How can I access signalr hub via browser? I've created hub named "testhub" (using HubName property) and method "Hello" in it, so I want to access it smth like that: http://serverurl/signalr/testhub/Hello
SignalR is a real-time messaging framework and so a connection is first established using one of several higher level protocols over HTTP (WebSockets at best, long polling at worst) and then the Hub methods themselves are invoked by passing JSON formatted messages through that higher level protocol.
The example you're describing seems like you're expecting a request/response model and for that you are better off using a REST based technology like ASP.NET MVC or ASP.NET Web API.
Related
I currently have a mobile application talks to a GraphQL API service which terminates SSL and then proxies requests to gRPC services. The gRPC services only talk to each other via gRPC.
This system works okay but writing all of the boilerplate to plumb the gRPC APIs through the GraphQL layer to the client is tedious and can be error prone.
I’ve started exploring the idea of talking directly to the backend via gRPC as the tooling has improved substantially over the last few years.
One issue I’m still wondering about, though, is the best way to disambiguate APIs only meant to be called internally by other services from those callable publicly by the native client.
There is also a third category, “hybrid” APIs where it can be called either internally or externally.
Examples —-
Internal: Sending an SMS via Twilio
Public: Log in to account
Hybrid: Update whether an inbox item is read (both from the app when opening a conversation and on the backend when a message is sent)
One option I thought of was an interceptor that passes along a context to indicate if the request is internal or public and use this in the code to return an error or perform additional validation on public requests.
Another option is creating an API service which is still gRPC but fulfills the same purpose as the GraphQL API service.
A third option is disambiguating public and internal services at an organizational level which might require duplicating some APIs that exist for both.
Are there other options I’m unaware of? How have you tackled this issue?
I'm working on a PoC of a system where a mobile app client needs to be connected on a server with communications going both ways : either for updating the server or being updated by it. There is no client-to-client communications for the moment.
The client logs in the server via an HTTPS/POST method and gets back a token if the credentials are OK. This token is to be used by any further communication in order to authenticate the user. The reason why I'm using HTTPS for logging in is that there also is a web interface for other purposes.
I could not find a tutorial or documentation that explains how to implement this use case with channels based on websocket transport. All I found so far are either partial and focus on some specific aspects (eg authentication, setting SSL/TLS, etc) and assume the reader already knows the rest or are the over simplified implementations of the chat app. I'm sure I'm not looking at the right place...
My questions are:
What would be the list of callback to implement this use case on
either side
On the server: how does a process send notifications to the
client
NB: I'm using Elixir 1.5.1 and Phoenix 1.3
From the Phoenix guide:
Each Channel will implement one or more clauses of each of these four callback functions — join/3, terminate/2, handle_in/3, and handle_out/3.
The page I linked contains also an MCVE of sockets running on Phoenix. In the bottom there are examples of how the server-client communication is done.
The only thing to apply this to your use-case would be to use one of authentication libraries (e.g. Überauth that comes with great examples) to handle token on each subsequent connection request.
I am working on a project which is basically a Customer Feedback Analysis Dashboard. There are few graphs on the dashboard and data for each graph is fetched from the server through API requests.
Right now the dashboard is updated every time the page is refreshed. I want it to be updated immediately when there is a new feedback in the system. I am confused, whether I use websockets to send data for each graph or just a flag and use that flag to fetch data through API requests.
Like, facebook/twitter does. They tell you about new posts/tweets and when you click that button your feed/wall gets updated.
If you want to "push" data from server to client and you want that data to show up in a timely fashion (e.g. within 10-20 seconds of when it was available on the server), then you will want to implement some sort of "push" solution where the server can efficiently push data to the client whenever there is new data to send.
There are several possible approaches:
webSockets
socket.io
Server-sent events
Mobile platform-specific push (Android and iOS)
For a general purpose solution that works within a browser, you will want to use one of the first three. socket.io is built on top of webSockets (it just adds more features) so architecturally, they are similar.
Server-sent events are fairly new (modern browsers only) and are only for one way communication (from server to client). webSockets can be used for communication either way.
I'd personally recommend socket.io because of the features it offers (such as automatic client reconnection) and a simplified messaging layer. You can see the feature difference between socket.io and webSockets here. With socket.io, the client makes a connection to the server when the web page is loaded and that connection is persistent. After the connection is established, then either client or server can send messages to the other at any time in a very efficient manner.
Other useful references:
Push notification | is websocket mandatory?
websocket vs rest API for real time data?
Why to use websocket and what is the advantage of using it?
What are the pitfalls of using Websockets in place of RESTful HTTP?
Ajax vs Socket.io
I am query for a long time now.Where exactly we need to use WEB API and where should we use WCF restful services. What ever we want to achieve in WEB API we are able to achieve in WCF Rest. I tried to dig into answers but i got we need to do extra setting in wcf like URI templates,Contracts,endpoints. But its more on settings , but I wanted to known the real reason behind using WCF Restful Services.
Web Service
It is based on SOAP and returns data in XML format.
It supports only the HTTP protocol.
It is not open source but can be consumed by any client that understands XML.
It can be hosted only on IIS.
WCF
It is also based on SOAP and returns data in XML format.
It is the evolution of web services (ASMX) and support various protocols like TCP, HTTP, HTTPS, Named Pipes, MSMQ.
The main issue with WCF is its tedious and extensive configuration.
It is not open source but can be consumed by any client that understands XML.
It can be hosted with in the application or on IIS or using window service.
WCF REST
To use WCF as a WCF REST service you have to enable webHttpBindings.
It supports HTTP GET and POST verbs by [WebGet] and [WebInvoke] attributes respectively.
To enable other HTTP verbs you have to do some configuration in IIS to accept request of that particular verb on .svc files.
Passing data through parameters using a WebGet needs configuration. The UriTemplate must be specified.
It supports XML, JSON and ATOM data format.
Web API
This is the new framework for building HTTP services the easy and simple way.
Web API is open source an ideal platform for building RESTful services using the .NET Framework.
Unlike a WCF REST service, it use the full features of HTTP (like URIs, request/response headers, caching, versioning, various content formats).
It also supports the MVC features such as routing, controllers, action results, filter, model binders, IOC container or dependency injection, unit testing that makes it more simple and robust.
It can be hosted within the application or on IIS.
It is a light weight architecture and good for devices which have limited bandwidth like smart phones.
Responses are formatted by Web API’s MediaTypeFormatter into JSON, XML or whatever format you want to add as a MediaTypeFormatter.
Choosing between WCF or Web API
Choose WCF when you want to create a service that should support special scenarios such as one way messaging, message queues, duplex communication etc.
Choose WCF when you want to create a service that can use fast transport channels when available, such as TCP, Named Pipes, or maybe even UDP (in WCF 4.5), and you also want to support HTTP when all other transport channels are unavailable.
Choose Web API when you want to create a resource-oriented services over HTTP that can use the full features of HTTP (like URIs, request/response headers, caching, versioning, various content formats).
Choose Web API when you want to expose your service to a broad range of clients including browsers, mobiles, iPhone and tablets.
For more details you can refer to http://www.c-sharpcorner.com/UploadFile/8a67c0/who-is-winner-web-api-or-wcf/.
I have been reading articles about asynchronous messaging between clients using MVC3 and the SignalR library (http://sergiotapia.com/2011/09/signalr-with-mvc3-chat-app-build-asynchronous-real-time-persistant-connection-websites/)
We currently use activemq for some of our fat client apps and use topics to broadcast data to everyone. Does anyone know if this sort of thing could be used in MVC3 as well?
I'd like to create an application that doesn't require a user to install anything (and could even be used on a phone), but it would be monitoring continuously-changing data. We're talking refreshing data every 2-3 seconds.
If you want to have asynchronous messaging with client (browser) use SignalR. ActiveMQ and MSMQ are technologies for thick clients and server-to-server communication. They require installation (MSMQ requires windows installation) and they are not accessible from browser (well I can imagine accessing MSMQ through ActiveX or ActiveMQ from Java applet but that is not what you are looking for).
One of the possible ways to go is to build a web service which will implement communication with AMQ/MSMQ via their APIs and do poll this web service from your webpage (via ajax call for example) to refresh the data as it's needed.