app-service-mobile-update-server-project-for-push-template.md

In this section, you update code in your existing Mobile Apps back-end project to send a push notification every time a new item is added. This is powered by the template feature of Azure Notification Hubs, enabling cross-platform pushes. The various clients are registered for push notifications using templates, and a single universal push can get to all client platforms.

Choose one of the following procedures that matches your back-end project type—either .NET back end or Node.js back end.

.NET back-end project

1. In Visual Studio, right-click the server project and click Manage NuGet Packages. Search for Microsoft.Azure.NotificationHubs, and then click Install. This installs the Notification Hubs library for sending notifications from your back end.

2. In the server project, open Controllers > TodoItemController.cs, and add the following using statements:

    using System.Collections.Generic;
    using Microsoft.Azure.NotificationHubs;
    using Microsoft.Azure.Mobile.Server.Config;
   

3. In the PostTodoItem method, add the following code after the call to InsertAsync:

    // Get the settings for the server project.
    HttpConfiguration config = this.Configuration;
    MobileAppSettingsDictionary settings =
        this.Configuration.GetMobileAppSettingsProvider().GetMobileAppSettings();
   
    // Get the Notification Hubs credentials for the Mobile App.
    string notificationHubName = settings.NotificationHubName;
    string notificationHubConnection = settings
        .Connections[MobileAppSettingsKeys.NotificationHubConnectionString].ConnectionString;
   
    // Create a new Notification Hub client.
    NotificationHubClient hub = NotificationHubClient
    .CreateClientFromConnectionString(notificationHubConnection, notificationHubName);
   
    // Sending the message so that all template registrations that contain "messageParam"
    // will receive the notifications. This includes APNS, GCM, WNS, and MPNS template registrations.
    Dictionary<string,string> templateParams = new Dictionary<string,string>();
    templateParams["messageParam"] = item.Text + " was added to the list.";
   
    try
    {
        // Send the push notification and log the results.
        var result = await hub.SendTemplateNotificationAsync(templateParams);
   
        // Write the success result to the logs.
        config.Services.GetTraceWriter().Info(result.State.ToString());
    }
    catch (System.Exception ex)
    {
        // Write the failure result to the logs.
        config.Services.GetTraceWriter()
            .Error(ex.Message, null, "Push.SendAsync Error");
    }
   

   This sends a template notification that contains the item.Text when a new item is inserted.

4. Republish the server project.

Node.js back-end project

1. If you haven't already done so, download the quickstart back-end project, or else use the online editor in the Azure portal.

2. Replace the existing code in todoitem.js with the following:

    var azureMobileApps = require('azure-mobile-apps'),
    promises = require('azure-mobile-apps/src/utilities/promises'),
    logger = require('azure-mobile-apps/src/logger');
   
    var table = azureMobileApps.table();
   
    table.insert(function (context) {
    // For more information about the Notification Hubs JavaScript SDK,
    // see http://aka.ms/nodejshubs
    logger.info('Running TodoItem.insert');
   
    // Define the template payload.
    var payload = '{"messageParam": "' + context.item.text + '" }';  
   
    // Execute the insert.  The insert returns the results as a Promise,
    // Do the push as a post-execute action within the promise flow.
    return context.execute()
        .then(function (results) {
            // Only do the push if configured
            if (context.push) {
                // Send a template notification.
                context.push.send(null, payload, function (error) {
                    if (error) {
                        logger.error('Error while sending push notification: ', error);
                    } else {
                        logger.info('Push notification sent successfully!');
                    }
                });
            }
            // Don't forget to return the results from the context.execute()
            return results;
        })
        .catch(function (error) {
            logger.error('Error while running context.execute: ', error);
        });
    });
   
    module.exports = table;  
   

   This sends a template notification that contains the item.text when a new item is inserted.

3. When editing the file on your local computer, republish the server project.