/* Copyright 2018 New Vector Ltd Licensed under the Apache License, Version 2.0 (the 'License'); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ import URL from 'url'; import dis from './dispatcher'; import IntegrationManager from './IntegrationManager'; import WidgetMessagingEndpoint from './WidgetMessagingEndpoint'; const WIDGET_API_VERSION = '0.0.1'; // Current API version const SUPPORTED_WIDGET_API_VERSIONS = [ '0.0.1', ]; const INBOUND_API_NAME = 'fromWidget'; // Listen for and handle incomming requests using the 'fromWidget' postMessage // API and initiate responses export default class FromWidgetPostMessageApi { constructor() { this.widgetMessagingEndpoints = []; this.start = this.start.bind(this); this.stop = this.stop.bind(this); this.onPostMessage = this.onPostMessage.bind(this); } start() { window.addEventListener('message', this.onPostMessage); } stop() { window.removeEventListener('message', this.onPostMessage); } /** * Register a widget endpoint for trusted postMessage communication * @param {string} widgetId Unique widget identifier * @param {string} endpointUrl Widget wurl origin (protocol + (optional port) + host) */ addEndpoint(widgetId, endpointUrl) { const u = URL.parse(endpointUrl); if (!u || !u.protocol || !u.host) { console.warn('Add FromWidgetPostMessageApi endpoint - Invalid origin:', endpointUrl); return; } const origin = u.protocol + '//' + u.host; const endpoint = new WidgetMessagingEndpoint(widgetId, origin); if (this.widgetMessagingEndpoints.some(function(ep) { return (ep.widgetId === widgetId && ep.endpointUrl === endpointUrl); })) { // Message endpoint already registered console.warn('Add FromWidgetPostMessageApi - Endpoint already registered'); return; } else { console.warn(`Adding fromWidget messaging endpoint for ${widgetId}`, endpoint); this.widgetMessagingEndpoints.push(endpoint); } } /** * De-register a widget endpoint from trusted communication sources * @param {string} widgetId Unique widget identifier * @param {string} endpointUrl Widget wurl origin (protocol + (optional port) + host) * @return {boolean} True if endpoint was successfully removed */ removeEndpoint(widgetId, endpointUrl) { const u = URL.parse(endpointUrl); if (!u || !u.protocol || !u.host) { console.warn('Remove widget messaging endpoint - Invalid origin'); return; } const origin = u.protocol + '//' + u.host; if (this.widgetMessagingEndpoints && this.widgetMessagingEndpoints.length > 0) { const length = this.widgetMessagingEndpoints.length; this.widgetMessagingEndpoints = this.widgetMessagingEndpoints. filter(function(endpoint) { return (endpoint.widgetId != widgetId || endpoint.endpointUrl != origin); }); return (length > this.widgetMessagingEndpoints.length); } return false; } /** * Handle widget postMessage events * Messages are only handled where a valid, registered messaging endpoints * @param {Event} event Event to handle * @return {undefined} */ onPostMessage(event) { if (!event.origin) { // Handle chrome event.origin = event.originalEvent.origin; } // Event origin is empty string if undefined if ( event.origin.length === 0 || !this.trustedEndpoint(event.origin) || event.data.api !== INBOUND_API_NAME || !event.data.widgetId ) { return; // don't log this - debugging APIs like to spam postMessage which floods the log otherwise } // Although the requestId is required, we don't use it. We'll be nice and process the message // if the property is missing, but with a warning for widget developers. if (!event.data.requestId) { console.warn("fromWidget action '" + event.data.action + "' does not have a requestId"); } const action = event.data.action; const widgetId = event.data.widgetId; if (action === 'content_loaded') { console.warn('Widget reported content loaded for', widgetId); dis.dispatch({ action: 'widget_content_loaded', widgetId: widgetId, }); this.sendResponse(event, {success: true}); } else if (action === 'supported_api_versions') { this.sendResponse(event, { api: INBOUND_API_NAME, supported_versions: SUPPORTED_WIDGET_API_VERSIONS, }); } else if (action === 'api_version') { this.sendResponse(event, { api: INBOUND_API_NAME, version: WIDGET_API_VERSION, }); } else if (action === 'm.sticker') { // console.warn('Got sticker message from widget', widgetId); // NOTE -- The widgetData field is deprecated (in favour of the 'data' field) and will be removed eventually const data = event.data.data || event.data.widgetData; dis.dispatch({action: 'm.sticker', data: data, widgetId: event.data.widgetId}); } else if (action === 'integration_manager_open') { // Close the stickerpicker dis.dispatch({action: 'stickerpicker_close'}); // Open the integration manager // NOTE -- The widgetData field is deprecated (in favour of the 'data' field) and will be removed eventually const data = event.data.data || event.data.widgetData; const integType = (data && data.integType) ? data.integType : null; const integId = (data && data.integId) ? data.integId : null; IntegrationManager.open(integType, integId); } else { console.warn('Widget postMessage event unhandled'); this.sendError(event, {message: 'The postMessage was unhandled'}); } } /** * Check if message origin is registered as trusted * @param {string} origin PostMessage origin to check * @return {boolean} True if trusted */ trustedEndpoint(origin) { if (!origin) { return false; } return this.widgetMessagingEndpoints.some((endpoint) => { // TODO / FIXME -- Should this also check the widgetId? return endpoint.endpointUrl === origin; }); } /** * Send a postmessage response to a postMessage request * @param {Event} event The original postMessage request event * @param {Object} res Response data */ sendResponse(event, res) { const data = JSON.parse(JSON.stringify(event.data)); data.response = res; event.source.postMessage(data, event.origin); } /** * Send an error response to a postMessage request * @param {Event} event The original postMessage request event * @param {string} msg Error message * @param {Error} nestedError Nested error event (optional) */ sendError(event, msg, nestedError) { console.error('Action:' + event.data.action + ' failed with message: ' + msg); const data = JSON.parse(JSON.stringify(event.data)); data.response = { error: { message: msg, }, }; if (nestedError) { data.response.error._error = nestedError; } event.source.postMessage(data, event.origin); } }