How would I communicate between two separate hubs?
So Hub1 is my ChatHub for Support Agents and Hub2 is my Hub for customers.
Support agents have logins, customers have a form they fill out which creates a user and so on. But how can I pass the user created from Hub2 to Hub1 for all the users who have a Hub1(Support Agents) or is there some better way to do this?
Would I need to handle it all in Hub1 with some logic for differentiating between customers and agents?
May not be possible since the Hubs aren't static they are created per user right?
The problem with doing it all in one Hub is after the form is filled out it sends them to another page so they get a new connectionId and they have no Context.User.Identity.Name so there is no way to grab them again since I don't know their information from the new page.
You can use GlobalHost.ConnectionManager for communicating between Hubs:
var ctx = GlobalHost.ConnectionManager.GetHubContext<HubName>();
ctx.Clients.All.methodName(parameter);
Related
In the article describing the registration management it states that:
The following are some key advantages to using installations:
Creating or updating an installation is fully idempotent. So you can
retry it without any concerns about duplicate registrations
What does it exactly mean? I assume it doesn't mean the installations have a 'CreateOrUpdate' unlike registrations, because a similar method also exists there - 'CreateOrUpdateRegistrationAsync'.
Suppose that I've created two installations with different installation ID but the same PNS handle (pushChannel property) and identical tag 'foo' present in both installations. I'm going to send a notification using the SendTemplateNotificationAsync method using the 'foo' tag to select the target of my notification.
It's going to match both my installations, because they both contain the tag 'foo' and both have the same PNS handle. Is the device going to receive two notifications, or is Azure going to prevent delivery of duplicates in this case?
In the the same article I've linked the code samples do check for existing registrations with the PNS handle that's about to get registered:
// make sure there are no existing registrations for this push handle (used for iOS and Android)
string newRegistrationId = null;
var registrations = await hub.GetRegistrationsByChannelAsync(pushChannel.Uri, 100);
but they don't check that in the installations samples, which again suggests that Azure prevents delivery of duplicate notifications.
Creating or updating an installation is fully idempotent. So you can
retry it without any concerns about duplicate registrations
Here, an installation is a term used to describe an enhanced registration (with Azure's Notification Hub) to associate PNS of the device with tag(s) and/or template(s). "Idempotency" here is used with regards to the act of such an installation.
What it means is that you can simply call the same code for this type of registration every time your app starts or is brought to foreground without worrying about handling changes in PNS or previous states of registration with the Notification Hub.
This is good because the classic registration model can lead to duplicate registrations for the same device and user in the notification hub. Installation model doesn't do that.
Q. What would happen when you have one PNS assigned to multiple registrations with same tag in the Notification Hub and you try to push a notification by targeting a tag?
A. Azure Notification Hub has de-duplication logic which will prevent duplicate notifications from going out.
Q. Can you force multiple notifications (for the same tag) in any way if you have multiple applications but one Notification Hub?
A. You can if you can get multiple device tokens. However, in case of iOS, as APNS issues only one valid device token at a time, it will not be possible. Also, iOS apps have their own bundle identifier and therefore their own specific push certificate. And, Notification Hubs don't support multiple certificates. But in case of Android, you can force it if you use registration model and use older GCM registration Ids as they are renewed frequently and don't expire so easily.
Hope that helps! Cheers!
I have an application that serves multiple customers. As part of my workflow, I would like to use PubNub for realtime messaging to customers, offering something like one channel per customer. I would like to just give my customers a subscription key that they can use to listen to messages on their particular channel.
Is this a supported scenario on Pubnub? What’s the right way to set this up? I assume that I will do all the setup on my side and also handle all the billing, while just handing my customers the subscription keys to their channels. But for now, on my Pubnub account, I only see one “subscribe key”. I would like all keys and customer data to be isolated from one another.
You should use the PAM access manager feature for handling this. In addition to the subscribe key you will also provide your customers an auth-token. You can grant access to an auth-token to publish/subscribe to a specific set of channels.
You can find more details here:
http://www.pubnub.com/docs/javascript/tutorial/access-manager.html
I recently migrated an old push notification app to a new Azure Mobile Service. The MPNS API, apparently, has changed. It also automatically created a notification hub. Now instead of being able to define a clear channel URI for the message to be sent to, I need to specify a tag. I find it very hard to find information on this and how to send messages to individual users from Azure Mobile Services.
How is this done now?
Its actually pretty simple. Use your unique user identifier as a tag when you register.
Here is an example.
Registration reg = new AppleRegistration(token)
reg.getTags().add(userId)
hub.createRegistration(reg)
Now when you want to send to that user, send via the tag.
hub.sendNotification(Notification.createAppleNotification(payload), userId)
With Notification Hubs you have a few different options. Tags are the way of identifying who you want to push to (i.e. when you push to tag X, any device that has registered with tag X will be pushed to). So if you want to push based off of channel URI, when you register from the device, you should use the Channel URI as one of the tags. If you want to be able to push to all of a single user's devices, you'd need a different mechanism of knowing who the user is (i.e. registering with the username as a tag and then pushing to the username).
I would like to use Azure Notification Hubs to send push notifications to users of my app running across iOS, Android and Windows Phone.
I have managed to get the basics working but I don't know how to manage the App uninstall story.
On starting, the mobile app will call my Identity Svc to get an Auth Token.
It then calls its Platform Notification service (eg Google Cloud Messaging, APNS) to get a PNS Token.
After persisting the token to local storage it will call a back-end Contact Svc to register the customer's device. This service will create a subscription to the Azure Notification hub for the device.
This is illustrated in the following diagram:
Later on a back-end publishing service will call the Contact Service requesting a push notification for a particular user id. The contact service will lookup the Id allocated to a tag on the notification hub and send a push request.
What options are available to determine when a customer uninstalls the app? Is it just a matter of trapping errors when calling "Send" on the notification hub? I guess this could work if only sending to a single user but my intention is that certain message types are to be published to multiple subscribers. On the initial registration of a device a subscription will be created for a tag of the user id but also for a more general tag such as "New Promotion". The publishing service would later want to issue a "New Promotion" notification to all devices.
Why do you need to know app uninstalls?
Notification Hubs automatically expire registrations for devices that get uninstalled.
Also, I would avoid persisting the PNSHandles in your service at all.
The current guidelines for using hubs are the following:
store the registrationIds of the registrations associated with the device in local storage. This enables you to update tags and channel information with a single update call.
Because mobile connections are not always reliable, it is best to avoid creating a new registration without being able to store the registrationId in local storage. This can result in the device registering multiple times, causing duplicate notifications. You can achieve this by using the Create Registration ID and Create or Update Registration REST APIs.
The first API returns a registrationId without actually creating a registration. When the ID has been securely stored on the device storage, the device can call the Create or Update Registration API.
So I would have your ContactSvc expose two functionalities:
a) create registration id (just call hub to get it)
b) create or update registration given (registrationId, pnsHandle, tags?)
Then your device keeps the regId in its storage, ad after getting the handle from PNS, if as regId is not there creates a new one with endpoint a), then updates the registration with pnsHandle and tags.
Note that in this way your service does not need to persist handles or UUIDs, and does not need to worry about app uninstalls.
If you are keeping track of users, one approach is to periodically (once a month?) check in your hub if its registrations are still there...
You can reach me at #eliodamaggio if this is not clear.
I am evaluating which Push Notification service to use out of Azure Mobile Services, Parse and Urban Airship.
One of the criteria is whether the service provides a way for the app to register a bespoke user Id or alias that can then easily be used when calling the service to send a push notification to an individual. This removes the need for our backend service to have a lookup table giving us the service registration ID for a given user.
Urban Airship has the alias feature: http://docs.urbanairship.com/connect/connect_audience.html#aliases
Parse has a sophisticated Installation object which behaves like a dictionary so that additional values can be added to it (like UserId). When the Parse service is called to send a Push Notification a query can be used to specify the user that will receive the message:
https://www.parse.com/docs/push_guide#sending-queries/REST
Is there an equivalent feature in Azure Mobile Services?
With Mobile Services, you would need to keep track of a user to token / channel URI / registration ID association in a table which is more work than you NEED to do. However, another feature of Windows Azure is Notification Hubs which does what you want (and much more). With Notification Hubs, from the client you say "I want to register for Notification Hubs, here are some tags you can use to push me information". Those tags can be anything you want including a User ID. Later on you can tell your Notification Hub to push to anyone registered with a certain tag. That would allow you to then push notifications out to any devices a specific user has registered.
The flow would look something like this:
Register with Push Provider (APNS, GCM, MPNS, WNS)
Send token to Notification Hubs along with tags (such as the User's ID)
Trigger a push to a specific Tag (i.e. User ID)
Notification Hubs will handle delivering a push to all devices with a Tag (again, their user ID)
Notification Hubs has client SDKs for WinPhone, WinStore, iOS, and Android so it's very easy to use from the client side. As far as triggering pushes goes, Notification Hubs exposes a REST API you can communicate with, there is a .NET SDK, a Node SDK, as well as an unofficial Java SDK. You can even use the Node SDK from Mobile Services which makes it super easy to combine authentication (i.e. getting User IDs) with data storage and push notifications. It also has lots of other features like templated push notifications so instead of specifying a different payload depending on what the device OS you're pushing to is, you can have the client application indicate how it should receive a certain type of push.