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list of match types. * @property {Array<string>} operations A list of operations. * @property {number} reconnects The number of reconnects. */ /** * @alias query.Stream */ class Stream { /** * Creates a live updating object stream for a query * * @alias query.Stream.createStream<T> * @param {EntityManager} entityManager The owning entity manager of this query * @param {string} query The query options * @param {string} query.query The serialized query * @param {string} query.bucket The Bucket on which the streaming query is performed * @param {string=} query.sort the sort string * @param {number=} query.limit the count, i.e. the number of items in the result * @param {number=} query.offset offset, i.e. the number of items to skip * @param {boolean=} query.initial Indicates if the initial result should be returned * @param {Partial<StreamOptions>} options an object containing parameters * @return {Observable<RealtimeEvent<T>>} The query result as a live updating stream of objects */ static createEventStream(entityManager, query, options) { const opt = options || {}; opt.reconnects = 0; return Stream.streamObservable(entityManager, query, opt, (msg, next) => { const messageType = msg.type; delete msg.type; if (messageType === 'result') { msg.data.forEach((obj, index) => { const event = Object.assign({ matchType: 'add', operation: 'none', initial: true, }, msg); event.data = Stream.resolveObject(entityManager, obj); if (query.sort) { event.index = index; } next(event); }); } if (messageType === 'match') { msg.data = Stream.resolveObject(entityManager, msg.data); next(msg); } }); } /** * Creates a live updating result stream for a query * * @alias query.Stream.createStreamResult<T> * @param {EntityManager} entityManager The owning entity manager of this query * @param {string} query The query options * @param {string} query.query The serialized query * @param {string} query.bucket The Bucket on which the streaming query is performed * @param {string=} query.sort the sort string * @param {number=} query.limit the count, i.e. the number of items in the result * @param {number=} query.offset offset, i.e. the number of items to skip * @param {Partial<StreamOptions>} options an object containing parameters * @return {Observable<Array<T>>} The query result as a live updating query result */ static createResultStream(entityManager, query, options) { const opt = options || {}; opt.initial = true; opt.matchTypes = 'all'; opt.operations = 'any'; let result; const ordered = !!query.sort; return Stream.streamObservable(entityManager, query, opt, (event, next) => { if (event.type === 'result') { result = event.data.map(obj => Stream.resolveObject(entityManager, obj)); next(result.slice()); } if (event.type === 'match') { const obj = Stream.resolveObject(entityManager, event.data); if (event.matchType === 'remove' || event.matchType === 'changeIndex') { // if we have removed the instance our self, we do not have the cached instances anymore // therefore we can't find it anymore in the result by identity for (let i = 0, len = result.length; i < len; i += 1) { if (result[i].id === event.data.id) { result.splice(i, 1); break; } } } if (event.matchType === 'add' || event.matchType === 'changeIndex') { if (ordered) { result.splice(event.index, 0, obj); } else { result.push(obj); } } next(result.slice()); } }); } static streamObservable(entityManager, query, options, mapper) { const opt = Stream.parseOptions(options); const socket = entityManager.entityManagerFactory.websocket; const observable = new lib.Observable((subscriber) => { const id = uuid(); const stream = socket.openStream(entityManager.tokenStorage, id); stream.send(Object.assign({ type: 'subscribe', }, query, opt)); let closed = false; const next = subscriber.next.bind(subscriber); const subscription = stream.subscribe({ complete() { closed = true; subscriber.complete(); }, error(e) { closed = true; subscriber.error(e); }, next(msg) { mapper(msg, next); }, }); return () => { if (!closed) { // send unsubscribe only when we aren't completed by the socket and call it only once stream.send({ type: 'unsubscribe' }); subscription.unsubscribe(); closed = true; } }; }); return Stream.cachedObservable(observable, opt); } static cachedObservable(observable, options) { let subscription = null; const observers = []; return new lib.Observable((observer) => { if (!subscription) { let remainingRetries = options.reconnects; let backoff = 1; const subscriptionObserver = { next(msg) { // reset the backoff if we get a message backoff = 1; observers.forEach(o => o.next(msg)); }, error(e) { observers.forEach(o => o.error(e)); }, complete() { if (remainingRetries !== 0) { remainingRetries = remainingRetries < 0 ? -1 : remainingRetries - 1; setTimeout(() => { subscription = observable.subscribe(subscriptionObserver); }, backoff * 1000); backoff *= 2; } else { observers.forEach(o => o.complete()); } }, }; subscription = observable.subscribe(subscriptionObserver); } observers.push(observer); return () => { observers.splice(observers.indexOf(observer), 1); if (!observers.length) { subscription.unsubscribe(); subscription = null; } }; }); } /** * Parses the StreamOptions * * @param {Partial<StreamOptions>=} [options] object containing partial options * @returns {StreamOptions} an object containing VALID options */ static parseOptions(options) { const opt = options || {}; const verified = { initial: opt.initial === undefined || !!opt.initial, matchTypes: Stream.normalizeMatchTypes(opt.matchTypes), operations: Stream.normalizeOperations(opt.operations), reconnects: Stream.normalizeReconnects(opt.reconnects), }; if (verified.matchTypes.indexOf('all') === -1 && verified.operations.indexOf('any') === -1) { throw new Error('Only subscriptions for either operations or matchTypes are allowed. You cannot subscribe to a query using matchTypes and operations at the same time!'); } return verified; } static normalizeMatchTypes(list) { return Stream.normalizeSortedSet(list, 'all', 'match types', ['add', 'change', 'changeIndex', 'match', 'remove']); } static normalizeReconnects(reconnects) { if (reconnects === undefined) { return -1; } return reconnects < 0 ? -1 : Number(reconnects); } static normalizeOperations(list) { return Stream.normalizeSortedSet(list, 'any', 'operations', ['delete', 'insert', 'none', 'update']); } static normalizeSortedSet(list, wildcard, itemType, allowedItems) { if (!list) { return [wildcard]; } const li = Array.isArray(list) ? list : [list]; if (li.length === 0) { // undefined or empty list --> default value return [wildcard]; } // sort, remove duplicates and check whether all values are allowed li.sort(); let item; let lastItem; for (let i = li.length - 1; i >= 0; i -= 1) { item = li[i]; if (!item) { // undefined and null item in the list --> invalid! throw new Error('undefined and null not allowed!'); } if (item === lastItem) { // remove duplicates li.splice(i, 1); } if (item === wildcard) { return [wildcard]; } if (allowedItems.indexOf(item) === -1) { // raise error on invalid elements throw new Error(item + ' not allowed for ' + itemType + '! (permitted: ' + allowedItems + '.)'); } lastItem = item; } return li; } static resolveObject(entityManager, object) { const entity = entityManager.getReference(object.id); const metadata = Metadata.get(entity); if (!object.version) { metadata.setRemoved(); entityManager.removeReference(entity); } else if (entity.version <= object.version) { metadata.setJson(object, { persisting: true }); } return entity; } } module.exports = Stream; </code></pre> </article> </section>  </div> </div> </div> </div> </div> <div id="footer" style="position:relative; z-index:1;"> <div class="container"> <div class="row"> <div class="col-xs-6 col-sm-3 sitemap"> <h4>Product</h4> <a href="https://www.baqend.com/platform.html">Platform</a> <a href="https://www.baqend.com/speedkit.html">Speed Kit</a> <a href="https://www.baqend.com/features.html">Features</a> <a href="https://www.baqend.com/pricing.html">Platform Pricing</a> <a href="https://www.baqend.com/pricing_speedkit.html">Speed Kit Pricing</a> <a href="https://www.baqend.com/agencies.html">Agencies</a> <a href="https://www.baqend.com/enterprise.html">Enterprise</a> <a href="https://www.baqend.com/features.html#download">Community Edition</a> <a href="https://www.baqend.com/support.html">Support</a> </div> <div class="col-xs-6 col-sm-3 sitemap"> <h4>Company</h4> <a href="https://www.baqend.com/about.html">About us</a> <a href="https://medium.baqend.com">Baqend Blog</a> <a href="https://www.baqend.com/hiring.html">Jobs</a> <a href="https://www.baqend.com/press.html">Press</a> <a href="https://thesis.app.baqend.com/">Bachelor/Master theses</a> <a href="https://www.weblabs.hamburg/">WebLabs.Hamburg</a> </div> <div class="col-xs-6 col-sm-3 sitemap"> <h4>Developer</h4> <a href="https://dashboard.baqend.com/login">Login</a> <a href="https://dashboard.baqend.com/register">Sign Up</a> <a href="https://www.baqend.com/guide">Developer Docs</a> <a href="https://www.baqend.com/guide/roadmap/">Roadmap</a> <a href="https://www.baqend.com/guide/starter-kits">Starter Kits</a> <a href="https://www.baqend.com/js-sdk/latest/baqend.html">JS SDK</a> <a href="https://stackoverflow.com/questions/tagged/baqend/">Stackoverflow</a> </div> <div class="col-xs-6 col-sm-3 contact"> <h4>Contact</h4> <p class="contact-information"> <span> Baqend GmbH<br /> Stresemannstr. 23<br /> 22769 Hamburg<br /> Germany </span> </p> <p class="contact-information"> Email: <a style="display: inline-block" href="mailto:support@baqend.com">support@baqend.com</a> </p> <p class="contact-information"> Tel: <a style="display: inline-block" href="tel:+494060940539">+49 40 60940539</a> </p> </div> </div> <div class="row"> <div class="col-md-12 text-center social"> <a href="https://twitter.com/baqendcom"><i class="fa fa-twitter fa-fw"></i></a> <a href="https://github.com/Baqend"><i class="fa fa-github fa-fw"></i></a> <a href="https://medium.baqend.com/"><i class="fa fa-medium fa-fw"></i></a> <a href="https://www.facebook.com/baqend"><i class="fa fa-facebook fa-fw"></i></a> <a href="https://www.youtube.com/channel/UCsImg6Ts8UEp6-7LE9CP2-Q"><i class="fa fa-youtube fa-fw"></i></a> </div> </div> </div> <footer> <div class="container"> <div class="legal text-center"> <div> <strong>Baqend JavaScript SDK 2.14.1</strong><br> &copy 2019 Baqend GmbH<br> Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Sun, 06 Jan 2019 05:00:21 GMT </div> <a href="mailto:info@baqend.com">Contact</a> - <a href="https://dashboard.baqend.com/privacy">Privacy Policy</a> - <a href="https://dashboard.baqend.com/terms">Terms of Service</a> - <a href="https://dashboard.baqend.com/imprint">Imprint</a> </div> </div> </footer> </div> <script> prettyPrint(); </script> <script src="https://code.jquery.com/jquery-1.12.1.min.js"></script> <script src="scripts/bootstrap.min.js"> </script> <script src="scripts/linenumber.js"> </script> <script src="scripts/filter.js"> </script> <script data-main="scripts/search.js" src="scripts/require.js"></script> </body> </html>