Firestore Query Snapshot















In our forthcoming posts we’ll see how to write queries to query for data in an efficient way. This App is nothing I want to publish, I just want to practice the Firebase Firestore coding etc. NOTE : “500/50/5” rule. Since the Firebase team launched Cloud Firestore last week, one question/problem that keeps popping up on Stackoverflow is the result of there being two different ways to retrieve data that have to…. You can read the individual changelogs for details (Android, iOS, web), but we wanted to expand on three highly requested features shipping with this release: atomic multi-location writes, ordering queries by deep paths, and iOS 9 bitcode support. Cloud Firestore queries are shallow, so when you make a query to a document, it will not have a sub-collection on it. Either of these methods can be used with documents, collections of documents, or the results of queries: Call a method to get the data. Firestore stores your data in objects called documents, which are grouped into collections. Now we even have to disable the persistence, and even then its still slow. query property in the order they will be chained with the query method as the only property and it's value being an array of arguments, or a single string value as show below. They have their own query methods that are way more developer-friendly than the realtimeDB. Here we will add all the necessary methods, in order to write, update, read, listen, filter, make a transaction and delete to/from Google Cloud Firestore. These queries can also be used with either get() or addSnapshotListener(), as described in Get Data and Get Realtime Updates. Firebase Cloud Firestore. WhereEqualTo("StatusLido", "N") Dim QuerySnapshot As QuerySnapshot = Await Query. You can also construct refined Query objects by adding filters and ordering. These queries can also be used with either get() or addSnapshotListener(), as described above. I'm making a simple node based forum (although I'm pretty new to Node so it's not that good lol) and I'm trying to query post data from the server to send back to the client. AngularFire2 provides this data in the snapshotChanges() method, making it possible to map custom objects that have the raw snapshot we need as a cursor. collection(documentName). In Firstore, you need to make a brand new query with a document cursor each time you want more data. vue-computed-firestore. The only feedback I have is that the cloud engine adds a "read". onSnapshot() and firebase. That’s right, the initial ‘Sample Album’ has gone and we see an empty screen. Working with Firebase Documents in ClojureScript. API docs for the QuerySnapshot class from the cloud_firestore library, for the Dart programming language. It can contain zero or more DocumentSnapshot objects. Currently that's impossible, because Firestore. com 前回までで「Raspberry Pi のCPU温度をfirebaseの Cloud Firestore に記録してVue. type Test_Query struct { Query *QueryTest `protobuf:"bytes,8,opt,name=query,proto3,oneof"` } type Test_Set ¶ Uses type Test_Set struct { Set * SetTest `protobuf:"bytes,4,opt,name=set,proto3,oneof"` }. get document based on the query and if there is no error get the documentID for the first document in snapshot documents. This will be a simple demo. It is the successor to Firebase's original databasing system, Real-time Database, and allows for nested documents and fields rather than the tree-view provided in the Real-time Database. Collections are just containers of documents. In this function we will do the following: 1. At this point our query does work, but as we have not added any albums yet, it correctly shows the empty screen. The values in the document snapshot serve as the values in the query cursor. Firestore supports multiple types of data for fields. lastFetchedUser는 현재 Firebase에 등록된 개수만큼 실행된다. For example, take a snapshot of a "San Francisco" document in your data set of cities and populations. Timestamp object? or can i query/insert the normal JS Date object and it will get converted automatically? Thanks. This will be a simple demo. Documents Dim doc As String = documentSnapshot. In real life, your databases will be more complex and you might use a different kind of a database. FirestoreはRealtime Databaseと同様のデータベースサービス。Realtime DatabaseがJSONで構造化されたデータをストアするのに. Cloud Firestore provides powerful query functionality for specifying which documents you want to retrieve from a collection or collection group. Querying This is the best part of Firestore. Important: As explained above under Events for. 4 (also reproduce in 0. This page provides Java source code for FirestoreRecyclerOptions. OK, I Understand. A horizontally scalable, globally consistent, relational database service. The usual practice is to query the database directly from the client, but sometimes it's better to route through Cloud Functions. It is not stable, and may be subject to changes. A document is essentially a map, from field names to field values. API docs for the QuerySnapshot class from the cloud_firestore library, for the Dart programming language. We have created a sample employee record management system and perform CRUD operations on it. Overview; auth:import and auth:export; Firebase Realtime Database Operation Types. // FIXME: if a client modifies _version along with other fields, we won’t create a versioned snapshot. In addition, it is useful to map the document snapshots to their raw data payload at this point to keep the main widget build method free of business logic. Los programadores móviles se han aprovechado de la base Firebase Realtime Database de Google como un servicio móvil (MBaaS) durante muchos años, ayudándoles a concentrarse en crear funciones para sus aplicaciones sin tener que preocuparse por la infraestructura de back-end y la base de datos. Go back to the file scripts/FriendlyEats. Firestore instance gets snapshots. query, data: data})}) Sign up for free to join this conversation on. Subclassing is not supported in production code and new SDK releases may break code that does so. Cloud Firestore caches data that your app is actively using, so the app can write, read, listen to, and query data even if the device is offline. 이미 order로 정렬되어서 가져와진 데이터이기 때문에 마지막에 fetch된 user만 저장해 놓은 후에 그 뒤(start(from: ~))부터 가져온 snapshot에서 데이터가 오기 때문에 겹치지 않는다. If you notice, I am creating a stream with data from the markers collection in firestore. NET type that a value will be deserialized as, when no other information is available. Then for every feedID, get documents for the feed details and return back to list of them. The usual practice is to query the database directly from the client, but sometimes it's better to route through Cloud Functions. Cloud Firestore provides powerful query functionality for specifying which documents you want to retrieve from a collection. The values in the document snapshot serve as the values in the query cursor. QuerySnapshot. // FIXME: if a client modifies _version along with other fields, we won’t create a versioned snapshot. The snapshot handler will receive a new query snapshot every time the query results change (that is, when a document is added, removed, or modified). Cloud Firestore caches data that your app is actively using, so the app can write, read, listen to, and query data even if the device is offline. We'll talk more about rules later in this codelab but first we need to set some basic rules on our data to get started. Let’s start with the Age filter. Cloud Firestore を使う利点の一つにリアルタイムに変更を取得できる点が挙げられます。公式ドキュメントでは Go SDK はまだサポートされていないと書かれていますが(2018/12/5 時点)、機能自体は SDK に実装されています (v0. Subclassing Note: Cloud Firestore classes are not meant to be subclassed except for use in test mocks. Firestore is a NoSQL database, which allows us to store data in form of collections and documents. In real life, your databases will be more complex and you might use a different kind of a database. Once that's been completed, you will be able to write simple queries on Firestore. That’s it guys. First, let's construct the query that will serve the default, unfiltered list of restaurants. First all feed ID from User/FeedIDs collection. 这虽然完全适用于Firebase RealTime数据库,但. I find the behavior of the serverTimestamp tag counter-intuitive and surprising. In addition to returning the snapshot value, the hooks provide an. The documents can be accessed as an array via the `docs` property or enumerated using the `forEach` method. onSnapshot((snapshot) =>. Firestore instance gets snapshots. Working with Firebase Documents in ClojureScript. In our forthcoming posts we’ll see how to write queries to query for data in an efficient way. firestore(). Description Cloud Firestore is an auto-scaling document database for storing, syncing, and querying data for mobile and web apps. Query cursors define the start and end points for a query, allowing you to: Return a subset of the data. This resource manages composite indexes and not single field indexes. firestore & storage 사용하기 firestore 에는 문서를 저장하고, storage 에는 파일을 저장합니다. In this function we will do the following: 1. collection(documentName). Important: As explained above under Events for local changes, you will receive events immediately for your local writes. Within these collections, you can have more collections called subcollections up to 100 levels deep. Custom Filterable FirebaseRecyclerAdapter. js Firestore example – Vue. iBeaconを検知して、そのデータをFirestoreに保存します。 おそらくiBeacon監視のデファクトなAltBeaconでやります。 つづいて保存部分です。 AndroidStudioのFirebaseのアシスタント機能を使ってやり. To begin querying data in Firestore you must first fill in the Project Id property on the Resource screen. In addition to returning the snapshot value, the hooks provide an. The snapshot handler will receive a new query snapshot every time the query results change (that is, when a document is added, removed, or modified). A Flutter plugin to use the Cloud Firestore API. In our case, we want to combine both Observable streams of query California and Colorado into 1 single stream: Creating Observables from Firestore snapshots Creating observables from Firestore. Call Next on the iterator to get a snapshot of the query's results each. 『今回はCloud Firestoreを使ってみましょう 「コレクション」「ドキュメント」「フィールド」 PHPいらなくね?って改めて思ってしまう』自作の小説や楽曲がうっかりちゃっかりひっそり存在しているところです。. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. Paginate query results. What is the actual difference between QueryReference and Snapshot?. The documents can be accessed as an array via the `docs` property or enumerated using the `forEach` method. I've tested it and it works but there could be a possibility of checking for the same value twice which means the second time it will accept the user since I'm just assuming it's going to. Sign in - Google Accounts - Firebase. * vuefire v2. Subclassing is not supported in production code and new SDK releases may break code that does so. Cloud Firestore는 사용자(users), 전체 포스트(posts)의 2가지 스키마로 구성하여 변환하였다. It supports offline mode so our app will work fine (write, read, listen to, and query data) whether device has internet connection or not, it automatically fetches changes from our database to Firebase Server. I am guessing I can modify these scripts for that purpose but have no idea what to do with clearly: 1> Where is the export_db. The fact that I can get a snapshot back from the server saying document A exists, yet fail a firebase rule for document B that says exists(A), isn't something that I expect to see. Firebaseの新しいデータベース 1. First, let's construct the query that will serve the default, unfiltered list of restaurants. This option is only available after installing firestorePlugin. To me, both seem to like returns the data from the store. It can contain zero or more DocumentSnapshot objects. How is it different from angularfire2 or angularfire-lite? Those libraries are much bigger and wrap all or most API's from Firebase SDK. Firestore instance gets snapshots. should the user documents have the same id as in Firestore? Query by multiple. Then for every feedID, get documents for the feed details and return back to list of them. Sign in - Google Accounts - Firebase. An initial call using the callback you provide creates a document snapshot immediately with the curr. The fact that I can get a snapshot back from the server saying document A exists, yet fail a firebase rule for document B that says exists(A), isn't something that I expect to see. Represents a Firestore Database and is the entry point for all Firestore operations (using the methods inherited from Query). Read more about today’s beta launch on the Firebase blog. Now let’s get those records. To begin listening for data, call the startListening() method. I've tested it and it works but there could be a possibility of checking for the same value twice which means the second time it will accept the user since I'm just assuming it's going to. Here we will add all the necessary methods, in order to write, update, read, listen, filter, make a transaction and delete to/from Google Cloud Firestore. What is the actual difference between QueryReference and Snapshot?. 最近Firebaseのことをみてなかったので久々に調べてたらCloud Firestoreという知らないやつがあったので使ってみることにした。 Firebase Cloud Firestore. Overview; auth:import and auth:export; Firebase Realtime Database Operation Types. That’s it guys. We use cookies for various purposes including analytics. The docs say: serverTimestamp: The field must be of type time. Enabling this option causes Firestorter to skip/debounce the first local snapshot, in favor of the full result received slightly later from the cloud. jsでグラフ表示する」は達成できました。. Flutter Firebase App Setup ️ How to setup and configure a new app with FlutterFire for Auth, Firestore, and Analytics In addition to FCM, we will also install Cloud Firestore and Firebase Auth to build a full-stack push notification service. In a project I’m currently working on we’re making use of Google's Firebase to store domain data and run cloud functions. First, we need to make a Firebase query for all user collections with Snapshot. In this example we are going to filter Users older than a selected Age. When you set a listener, Cloud Firestore sends your listener an initial snapshot of the data, and then another snapshot each time the document changes. Currently however the query returns an empty snapshot even though I know that the query should return something. Today we released new versions of our Android (2. These queries can also be used with either get() or addSnapshotListener(), as described above. iBeaconを検知して、そのデータをFirestoreに保存します。 おそらくiBeacon監視のデファクトなAltBeaconでやります。 つづいて保存部分です。 AndroidStudioのFirebaseのアシスタント機能を使ってやり. firestore & storage 사용하기 firestore 에는 문서를 저장하고, storage 에는 파일을 저장합니다. These queries can also be used with either get() or addSnapshotListener(), as described in Get Data and Get Realtime Updates. These examples are extracted from open source projects. A Flutter plugin to use the Cloud Firestore API. We can make use of the next methods over our database references to query our data:. Description Cloud Firestore is an auto-scaling document database for storing, syncing, and querying data for mobile and web apps. I'm making a simple node based forum (although I'm pretty new to Node so it's not that good lol) and I'm trying to query post data from the server to send back to the client. Firebase Guide Part 4: Adding the code to index. In this function we will do the following: 1. firestore에 파일도 저장할 수 있지만 2MiB 제한이 있습니다. 『今回はCloud Firestoreを使ってみましょう 「コレクション」「ドキュメント」「フィールド」 PHPいらなくね?って改めて思ってしまう』自作の小説や楽曲がうっかりちゃっかりひっそり存在しているところです。. Cloud Firestore Plugin for Flutter #. This listener will be notified of all existing data that matches the query and will receive updates in real time. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. A QuerySnapshot contains the results of a query. collection(). We can query the database for all stories that contain a specific tag using Firestore’s array contains query type. Firestore supports offline synchronisation for web apps in addition to mobile apps, whereas the Realtime Database only enables mobile synchronization. Access to data in Cloud Firestore is controlled by Security Rules. firestore 参照型 (3) この最小限のデータベースがCloud Firestoreに保存されているとします。 subCollection1 と subCollection2 名前を取得するにはどうすれば subCollection2 ですか?. An initial call using the callback you provide creates a document snapshot immediately with the. You can also construct refined Query objects by adding filters and ordering. In addition, it is useful to map the document snapshots to their raw data payload at this point to keep the main widget build method free of business logic. I am using async-await for api and not sure how to add a consitional where clause. This happens when some of the query results are loally cached, causing Firestore to fire multiple onSnapshot events. I could find a way to solve this because toList() is not working or i am doing something wrong. Package firestore is an auto-generated package for the Google Cloud Firestore API. This is highly recommended so you can play with the app. I also wrapped the operation with a timer so you can check the latency for a given query. A Flutter plugin to use the Cloud Firestore API. should the user documents have the same id as in Firestore? Query by multiple. 0 リリースノート)。. To me, both seem to like returns the data from the store. [转]firestore: query data Get Realtime Updates with Cloud FirestoreYou can listen to a document with the onSnapshot() method. The number of documents can be determined via the `empty` and `size` properties. Queries and Transactions Realtime Database only supports limited sorting and filtering capabilities—you can only sort or filter on a property level, but not both, in a single query. Since the Firebase team launched Cloud Firestore last week, one question/problem that keeps popping up on Stackoverflow is the result of there being two different ways to retrieve data that have to…. Whether your business is early in its journey or well on its way to digital transformation, Google Cloud's solutions and technologies help chart a path to success. Firestoreで差分(更新された)データのみを取得したい. In addition to returning the snapshot value, the hooks provide an. In turn, this causes Cloud Firestore to notify all listeners with the updated snapshot. collinjackson changed the title Support query with reference field in cloud_firestore. For example, take a snapshot of a "San Francisco" document in your data set of cities and populations. When writing, if the field has the zero value, the server will populate the stored document with the time that the request is processed. firstore 저장소 사용하기 데이터베이스 선택: Clo. FirestoreはRealtime Databaseと同様のデータベースサービス。Realtime DatabaseがJSONで構造化されたデータをストアするのに. Now we even have to disable the persistence, and even then its still slow. Currently that's impossible, because Firestore. The values in the document snapshot serve as the values in the query cursor. The table below shows these types, and the default. Once your data is in Firestore, you probably want to read it at some point. Firestoreはクエリを利用して取得するデータの制限や並び替えを実施することができます。 指定したいクエリをチェーンでつなぎ、左から順に評価して条件にあったデータを取得します。 なお、単一フィールドに対して. Since the Firebase team launched Cloud Firestore last week, one question/problem that keeps popping up on Stackoverflow is the result of there being two different ways to retrieve data that have to…. You can query for documents without having to retrieve all of the other data in other subcollections. js script copying data to?. Timestamp object? or can i query/insert the normal JS Date object and it will get converted automatically? Thanks. We use cookies for various purposes including analytics. Id Dim snapshot As DocumentSnapshot = Await DocLista. It is a super simple cloud NoSQL database. In addition, it is useful to map the document snapshots to their raw data payload at this point to keep the main widget build method free of business logic. sending message to waiting queue (firestore_snapshot) sending message to waiting queue (collection_snapshot) running waiting messages (2) Firestore_Snapshot(com. 最近Firebaseのことをみてなかったので久々に調べてたらCloud Firestoreという知らないやつがあったので使ってみることにした。 Firebase Cloud Firestore. You may want to call this in your onStart() method. Query dan Transaksi. Those properties must be declared in data as well:. A DocumentSnapshot contains data for a single document, while a QuerySnapshot returns data for zero or more documents. // FIXME: if a client modifies _version along with other fields, we won’t create a versioned snapshot. Get all documents in a collection In addition, you can retrieve all documents in a collection by omitting the where() filter entirely:. Today we released new versions of our Android (2. collection(documentName). firstore 저장소 사용하기 데이터베이스 선택: Clo. collinjackson changed the title Support query with reference field in cloud_firestore. 0 リリースノート)。. firestore에 파일도 저장할 수 있지만 2MiB 제한이 있습니다. // Return early if a previous snapshot existed AND its version differs than the current version. I could find a way to solve this because toList() is not working or i am doing something wrong. ele faz uma consulta em um documento firebase Dim Query As Query = docUsuario. This is the Flutter Firestore Tutorial Part 2. Subclassing is not supported in production code and new SDK releases may break code that does so. The number of documents can be determined via the `empty` and `size` properties. Query cursors define the start and end points for a query, allowing you to: Return a subset of the data. // FIXME: if a client modifies _version along with other fields, we won’t create a versioned snapshot. As your app is listening through the StreamBuilder implemented above, it's updated with the new data. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. In addition to returning the snapshot value, the hooks provide an. Realtime Database는 검색 기능이 약해서 전체 포스트(posts)에서 특정 사용자의 포스트만 조회(Query)할 수 없다. I want to query Firestore to get all users WHERE type is admin. Problem: How can I get the Object from the database and how can I check if the query was successfull? I actually can not see if the query found my entry. 我在Doug Stevenson之前经历了这个blog(Firebase开发者倡导者)该博客讨论了如何将firebase实时数据库与android体系结构组件一起使用. , One of the main feature of Firebase is Cloud Firestore, a cloud based real time NoSQL database. Either of these methods can be used with documents, collections of documents, or the results of queries: Call a method to get the data. By default, Cloud Firestore retrieves all documents that satisfy the query in ascending order by document ID, but you can order and limit the data returned. The docs say: serverTimestamp: The field must be of type time. The problem is that it's not sorting by time desc once I store the data in the array. FirestoreはRealtime Databaseと同様のデータベースサービス。Realtime DatabaseがJSONで構造化されたデータをストアするのに. However, to define a specific range for a query, you should use the where() method described in Simple Queries. firestore() const snapshot = await. In Realtime Database, rules cascade. Query the Database by Tag. Flutter Firebase App Setup ️ How to setup and configure a new app with FlutterFire for Auth, Firestore, and Analytics In addition to FCM, we will also install Cloud Firestore and Firebase Auth to build a full-stack push notification service. It is not stable, and may be subject to changes. Firestoreで差分(更新された)データのみを取得したい. Hence you can access first level nodes by their keys (and also any level nodes by their keys) If you're coming from RTDB you'll notice the difference that Cloud Firestore has collections and documents. Get All Documents to get array of Usable Data without Loop in Firestore (self. You can vote up the examples you like and your votes will be used in our system to generate more good examples. Firestore is the better option, as it has a better structure than Realtime Database. The documents can be accessed as an array via the `docs` property or enumerated using the `forEach` method. The usual practice is to query the database directly from the client, but sometimes it's better to route through Cloud Functions. Downloadable Notes See the Cloud Firestore docs for web. To begin listening for data, call the startListening() method. About Me • Twitter、GitHub、Qiita、 SlideShare、Speaker Deck: hironytic • At work:. You can also construct refined Query objects by adding filters and ordering. These queries can also be used with either get() or addSnapshotListener(), as described in Get Data and Get Realtime Updates. rtman changed the title orderBy stops onSnapshot from listening, order incorrect as well [Firestore] orderBy stops onSnapshot from listening, order incorrect as well Nov 1, 2017 This comment has been minimized. Hence you can access first level nodes by their keys (and also any level nodes by their keys) If you're coming from RTDB you'll notice the difference that Cloud Firestore has collections and documents. Get data with Cloud Firestore. In our case, we want to combine both Observable streams of query California and Colorado into 1 single stream: Creating Observables from Firestore snapshots Creating observables from Firestore. In real life, your databases will be more complex and you might use a different kind of a database. collection(documentName). Additionally, it adds the documents id and path to every item. WhereEqualTo("StatusLido", "N") Dim QuerySnapshot As QuerySnapshot = Await Query. Let’s start with the Age filter. The values in the document snapshot serve as the values in the query cursor. Cloud Firestore provides powerful querying, offline enabled SDKs, realtime data synchronization, and all at global scale. They have their own query methods that are way more developer-friendly than the realtimeDB. There is still an escape hatch where the snapshot from Firestore is provided to your render function, in the event that you need more control over your interactions with Firestore. [转]firestore: query data Get Realtime Updates with Cloud FirestoreYou can listen to a document with the onSnapshot() method. Cloud Firestore provides powerful query functionality for specifying which documents you want to retrieve from a collection or collection group. The values in the document snapshot serve as the values in the query cursor. Let’s start with the Age filter. AngularFire2 provides this data in the snapshotChanges() method, making it possible to map custom objects that have the raw snapshot we need as a cursor. We use cookies for various purposes including analytics. Simple two-way(ish) binding of firestore docs and collections to vue computed properties. I have a node websocket listener set to query some data from my database. Microsoft Azure Cosmos DB Please select another system to include it in the comparison. Cloud Firestore helps us store data in the cloud. Currently however the query returns an empty snapshot even though I know that the query should return something. How it Works. query property in the order they will be chained with the query method as the only property and it's value being an array of arguments, or a single string value as show below. You may want to call this in your onStart() method. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. Cloud Firestore queries are shallow, so when you make a query to a document, it will not have a sub-collection on it. Then, use that. We'll talk more about rules later in this codelab but first we need to set some basic rules on our data to get started. NOTE: This package is in beta. firestore & storage 사용하기 firestore 에는 문서를 저장하고, storage 에는 파일을 저장합니다. こちらの続編です。 kojimainjp. Overview; auth:import and auth:export; Firebase Realtime Database Operation Types. A Query which you can read or listen to. Firebase) submitted 1 year ago by glddigga49 Hi, I have been looking everywhere to find a solution to my issue, and was wondering if anyone had come across the same problem yet. To begin querying data in Firestore you must first fill in the Project Id property on the Resource screen. js script copying data to?. using this firestore instance we are accessing/ fetching the data from Firebase Database. Cloud Firestore を使う利点の一つにリアルタイムに変更を取得できる点が挙げられます。公式ドキュメントでは Go SDK はまだサポートされていないと書かれていますが(2018/12/5 時点)、機能自体は SDK に実装されています (v0. Core Developer. Cloud Firestore provides powerful query functionality for specifying which documents you want to retrieve from a collection. Call Next on the iterator to get a snapshot of the query's results each. Create a DocumentReference that points to the document you want. To begin listening for data, call the startListening() method. API docs for the QuerySnapshot class from the cloud_firestore library, for the Dart programming language. You can also construct refined Query objects by adding filters and ordering. In addition to returning the snapshot value, the hooks provide an. As your app is listening through the StreamBuilder implemented above, it's updated with the new data. I could find a way to solve this because toList() is not working or i am doing something wrong. Adding a snapshot listener to a collection with 4000 documents returns data in appr. This option is only available after installing firestorePlugin. 新しいKindに対するオペレーションは毎秒 500 回を上限とし、その後でトラフィックを50%ずつ、5 分ごとに増やしていく. A `QuerySnapshot` contains zero or more `DocumentSnapshot` objects representing the results of a query. What is the actual difference between QueryReference and Snapshot?. Either of these methods can be used with documents, collections of documents, or the results of queries: Call a method to get the data. collection(documentName). collinjackson changed the title Support query with reference field in cloud_firestore. This library, on the other hand, doesn't attempt to wrap all the API's, but. To begin listening for data, call the startListening() method.