Pesan topik di C++

Berdasarkan model publikasi/langganan, pesan topik FCM dapat digunakan untuk mengirim pesan ke beberapa perangkat yang mengikuti topik tertentu. Anda cukup menulis pesan topik sesuai kebutuhan dan FCM akan secara andal menangani perutean serta pengiriman pesan ke perangkat yang tepat.

Misalnya, pengguna suatu aplikasi perkiraan pasang surut laut setempat dapat memilih untuk menerima topik "pemberitahuan arus pasang surut" dan menerima notifikasi kondisi laut yang optimal untuk menangkap ikan di area tertentu. Pengguna suatu aplikasi olahraga dapat berlangganan untuk menerima update terbaru secara otomatis terkait skor pertandingan langsung tim favoritnya.

Beberapa hal yang perlu diingat tentang topik:

• Pesan topik paling cocok untuk konten seperti cuaca, atau informasi lainnya yang tersedia untuk umum.
• Pesan topik dioptimalkan untuk throughput, bukan latensi. Untuk mengirim dengan cepat dan aman ke satu perangkat atau sekelompok kecil perangkat, targetkan pesan ke token pendaftaran, bukan topik.
• Jika Anda perlu mengirimkan pesan ke beberapa perangkat per pengguna, sebaiknya gunakan pesan grup perangkat untuk kasus penggunaan tersebut.
• Pesan topik mendukung langganan tak terbatas untuk setiap topik. Namun, FCM memberlakukan batasan untuk hal-hal berikut:
  • Satu instance aplikasi hanya dapat berlangganan maksimal 2.000 topik.
  • Jika Anda menggunakan impor batch untuk membuat instance aplikasi berlangganan topik, setiap permintaan dibatasi hingga 1.000 instance aplikasi.
  • Frekuensi langganan baru dibatasi kapasitasnya per project. Jika Anda mengirim terlalu banyak permintaan langganan dalam waktu singkat, server FCM akan memberikan respons 429 RESOURCE_EXHAUSTED ("kuota terlampaui"). Coba lagi dengan backoff eksponensial.

Membuat aplikasi klien berlangganan topik

Untuk berlangganan topik, panggil ::firebase::messaging::Subscribe dari aplikasi Anda. Panggilan ini mengirimkan permintaan asinkron ke backend FCM dan membuat klien berlangganan topik yang ditentukan.

::firebase::messaging::Subscribe("example");

Jika awalnya permintaan langganan gagal, FCM akan mencoba kembali hingga klien berhasil berlangganan topik tersebut. Setiap kali aplikasi dimulai, FCM akan memastikan bahwa klien telah berlangganan semua topik yang diminta.

Untuk menghentikan langganan, panggil ::firebase::messaging::Unsubscribe, dan FCM akan menghentikan langganan topik di latar belakang.

Mengelola langganan topik di server

Firebase Admin SDK dapat Anda gunakan untuk menjalankan tugas dasar pengelolaan topik dari sisi server. Dengan token pendaftaran instance, Anda dapat membuat instance aplikasi klien berlangganan dan berhenti berlangganan secara massal menggunakan logika server.

Anda dapat membuat instance aplikasi klien berlangganan topik yang ada, atau Anda dapat membuat topik baru. Jika Anda menggunakan API untuk membuat aplikasi klien berlangganan topik baru (topik yang belum ada untuk project Firebase Anda), topik baru dengan nama tersebut akan dibuat di FCM sehingga semua klien dapat berlangganan topik tersebut.

Anda dapat meneruskan daftar token pendaftaran ini ke metode langganan Firebase Admin SDK agar perangkat terkait ikut berlangganan topik:

Node.js

// These registration tokens come from the client FCM SDKs.
const registrationTokens = [
  'YOUR_REGISTRATION_TOKEN_1',
  // ...
  'YOUR_REGISTRATION_TOKEN_n'
];

// Subscribe the devices corresponding to the registration tokens to the
// topic.
getMessaging().subscribeToTopic(registrationTokens, topic)
  .then((response) => {
    // See the MessagingTopicManagementResponse reference documentation
    // for the contents of response.
    console.log('Successfully subscribed to topic:', response);
  })
  .catch((error) => {
    console.log('Error subscribing to topic:', error);
  });

Java

// These registration tokens come from the client FCM SDKs.
List<String> registrationTokens = Arrays.asList(
    "YOUR_REGISTRATION_TOKEN_1",
    // ...
    "YOUR_REGISTRATION_TOKEN_n"
);

// Subscribe the devices corresponding to the registration tokens to the
// topic.
TopicManagementResponse response = FirebaseMessaging.getInstance().subscribeToTopic(
    registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
System.out.println(response.getSuccessCount() + " tokens were subscribed successfully");

Python

# These registration tokens come from the client FCM SDKs.
registration_tokens = [
    'YOUR_REGISTRATION_TOKEN_1',
    # ...
    'YOUR_REGISTRATION_TOKEN_n',
]

# Subscribe the devices corresponding to the registration tokens to the
# topic.
response = messaging.subscribe_to_topic(registration_tokens, topic)
# See the TopicManagementResponse reference documentation
# for the contents of response.
print(response.success_count, 'tokens were subscribed successfully')

Go

// These registration tokens come from the client FCM SDKs.
registrationTokens := []string{
	"YOUR_REGISTRATION_TOKEN_1",
	// ...
	"YOUR_REGISTRATION_TOKEN_n",
}

// Subscribe the devices corresponding to the registration tokens to the
// topic.
response, err := client.SubscribeToTopic(ctx, registrationTokens, topic)
if err != nil {
	log.Fatalln(err)
}
// See the TopicManagementResponse reference documentation
// for the contents of response.
fmt.Println(response.SuccessCount, "tokens were subscribed successfully")

C#

// These registration tokens come from the client FCM SDKs.
var registrationTokens = new List<string>()
{
    "YOUR_REGISTRATION_TOKEN_1",
    // ...
    "YOUR_REGISTRATION_TOKEN_n",
};

// Subscribe the devices corresponding to the registration tokens to the
// topic
var response = await FirebaseMessaging.DefaultInstance.SubscribeToTopicAsync(
    registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
Console.WriteLine($"{response.SuccessCount} tokens were subscribed successfully");
FirebaseMessagingSnippets.cs

Penting: Untuk menggunakan Admin FCM API, Anda harus terlebih dahulu mengikuti langkah-langkah yang tercantum di artikel Menambahkan Firebase Admin SDK ke Server untuk menginisialisasi SDK tersebut.

Dengan Admin FCM API, Anda juga dapat menghentikan langganan perangkat dari sebuah topik dengan meneruskan token pendaftaran ke metode yang sesuai:

Node.js

// These registration tokens come from the client FCM SDKs.
const registrationTokens = [
  'YOUR_REGISTRATION_TOKEN_1',
  // ...
  'YOUR_REGISTRATION_TOKEN_n'
];

// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
getMessaging().unsubscribeFromTopic(registrationTokens, topic)
  .then((response) => {
    // See the MessagingTopicManagementResponse reference documentation
    // for the contents of response.
    console.log('Successfully unsubscribed from topic:', response);
  })
  .catch((error) => {
    console.log('Error unsubscribing from topic:', error);
  });

Java

// These registration tokens come from the client FCM SDKs.
List<String> registrationTokens = Arrays.asList(
    "YOUR_REGISTRATION_TOKEN_1",
    // ...
    "YOUR_REGISTRATION_TOKEN_n"
);

// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
TopicManagementResponse response = FirebaseMessaging.getInstance().unsubscribeFromTopic(
    registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
System.out.println(response.getSuccessCount() + " tokens were unsubscribed successfully");

Python

# These registration tokens come from the client FCM SDKs.
registration_tokens = [
    'YOUR_REGISTRATION_TOKEN_1',
    # ...
    'YOUR_REGISTRATION_TOKEN_n',
]

# Unubscribe the devices corresponding to the registration tokens from the
# topic.
response = messaging.unsubscribe_from_topic(registration_tokens, topic)
# See the TopicManagementResponse reference documentation
# for the contents of response.
print(response.success_count, 'tokens were unsubscribed successfully')

Go

// These registration tokens come from the client FCM SDKs.
registrationTokens := []string{
	"YOUR_REGISTRATION_TOKEN_1",
	// ...
	"YOUR_REGISTRATION_TOKEN_n",
}

// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
response, err := client.UnsubscribeFromTopic(ctx, registrationTokens, topic)
if err != nil {
	log.Fatalln(err)
}
// See the TopicManagementResponse reference documentation
// for the contents of response.
fmt.Println(response.SuccessCount, "tokens were unsubscribed successfully")

C#

// These registration tokens come from the client FCM SDKs.
var registrationTokens = new List<string>()
{
    "YOUR_REGISTRATION_TOKEN_1",
    // ...
    "YOUR_REGISTRATION_TOKEN_n",
};

// Unsubscribe the devices corresponding to the registration tokens from the
// topic
var response = await FirebaseMessaging.DefaultInstance.UnsubscribeFromTopicAsync(
    registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
Console.WriteLine($"{response.SuccessCount} tokens were unsubscribed successfully");
FirebaseMessagingSnippets.cs

Catatan: Anda dapat membuat maksimum 1.000 perangkat berlangganan atau berhenti berlangganan dalam satu permintaan. Jika Anda memasukkan lebih dari 1.000 token pendaftaran ke array, permintaan akan gagal dengan menampilkan error messaging/invalid-argument.

Metode subscribeToTopic() dan unsubscribeFromTopic() menghasilkan objek yang berisi respons dari FCM. Jenis nilai yang ditampilkan memiliki format yang sama berapa pun jumlah token pendaftaran yang ditentukan dalam permintaan.

Jika terjadi error (kegagalan autentikasi, token atau topik tidak valid, dll.), metode ini akan mengakibatkan error. Untuk mengetahui daftar lengkap kode error, termasuk deskripsi dan langkah penyelesaian, baca bagian Error Admin FCM API.

Menerima dan menangani pesan topik

FCM mengirim pesan topik dengan cara yang sama seperti pesan downstream lainnya.

Dengan mengganti metode ::firebase::messaging::Listener::OnMessage, Anda dapat melakukan tindakan berdasarkan pesan yang diterima dan mendapatkan data pesan:

void OnMessage(const ::firebase::messaging::Message& message) {
  LogMessage(TAG, "From: %s", message.from.c_str());
  LogMessage(TAG, "Message ID: %s", message.message_id.c_str());
}

Mem-build permintaan kirim

Setelah membuat topik, baik dengan membuat instance aplikasi klien berlangganan topik di sisi klien maupun melalui API server, Anda dapat mengirim pesan ke topik tersebut. Jika ini adalah pertama kalinya Anda mem-build permintaan kirim untuk FCM, baca panduan lingkungan server dan FCM untuk mengetahui informasi penting tentang penyiapan dan latar belakang.

Dalam logika pengiriman Anda di backend, tentukan nama topik yang diinginkan seperti yang ditunjukkan di bawah:

Node.js

// The topic name can be optionally prefixed with "/topics/".
const topic = 'highScores';

const message = {
  data: {
    score: '850',
    time: '2:45'
  },
  topic: topic
};

// Send a message to devices subscribed to the provided topic.
getMessaging().send(message)
  .then((response) => {
    // Response is a message ID string.
    console.log('Successfully sent message:', response);
  })
  .catch((error) => {
    console.log('Error sending message:', error);
  });

Java

// The topic name can be optionally prefixed with "/topics/".
String topic = "highScores";

// See documentation on defining a message payload.
Message message = Message.builder()
    .putData("score", "850")
    .putData("time", "2:45")
    .setTopic(topic)
    .build();

// Send a message to the devices subscribed to the provided topic.
String response = FirebaseMessaging.getInstance().send(message);
// Response is a message ID string.
System.out.println("Successfully sent message: " + response);
FirebaseMessagingSnippets.java

Python

# The topic name can be optionally prefixed with "/topics/".
topic = 'highScores'

# See documentation on defining a message payload.
message = messaging.Message(
    data={
        'score': '850',
        'time': '2:45',
    },
    topic=topic,
)

# Send a message to the devices subscribed to the provided topic.
response = messaging.send(message)
# Response is a message ID string.
print('Successfully sent message:', response)
cloud_messaging.py

Go

// The topic name can be optionally prefixed with "/topics/".
topic := "highScores"

// See documentation on defining a message payload.
message := &messaging.Message{
	Data: map[string]string{
		"score": "850",
		"time":  "2:45",
	},
	Topic: topic,
}

// Send a message to the devices subscribed to the provided topic.
response, err := client.Send(ctx, message)
if err != nil {
	log.Fatalln(err)
}
// Response is a message ID string.
fmt.Println("Successfully sent message:", response)
messaging.go

C#

// The topic name can be optionally prefixed with "/topics/".
var topic = "highScores";

// See documentation on defining a message payload.
var message = new Message()
{
    Data = new Dictionary<string, string>()
    {
        { "score", "850" },
        { "time", "2:45" },
    },
    Topic = topic,
};

// Send a message to the devices subscribed to the provided topic.
string response = await FirebaseMessaging.DefaultInstance.SendAsync(message);
// Response is a message ID string.
Console.WriteLine("Successfully sent message: " + response);

REST

POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1

Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
  "message":{
    "topic" : "foo-bar",
    "notification" : {
      "body" : "This is a Firebase Cloud Messaging Topic Message!",
      "title" : "FCM Message"
      }
   }
}

Perintah cURL:

curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
  "message": {
    "topic" : "foo-bar",
    "notification": {
      "body": "This is a Firebase Cloud Messaging Topic Message!",
      "title": "FCM Message"
    }
  }
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1

Untuk mengirim pesan ke kombinasi topik, tentukan kondisi, yang merupakan ekspresi boolean yang menentukan topik target. Misalnya, kondisi berikut akan mengirim pesan ke perangkat yang berlangganan TopicA dan juga TopicB atau TopicC:

"'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)"

FCM mengevaluasi terlebih dahulu setiap kondisi di dalam tanda kurung, lalu mengevaluasi ekspresi dari kiri ke kanan. Pada ekspresi di atas, pengguna yang hanya berlangganan satu topik apa pun tidak akan menerima pesan. Demikian pula, pengguna yang tidak berlangganan TopicA tidak akan menerima pesan. Namun, pengguna dengan kombinasi berikut akan menerimanya:

• TopicA dan TopicB
• TopicA dan TopicC

Anda dapat menyertakan hingga lima topik dalam ekspresi kondisional.

Untuk mengirim ke sebuah kondisi:

Node.js

// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
const condition = '\'stock-GOOG\' in topics || \'industry-tech\' in topics';

// See documentation on defining a message payload.
const message = {
  notification: {
    title: '$FooCorp up 1.43% on the day',
    body: '$FooCorp gained 11.80 points to close at 835.67, up 1.43% on the day.'
  },
  condition: condition
};

// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
getMessaging().send(message)
  .then((response) => {
    // Response is a message ID string.
    console.log('Successfully sent message:', response);
  })
  .catch((error) => {
    console.log('Error sending message:', error);
  });

Java

// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
String condition = "'stock-GOOG' in topics || 'industry-tech' in topics";

// See documentation on defining a message payload.
Message message = Message.builder()
    .setNotification(Notification.builder()
        .setTitle("$GOOG up 1.43% on the day")
        .setBody("$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.")
        .build())
    .setCondition(condition)
    .build();

// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
String response = FirebaseMessaging.getInstance().send(message);
// Response is a message ID string.
System.out.println("Successfully sent message: " + response);
FirebaseMessagingSnippets.java

Python

# Define a condition which will send to devices which are subscribed
# to either the Google stock or the tech industry topics.
condition = "'stock-GOOG' in topics || 'industry-tech' in topics"

# See documentation on defining a message payload.
message = messaging.Message(
    notification=messaging.Notification(
        title='$GOOG up 1.43% on the day',
        body='$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.',
    ),
    condition=condition,
)

# Send a message to devices subscribed to the combination of topics
# specified by the provided condition.
response = messaging.send(message)
# Response is a message ID string.
print('Successfully sent message:', response)
cloud_messaging.py

Go

// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
condition := "'stock-GOOG' in topics || 'industry-tech' in topics"

// See documentation on defining a message payload.
message := &messaging.Message{
	Data: map[string]string{
		"score": "850",
		"time":  "2:45",
	},
	Condition: condition,
}

// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
response, err := client.Send(ctx, message)
if err != nil {
	log.Fatalln(err)
}
// Response is a message ID string.
fmt.Println("Successfully sent message:", response)
messaging.go

C#

// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
var condition = "'stock-GOOG' in topics || 'industry-tech' in topics";

// See documentation on defining a message payload.
var message = new Message()
{
    Notification = new Notification()
    {
        Title = "$GOOG up 1.43% on the day",
        Body = "$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.",
    },
    Condition = condition,
};

// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
string response = await FirebaseMessaging.DefaultInstance.SendAsync(message);
// Response is a message ID string.
Console.WriteLine("Successfully sent message: " + response);

REST

POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1

Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
   "message":{
    "condition": "'dogs' in topics || 'cats' in topics",
    "notification" : {
      "body" : "This is a Firebase Cloud Messaging Topic Message!",
      "title" : "FCM Message",
    }
  }
}

Perintah cURL:

curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
  "notification": {
    "title": "FCM Message",
    "body": "This is a Firebase Cloud Messaging Topic Message!",
  },
  "condition": "'dogs' in topics || 'cats' in topics"
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1