Quickstart: Publish messages using the Azure Web PubSub service SDK

Install both the .NET Core SDK and the aspnetcore and dotnet runtime.

.NET Core

Node.js

Python

• Java Development Kit (JDK)
• Apache Maven

RESOURCE_GROUP="webpubsub-resource-group"
LOCATION="EastUS"
WEB_PUBSUB_NAME="<your-unique-name>"

$ResourceGroupName = 'webpubsub-resource-group'
$Location = 'EastUS'
$WebPubSubName = '<YourUniqueName>'

az group create \
  --name $RESOURCE_GROUP \
  --location $LOCATION

az group create --location $Location --name $ResourceGroupName

az webpubsub create \
  --name $WEB_PUBSUB_NAME \
  --resource-group $RESOURCE_GROUP \
  --location $LOCATION \
  --sku Free_F1

az webpubsub create `
  --name $WebPubSubName `
  --location $Location `
  --resource-group $ResourceGroupName `
  --sku Free_F1

az webpubsub key show --name $WEB_PUBSUB_NAME --resource-group $RESOURCE_GROUP --query primaryConnectionString

az webpubsub key show --name $WebPubSubName --resource-group $ResourceGroupName --query primaryConnectionString

az webpubsub client start \
  --name $WEB_PUBSUB_NAME \
  --resource-group $RESOURCE_GROUP \
  --hub-name "myHub1" \
  --user-id "user1"

az webpubsub client start `
  --name $WebPubSubName `
  --resource-group $ResourceGroupName `
  --hub-name 'myHub1' `
  --user-id 'user1' 

1. Add a new project named publisher and the SDK package Azure.Messaging.WebPubSub.

   mkdir publisher
   cd publisher
   dotnet new console
   dotnet add package Azure.Messaging.WebPubSub
   

2. Update the Program.cs file to use the WebPubSubServiceClient class to send messages to the clients. Replace the code in the Program.cs file with the following code.

   using System;
   using System.Threading.Tasks;
   using Azure.Messaging.WebPubSub;
   
   namespace publisher
   {
       class Program
       {
           static async Task Main(string[] args)
           {
               if (args.Length != 3) {
                   Console.WriteLine("Usage: publisher <connectionString> <hub> <message>");
                   return;
               }
               var connectionString = args[0];
               var hub = args[1];
               var message = args[2];
   
               var service = new WebPubSubServiceClient(connectionString, hub);
   
               // Send messages to all the connected clients
               // You can also try SendToConnectionAsync to send messages to the specific connection
               await service.SendToAllAsync(message);
           }
       }
   }
   

   The service.SendToAllAsync() call simply sends a message to all connected clients in the hub.

3. Run the following command to publish a message to the service.

   dotnet run $connection_string "myHub1" "Hello World"
   

4. The previous command shell containing the Web PubSub client shows the received message.

   {"type":"message","from":"server","dataType":"text","data":"Hello World"}
   

1. Create a new folder named publisher for this project and install required dependencies:

   mkdir publisher
   cd publisher
   npm init -y
   npm install --save @azure/web-pubsub
   

2. Use Azure Web PubSub SDK to publish a message to the service. Create a publish.js file containing the code:

   const { WebPubSubServiceClient } = require('@azure/web-pubsub');
   
   if (process.argv.length !== 3) {
     console.log('Usage: node publish <message>');
     return 1;
   }
   const hub = "myHub1";
   let service = new WebPubSubServiceClient(process.env.WebPubSubConnectionString, hub);
   // by default it uses `application/json`, specify contentType as `text/plain` if you want plain-text
   service.sendToAll(process.argv[2], { contentType: "text/plain" });
   

   The sendToAll() call simply sends a message to all connected clients in a hub.

3. Run the following command to publish a message to the service:

   export WebPubSubConnectionString=$connection_string
   node publish "Hello World"
   

4. The previous command shell containing the Web PubSub client shows the received message.

   {"type":"message","from":"server","dataType":"text","data":"Hello World"}
   

1. Create a new folder named publisher for this project and install required dependencies:

   mkdir publisher
   cd publisher
   # Create venv
   python -m venv env
   # Active venv
   source ./env/bin/activate
   pip install azure-messaging-webpubsubservice
   

2. Use Azure Web PubSub SDK to publish a message to the service. Create a publish.py file with the below code:

   import sys
   from azure.messaging.webpubsubservice import WebPubSubServiceClient
   
   if __name__ == '__main__':
   
       if len(sys.argv) != 4:
           print('Usage: python publish.py <connection-string> <hub-name> <message>')
           exit(1)
   
       connection_string = sys.argv[1]
       hub_name = sys.argv[2]
       message = sys.argv[3]
   
       service = WebPubSubServiceClient.from_connection_string(connection_string, hub=hub_name)
       res = service.send_to_all(message, content_type='text/plain')
       print(res)
   

   The service.send_to_all() method sends the message to all connected clients in a hub.

3. Run the following command to publish a message to the service:

   python publish.py $connection_string "myHub1" "Hello World"
   

4. The previous command shell containing the Web PubSub client shows the received message.

   {"type":"message","from":"server","dataType":"text","data":"Hello World"}
   

1. Use Maven to create a new console app named webpubsub-quickstart-publisher and go to the webpubsub-quickstart-publisher directory:

   mvn archetype:generate --define interactiveMode=n --define groupId=com.webpubsub.quickstart --define artifactId=webpubsub-quickstart-publisher --define archetypeArtifactId=maven-archetype-quickstart --define archetypeVersion=1.4
   cd webpubsub-quickstart-publisher
   

2. Add the Azure Web PubSub SDK to the dependencies node of pom.xml:

   <dependency>
       <groupId>com.azure</groupId>
       <artifactId>azure-messaging-webpubsub</artifactId>
       <version>1.0.0</version>
   </dependency>
   

3. Go to the src/main/java/com/webpubsub/quickstart directory.

4. Replace the contents in the App.java file with the following code:

   package com.webpubsub.quickstart;
   
   import com.azure.messaging.webpubsub.*;
   import com.azure.messaging.webpubsub.models.*;
   
   /**
   * Publish messages using Azure Web PubSub service SDK
   *
   */
   public class App 
   {
       public static void main( String[] args )
       {
           if (args.length != 3) {
               System.out.println("Expecting 3 arguments: <connection-string> <hub-name> <message>");
               return;
           }
   
           WebPubSubServiceClient service = new WebPubSubServiceClientBuilder()
               .connectionString(args[0])
               .hub(args[1])
               .buildClient();
           service.sendToAll(args[2], WebPubSubContentType.TEXT_PLAIN);
       }
   }
   
   

   This code uses the Azure Web PubSub SDK to publish a message to the service. The service.sendToAll() call sends a message to all connected clients in a hub.

5. Return t the webpubsub-quickstart-publisher directory containing the pom.xml file and compile the project by using the following mvn command.

   mvn compile
   

6. Build the package.

   mvn package
   

7. Run the following mvn command to execute the app to publish a message to the service:

   mvn exec:java -Dexec.mainClass="com.webpubsub.quickstart.App" -Dexec.cleanupDaemonThreads=false -Dexec.args=" '$connection_string' 'myHub1' 'Hello World'"
   

8. The previous command shell containing the Web PubSub client shows the received message.

   {"type":"message","from":"server","dataType":"text","data":"Hello World"}
   

az group delete --name $RESOURCE_GROUP --yes

d

az group delete --name $ResourceGroup --yes

Next steps

This quickstart provides you a basic idea of how to connect to the Web PubSub service and how to publish messages to the connected clients.

In real-world applications, you can use SDKs in various languages build your own application. We also provide Function extensions for you to build serverless applications easily.

Use these resources to start building your own application: