Can I interact with .NET libraries through Javascript? - c#

We've built a set of .NET libraries (in C#) which are used to interact with an outside resource. The outside resource provide bindings in Java and .NET, so it was necessary to build our libraries in one of those languages and we're officially a Windows shop.
We also use PHP/Javascript for a lot of our front-end web applications. Is it possible for these PHP/Javascript web applications to interact with our .NET libraries? We have both IIS and Apache web servers if that makes a difference. Communication would need to go in both directions.

The most obvious approach is exposing your .NET libraries as web services on a web server (either IIS or Apache/Mono). This allows both JS and PHP to consume the same service endpoints (JS via AJAX, PHP vs web service calls).
If extreme performance is a concern - for example, your PHP apps need to make heavy calls into the .NET libraries as if they are native, then web services are probably not the best approach. For that, you might want to look into making COM Callable Wrappers for your .NET libraries and consuming them from PHP.

Although Ajax is the usual approach, another idea for you, in case it might help, would be to use Silverlight on the client side. That way, you would embed your .NET classes into a Silverlight application, which would then be downloaded to the client where it would run inside the browser. Silverlight apps can easily interact bi-directionaly with JavaScript, as well as with remote resources.
For example, you can mark a .NET method with the [ScriptableMember] attribute, which will expose it to JavaScript.

You can pass data via AJAX calls where you communicate to and from the client via JSON. For client side data set manipulation jLinq is a great library for performing Linq queries on JSON objects.
If you are looking for a good place to start with web services, JSON and ASP.Net webforms Dave Ward's posts on Encosia are really top notch.

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WCF or Web API for windows form application [duplicate]

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I've spent a few months trying to grasp the concepts behind WCF and recently I've developed my first WCF service application.
I've struggled quite a bit to understand all the settings in the config file.
I am not convinced about the environment but it seems that you can do amazing stuff with it.
The other day I've found out that Microsoft has come out with a new thing called ASP.NET Web API.
For what I can read it's a RESTful framework, very easy to use and implement.
Now, I am trying to figure out what are the main differences between the 2 frameworks and if I should try and convert my old WCF service application with the new API.
Could someone, please, help me to understand the differences and usage of each?
For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:
The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).
WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.
ASP.net Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know ASP.net MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the ASP.net MVC.
Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.
In the scenarios listed below you should go for WCF:
If you need to send data on protocols like TCP, MSMQ or MIME
If the consuming client just knows how to consume SOAP messages
WEB API is a framework for developing RESTful/HTTP services.
There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.
HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.
Since using both till now, I have found many differences between WCF and Web API. Both technology stacks are suited well to different scenarios, so it is not possible to say which is better, this depends on configuration and scenario.
Properties ASP.Net Web API WCF
--------------------------------------------------------------------------------------------------
End point (mainly) Http based SOAP based
Service Type Front End Back-end
Support caching, compression, versioning No
Framework ASP.net WCF
Orientation Resource Oriented Service Oriented
Transports http http, tcp, MSMQ, Named pipe
Message pattern Request reply request Reply, one way, duplex
Configuration overhead Less Much
Security lesser than WCF (web standard security) Very high (WS-I standard)
Hosting IIS IIS, Windows Service, Self hosting
Performance Fast A bit slower than Web API
In use from .NET 4.0 .NET 3.5
Note: The data is not only my view, it is also collected from other official websites.
WCF will give you so much of out the box, it's not even comparable to anything. Unless you want to do on your own implementation of (to name a few) authentication, authorization, encryption, queuing, throttling, reliable messaging, logging, sessions and so on. WCF is not [only] web services; WCF is a development platform for SOA.
Why I'm answering:
I took huge amount of time to understand the difference between these two technologies. I'll put all those points here that I think "If I had these points at the time when I was wondering around in search of this answer, then I have decided very earlier in selecting my required technology."
Source of Information:
Microsoft® Visual Studio® 2015 Unleashed
ISBN-13: 978-0-672-33736-9 ISBN-10: 0-672-33736-3
Why ASP.NET Web API and WCF:
Before comparing the technologies of ASP.NET Web API and WCF, it is important to understand there are actually two styles/standards for creating web services: REST (Representational State Transfer) and SOAP/WSDL. The SOAP/WSDL was the original standard on which web services were built. However, it was difficult to use and had bulky message formats (like XML) that degraded performance. REST-based services quickly became the alternative. They are easier to write because they leverage the basic constructs of HTTP (GET, POST, PUT, DELETE) and typically use smaller message formats (like JSON). As a result, REST-based HTTP services are now the standard for writing services that strictly target the Web.
Let's define purpose of ASP.NET Web API
ASP.NET Web API is Microsoft’s technology for developing REST-based HTTP web services. (It long ago replaced Microsoft’s ASMX, which was based on SOAP/WSDL.) The Web API makes it easy to write robust services based on HTTP protocols that all browsers and native devices understand. This enables you to create services to support your application and call them from other web applications, tablets, mobile phones, PCs, and gaming consoles. The majority of applications written today to leverage the ever present Web connection use HTTP services in some way.
Let's now define purpose of WCF:
Communicating across the Internet is not always the most efficient means. For example, if both the client and the service exist on the same technology (or even the same machine), they can often negotiate a more efficient means to communicate (such as TCP/IP). Service developers found themselves making the same choices they were trying to avoid. They now would have to choose between creating efficient internal services and being able to have the broad access found over the Internet. And, if they had to support both, they might have to create multiple versions of their service or at least separate proxies for accessing their service. This is the problem Microsoft solved with WCF.
With WCF, you can create your service without concern for boundaries. You can then let WCF worry about running your service in the most efficient way, depending on the calling client. To manage this task, WCF uses the concept of endpoints. Your service might have multiple endpoints (configured at design time or after deployment). Each endpoint indicates how the service might support a calling client: over the Web, via remoting, through Microsoft Message Queuing (MSMQ), and more. WCF enables you to focus on creating your service functionality. It worries about how to most efficiently speak with calling clients. In this way, a single WCF service can efficiently support many different client types.
Example of WCF:
Consider the example:
The customer data is shared among the applications. Each application might be written on a different platform, and it might exist in a different location. You can extract the customer interface into a WCF service that provides common access to shared customer data. This centralizes the data, reduces duplication, eliminates synchronization, and simplifies management. In addition, by using WCF, you can configure the service endpoints to work in the way that makes sense to the calling client. Figure shows the example from before with centralized access of customer data in a WCF service.
Conclusion:
i) When to choose Web API:
There is no denying that REST-based HTTP services like those created using ASP.NET Web API have become the standard for building web services. These services offer an easy, straightforward approach for web developers building services. Web developers understand HTTP GET and POST and thus adapt well to these types of services. Therefore, if you are writing services strictly targeted to HTTP, ASP.NET Web API is the logical choice.
ii) When to choose WCF:
The WCF technology is useful when you need to support multiple service endpoints based on different protocols and message formats. Products like Microsoft BizTalk leverage WCF for creating robust services that can be used over the Web as well via different machine-to-machine configurations.If, however, you do need to write an application that communicates over TCP/IP when connected to the local network and works over HTTP when outside the network, WCF is your answer.
Be Warned:
Web developers often view WCF as more difficult and complex to develop against. Therefore, if you do not foresee the need for multiprotocol services, you would likely stick with ASP.NET Web API.
There is a comparison on MSDN about this
WCF and ASP.NET Web API
For me, the choice was about Who the clients are, and where are they located?
Within the company Network and .NET based clients : Use WCF with TCP binding (Fast communication than HTTP)
Outside the company Network, and use diverse technologies like PHP, Python etc: Use Web API with REST
Business speaking, WebApi lacks of a WSDL, so the developers should document all manually. And if, for example, the WebApi operation returns a list of objects then, the client should creates the objects manually, i.e. WebAPI is really prone to errors of definitions.
The pro of Webapi is its more lightweight than WCF.
Regarding the statement "WebApi lacks of WSDL" there are several ways to generate Rest client. One popular approach is Swagger UI / (Swashbukkle Nuget). This gives a rich interface to understand the REST end point's input and output schema and online tool to test the end points.
JSON LD (Json Linked Documents) is another emerging standard which will further improve the JSON based REST developer experience by exposing the JSON schema with better semantics.
With wcf we can configure and expose the same service support for multiple endpoints like tcp, http.if you want your service to be only http based then it will be better to go with web API. Web API has very less configuration when compared to wcf and is bit faster than wcf. Wcf also supports restful services. If you have limitation of .Net framework 3.5 then your option is wcf.

Interaction between web and a C# .dll

I have to call a method of a complex .dll C# library when I get a "request".
Since I don't want to program the network part (socket, protocol, etc.), I'm thinking of using an existing Web server (IIS or Apache) to handle this part (and use HTTP as protocol).
Is it possible to load the .dll in memory and call a method of it from a web server? How to do it?
If yes, is it better to use IIS on Windows, Apache or Windows, or Apache on Linux?
Is it mandatory to call this method of the C# .dll using C#/ASP? Or can it be with PHP?
It has to be very scalable, and the .dll library uses the .NET Framework.
Of course I'm thinking of exec function in PHP, but this would start a C# program again and again for each single request, which is not very good.
I would like to load the C# .dll once in memory, and have it running on the web server directly if possible, so that only "calls" to a method happen when I get a specific HTTP request.
My question has similarities to this one, however I don't believe our problems are the same.
Is it possible to load the .dll in memory and call a method of it from a web server? How to do it?
Yes, for example by programming a service layer around it using WCF or the ASP.NET Web API. Given the quirky (to say the least) interoperation of SOAP services and clients, I'd go with the latter.
You can then call your SOAP/REST/giveitaname service through PHP's cURL or any other applicable method, and your C# service will then call the code in the DLL (this part you'll have to build).
You can host both types of project easily in IIS, making it accessible through HTTP.

HTML5 web socket with ASP.NET

Is It possible to create HTML5 Web Socket by use of ASP.NET/Web Form?
Uhm. No. HTML5 web sockets are a client-side feature, meaning you can use it with JavaScript code through the WebSocket object. Thus, from the client-side code you write in your ASP.NET WebForms/MVC project, you are able to use it.
If you are trying to support the web socket protocol through ASP.NET, that is possible with a very new version of ASP.NET. Is this what you're trying to do? Your question is a bit vague.
The short answer is No, not with .NET 4.0 and IIS 7.5 (current production releases of .NET and IIS respectively). As J.P. mentions there will be support for web sockets in the future. More specifically, IIS 8 will be able to support this along with some additions to the System.Net namespace that will be bundled with ASP.NET 4.5.
In the mean time you may be interested interested in learning a bit more about SignalR. It includes a client side library that makes use of HTML5 Web Sockets, but falls back to long-polling if web sockets aren't supported by either the client or the server. And best of all, this fallback mechanism is transparent to the client and implementer. A .NET server implementation that supports web sockets is also provided.
This SO Q & A may also be of interest.
.NET 4.5 WebSockets vs SignalR
You should consider trying VisualJS.NET . Which is builtin reverse ajax and websocket supported asp.net web application development layer.

Creating a stateful client-server architecture in WCF

I am currently in the planning stages for a fairly comprehensive rewrite of one of our core (commercial) software offerings, and I am looking for a bit of advice.
Our current software is a business management package written in Winforms (originally in .NET 2.0, but has transitioned into 4.0 so far) that communicates directly with a SQL Server backend. There is also a very simple ASP.NET Webforms website that provides some basic functionality for users on the road. Each of our customers has to expose this site (and a couple of existing ASMX web services) to the world in order to make use of it, and we're beginning to outgrow this setup.
As we rewrite this package, we have decided that it would be best if we made the package more accessible from the outside, as well as providing our customers with the option of allowing us to host their data (we haven't decided on a provider) rather than requiring them to host SQL Server, SQL Server Reporting Services, and IIS on the premises.
Right now, our plan is to rewrite the existing Winforms application using WPF, as well as provide a much richer client experience over the web. Going forward, however, our customers have expressed an interest in using tablets, so we're going to need to support iOS and Android native applications as clients, as well.
The combination of our desire to offer off-site hosting (without having to use a VPN architecture) and support clients on platforms that are outside of the .NET ecosystem has led us to the conclusion that all of our client-server communication should take place through our own service rather than using the SQL Server client (since we don't want to expose that to the world and SQL Server drivers do not exist, to my knowledge, for some of those platforms).
Right now, our options as I see them are:
Write a completely custom service that uses TCP sockets and write everything (authentication, session management, serialization, etc.) from scratch. This is what I know the most about, but my assumption is that there's something better.
Use a WCF service for transport, and either take care of authentication and/or session management myself, or use something like durable services for session management
My basic question is this:
What would be the most appropriate choice of overall architecture, as well as specific features like ASP.NET authentication or Durable Services, to provide a stateful, persistent service to WPF, ASP.NET, iOS, and Android clients?
(I am working on the assumption that by "stateful" you mean session-based).
I guess one big question is: Do you want to use SOAP in your messaging stack?
You may be loathe to, as often there is no out-of-box support for SOAP on mobile platforms (see: How to call a web service with Android). No doubt its similarly painful with iOS. Calling SOAP from a browser ("ASP.NET") can't be fun. I'm not even sure its possible!
Unfortunately if you aren't using SOAP, then that quickly rules out most of WCFs standard Bindings. Of the one that remains, "Web HTTP", sessions are not supported because obviously HTTP is a stateless protocol. You can actually add session support by hand using a solution based on Cookies.
You could use the TCP transport (it supports sessions), and build you own channel stack to support a non-SOAP encoding (for example protocol-buffers), but even then you need to be careful because the TCP transport places special 'framing' bytes in it, so that would make interop non-trivial.
What sort of state do you need to store in your sessions? Maybe there are alternative approaches?
1) consider stateful utility services using singletons, but keep the request/response pattern at the facade level stateless.
2) consider distributed caching, perhaps Windows Server AppFabric Cache.

Looking for a Best Practice regarding Webservices between .Net and Cocoa

I'm planning a project which will consist of a Windows Server Application programmed in .Net/C# and Clients programmed in Silverlight/C#, Windows Forms/C# and a MacClient programmed in Cocoa. My Question is, which Webservice technology will be the best for the communication between the Clients and the Server and is the easiest to program in all of those technologies? I've no experience in Webservices and since Time is running short I hope to get some opinions of developers who worked in such a kind of heterogeneous project.
On the back end, you will definitely want to run Windows Communication Foundation, using the WSHttpBinding or the BasicHttpBinding depending on your needs.
This will make it easier to have Windows Forms and Silverlight clients.
Also, because using WCF with those bindings conforms to established standards, you should be able to access the services from almost any other environment - there should be tools that you can just point it to your metadata endpoint and it will generate proxies for you.
Another option is to use WCF to create a REST service (with JSON encoding most likely). WCF does help you a little bit here, but if this is the design you want to use, then you will want to look at ASP.NET MVC on the back end as well, as it makes creating these kind of services very, very easy.
However, when using REST services, there isn't a service description through something like WSDL, so you will have to generate the proxies to call your services by hand (at least, in environments outside of .NET).
The current technology used to develop web services on .NET is WCF. For interoperability with non .NET clients you should consider using basicHttpBinding endpoint. You could even expose multiple endpoints with different bindings, for example expose interoperable endpoint for non .NET clients and some fast binding for .NET clients. Here's a nice article on MSDN covering the performance of the different bindings. Given those keywords you might checkout the tutorials.

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