How can I send message to multiple tokens?

[bytefish]

You have create a message for each of your registration tokens. The Firebase Messaging v1 API does not have something like a specific Multicast message. Creating a message for each token is what Google does in the Firebase SDK for Java:

• https://github.com/firebase/firebase-admin-java/blob/e19ca297ad8314fef180e3822840bba80ab9f69c/src/main/java/com/google/firebase/messaging/MulticastMessage.java#L67

[ianmark89]

So I have create new method in FCM client for sending list of messages?

[bytefish]

Let me see, if I can add an extension method to the library. Give me a moment. 👍

[bytefish]

Oh look how wrong I was!

There is actually a Batch Endpoint!

[bytefish]

I will implement it, but it may take a day. 👍 Thanks for raising the issue. I didn't even know, that Request Batching is supported. That makes a great feature. 👍 What do you think about releasing it with 3.0? Then I can correct some questionable design decisions in the API.

[bytefish]

I think the simplest approach is to see, what they did in the TypeScript implementation:

• https://github.com/firebase/firebase-admin-node/blob/bf3dbd117ffc3c895a150eee2169eb7c02f4f4cc/src/messaging/batch-request.ts

I had a look into the Google .NET Client Implementation, there is actually a BatchRequest class. But it's so overdesigned, I don't really want to use it. I think for this Firebase API implementation it is better to keep it simple and duplicate it.

That makes it easier for me to understand it and better to maintain!

[bytefish]

Added the SendBatch Method in 3.0.0 to send Messages to Multiple Devices in one request. Thanks for the nice feature. 👍

[bytefish]

I have added a method SendMulticastMessage to the API. Sending a Multicast message is now as easy as writing:

var result = client.SendMulticastMessage(tokens, message)

Here is a full example:

// Copyright (c) Philipp Wagner. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System.IO;
using System.Threading;
using FcmSharp.Requests;
using FcmSharp.Settings;
using NUnit.Framework;

namespace FcmSharp.Test.Integration
{
    [TestFixture]
    class BatchMessageIntegrationTest
    {
        [Test]
        public void SendBatchMessages()
        {
            // This is a list of Tokens I want to send the Batch Message to:
            var tokens = File.ReadAllLines(@"D:\device_tokens.txt");

            // Read the Credentials from a File, which is not under Version Control:
            var settings = FileBasedFcmClientSettings.CreateFromFile(@"D:\serviceAccountKey.json");

            // Construct the Client:
            using (var client = new FcmClient(settings))
            {

                Message message = new Message
                {
                    Notification = new Notification
                    {
                        Title = "Notification Title",
                        Body = "Notification Body Text"
                    }
                };

                // Finally send the Message and wait for the Result:
                CancellationTokenSource cts = new CancellationTokenSource();

                // Send the Message and wait synchronously:
                var result = client.SendMulticastMessage(tokens, message, false, cts.Token).GetAwaiter().GetResult();

                // Print the Result to the Console:
                foreach (var response in result.Responses)
                {
                    Assert.IsNotNull(response.Name);
                }
            }
        }
    }
}