntityRecords, getEmbedPreview } from '../resolvers';
+import { receiveTerms, receiveEntityRecords, addEntities, receiveEmbedPreview } from '../actions';
 
 jest.mock( '@wordpress/api-fetch', () => jest.fn() );
 
@@ -105,3 +110,31 @@ describe( 'getEntityRecords', () => {
 		expect( received ).toEqual( receiveEntityRecords( 'root', 'postType', Object.values( POST_TYPES ) ) );
 	} );
 } );
+
+describe( 'getEmbedPreview', () => {
+	const SUCCESSFUL_EMBED_RESPONSE = { data: '<p>some html</p>' };
+	const UNEMBEDDABLE_RESPONSE = false;
+	const EMBEDDABLE_URL = 'http://twitter.com/notnownikki';
+	const UNEMBEDDABLE_URL = 'http://example.com/';
+
+	beforeAll( () => {
+		apiFetch.mockImplementation( ( options ) => {
+			if ( options.path === `/oembed/1.0/proxy?${ stringify( { url: EMBEDDABLE_URL } ) }` ) {
+				return Promise.resolve( SUCCESSFUL_EMBED_RESPONSE );
+			}
+			throw 404;
+		} );
+	} );
+
+	it( 'yields with fetched embed preview', async () => {
+		const fulfillment = getEmbedPreview( {}, EMBEDDABLE_URL );
+		const received = ( await fulfillment.next() ).value;
+		expect( received ).toEqual( receiveEmbedPreview( EMBEDDABLE_URL, SUCCESSFUL_EMBED_RESPONSE ) );
+	} );
+
+	it( 'yields false if the URL cannot be embedded', async () => {
+		const fulfillment = getEmbedPreview( {}, UNEMBEDDABLE_URL );
+		const received = ( await fulfillment.next() ).value;
+		expect( received ).toEqual( receiveEmbedPreview( UNEMBEDDABLE_URL, UNEMBEDDABLE_RESPONSE ) );
+	} );
+} );

packages/core-data/src/test/selectors.js

@@ -6,7 +6,14 @@ import deepFreeze from 'deep-freeze';
 /**
  * Internal dependencies
  */
-import { getTerms, isRequestingCategories, getEntityRecord, getEntityRecords } from '../selectors';
+import {
+	getTerms,
+	isRequestingCategories,
+	getEntityRecord,
+	getEntityRecords,
+	getEmbedPreview,
+	isPreviewEmbedFallback,
+} from '../selectors';
 import { select } from '@wordpress/data';
 
 jest.mock( '@wordpress/data', () => {
@@ -138,3 +145,29 @@ describe( 'getEntityRecords', () => {
 	} );
 } );
 
+describe( 'getEmbedPreview()', () => {
+	it( 'returns preview stored for url', () => {
+		let state = deepFreeze( {
+			embedPreviews: {},
+		} );
+		expect( getEmbedPreview( state, 'http://example.com/' ) ).toBe( undefined );
+
+		state = deepFreeze( {
+			embedPreviews: {
+				'http://example.com/': { data: 42 },
+			},
+		} );
+		expect( getEmbedPreview( state, 'http://example.com/' ) ).toEqual( { data: 42 } );
+	} );
+} );
+
+describe( 'isPreviewEmbedFallback()', () => {
+	it( 'returns true if the preview html is just a single link', () => {
+		const state = deepFreeze( {
+			embedPreviews: {
+				'http://example.com/': { html: '<a href="http://example.com/">http://example.com/</a>' },
+			},
+		} );
+		expect( isPreviewEmbedFallback( state, 'http://example.com/' ) ).toEqual( true );
+	} );
+} );