We have developed an ASP Net MVC application using the Repository pattern.
We are creating a db context instance by using a context provider class like:
public class ContextProvider
public static DBEntities GetContext()
{
return HttpContext.Current.Items["_EntityContext"] as DBEntities;
}
}
Here we are making sure that the DBEntities db call exists only during the existence of the request - we are putting an instance into a Session map - HttpContext.Current.Items["_EntityContext"] in this example.
We are using this in our entire Asp Net Mvc Project as following:
public class TeamRepository
{
#region Members
private DBEntities storeDB = null;
#endregion Members
#region Constructors
public TeamRepository()
{
storeDB = ContextProvider.GetContext();
}
#endregion Constructors
#region Methods
...
Now we need to create a WCF service to enable access to some features to other vendors.
Since all the Repository classes are a part of a project - they were not excluded to a separated DLL I made a reference to the entire project in my new WCF project so that I could use already existing DB Repository method calls.
Here I am facing an issue since I am not able to access to the Session variable HttpContext.Current.Items["_EntityContext"] - method call public static DBEntities GetContext() is always returning null when called from WCF Service.
I tried to make HttpContext.Current Available Within a WCF Service available by placing
[ServiceBehavior(AddressFilterMode=AddressFilterMode.Any)]
[AspNetCompatibilityRequirements(RequirementsMode= AspNetCompatibilityRequirementsMode.Required)]
on my Service class,
and tweaking the serviceHostingEnvironment section of web.config, which now looks like this:
<serviceHostingEnvironment aspNetCompatibilityEnabled="true">
<baseAddressPrefixFilters>
<add prefix="http://localhost” />
</baseAddressPrefixFilters>
</serviceHostingEnvironment>
but with no results.
I am using Windows 10.
Do you know a way I can access HttpContext.Current.Items["_EntityContext"]... contained within Asp Net Mvc project from my WCF Project?
Regards
The issue is resolved using the following steps:
I decorated my service implementation with the AspNetCompatibilityRequirements attribute:
[AspNetCompatibilityRequirements(RequirementsMode= AspNetCompatibilityRequirementsMode.Required)]
public class Service : IService {
. . .
}
The last thing I had to do was necessitated by WCF not supporting multiple host headers; I had to hard-wire the WCF endpoint to listen on a specific hostname. In this case, this involved tweaking the serviceHostingEnvironment section of web.config, which now looks like this:
<serviceHostingEnvironment aspNetCompatibilityEnabled="true">
<baseAddressPrefixFilters>
<add prefix=http://services.mydomain.com” />
</baseAddressPrefixFilters>
</serviceHostingEnvironment>
And then adding another attribute to the service implementation class and initializing the HttpContext.Current.Items session:
[ServiceBehavior(AddressFilterMode=AddressFilterMode.Any)]
[AspNetCompatibilityRequirements(RequirementsMode= AspNetCompatibilityRequirementsMode.Required)]
public class Service : IService {
HttpContext.Current.Items["_EntityContext"] = new DBEntities();
...
}
Related
I am kind of new in implementing and using WCF services and extremely new (and apparently clueless) in DI.
I have WCF Services which are having constructors. The parameters of the constructors could only come in runtime from the Client application (Web server).
Something like this:
In Application server:
public class MyService : IMyService {
private IUserContext userContext;
public MyService(IUserContext uContext) {
this.userContext = uContext;
}
public DoWork() {
... // uses uContext
}
}
In Web server can only see IMyService and not the implementation of the MyService. The code would be something like this (oversimplified console app):
class Program {
static void Main(string[] args) {
var factory = new ChannelFactory<IMyService>("MyServiceEndpoint"); // MyServiceEndpoint correctly defined in config file
var client = factory.CreateChannel();
client.DoWork();
((IClientChannel)client).Close();
factory.Close();
}
}
First WCF "forced" me to use parameter-less constructor in the implementation of MyService in order to test it I added that by initializing the UserContext object. Of course I don't have the necessary info to create the object in compile time so this won't help me.
I proceeded with using this solution creating my own ServiceHostFactory, ServiceHost and IInstanceProvider where IDependency is an interface IUserContext which is implemeted by my UserContext class.
This works as expected, I registered in my svc file the custom factory, I don't need parameter-less constructor anymore. However since I don't know how to pass my UserContext to the InstanceProvider I only get a default UserContext object.
Now my noviceness comes in. I don't know how to invoke MyService by passing in the UserContext which lives in the web server. Do I also need own ChannelFactory?
Can someone direct me in the right way by updating the web server dummy code?
Thanks!
Remark: I don't want UserContext to be a parameter of the DoWork() method, because that would mean changing the parameter list of all my services and all calls...
The notion of constructors does not exist on the wire (no matter what transport you are using). For that reason you will never be able to make the client invoke a particular constructor. This is simply not part of the design of WCF (also not part of SOAP).
Don't use constructor parameters that are provided by the client. Or, make the service class have a parameterless ctor and make all service methods accepts the former constructor parameters as normal parameters.
You can also transmit common parameters as SOAP headers. That saves you changing the signature of all service methods.
We are implementing ntier architecture for one of the project which uses EF6 ORM. DbContext scope is managed by ContextStoreFactory. Based on configuration ContextStoreFactory uses HttpContextStore/StaticContextStore to create DbContext. For console app its working fine. Now we planning for implemnting a wcf service with net.msmq binding which uses underneath services to process incoming request.
public class TestService : ITestService
{
public void ProcessPerson(Person person)
{
var repo = GetRepository();
var personService = new PersonService(repo);
personService.Process(person);
}
private IRepository GetRepository()
{
var context = ContextStoreFactory.GetContextStore().GetContext();//Calls OperationcontextStore
return new Repository(context);
}
}
I would like to manage the DbContext scope in wcf service. I come across many articles which says its best to use DBContext per call/operation. My sample OperationContextStore looks like follows. Please feel free to correct if it requires any correction.
public class OperationContextStore
{
public static readonly string ITEM_NAME = "DBCONTEXT-INSTANCES";
public DBContext GetContext()
{
if(!OperationContext.Current.OutgoingMessageProperties.ContainsKey(ITEM_NAME))
OperationContext.Current.OutgoingMessageProperties.Add(ITEM_NAME, new DBContext());
return (DBContext)OperationContext.Current.OutgoingMessageProperties[ITEM_NAME];
}
public void Dispose()
{}
}
I would like to know Is DbContext scope per call is valid in my scenario?
Is the approach to create Repository in my service method is valid?
Are there any best practices to wire this up without using IOC?
I know it's late to answer my own question and I will try to recollect what I did
I would like to know Is DbContext scope per call is valid in my scenario?
Yes,It was valid in my scenario.
Is the approach to create Repository in my service method is valid?
I ended up having IRepository as a property in my service class and did a property injection.
Are there any best practices to wire this up without using IOC?
I ended up writing my own utility. Please search for poor man's dependency injection.
I've created an WebService proxy class based on a WSDL (in my Visual Studio 2010 .NET solution).
Now what I need is, that the soap header of my request to the remote web service have a specific format, imagine something with two or three fields is not very relevant.
So my solution was, I edited the code generated by Visual Studio and commented out the method where i needed that custom soap header.
Next, because the web service class is marked as partial, I created safe code (that cannot be touched by the generator) in a class with the same name of the generated one (so it's the same class) and declared there the method commented out previously.
I declared it like this:
//this is the generated code file
public partial class Invoices: InvoicesWS.invoices
{
//[System.Web.Services.Protocols.SoapDocumentMethodAttribute( ...
//public RegisterInvoiceResponseType RegisterInvoice(RegisterInvoiceType ...)
//{ ... }
}
//this is the class I created else where in my project
public partial class Invoices: InvoicesWS.invoices
{
public SecureSoapHeader Security { get; set; }
[SoapHeader("Security", Direction = SoapHeaderDirection.In)]
[System.Web.Services.Protocols.SoapDocumentMethodAttribute(
"http://someurl.pt/invoices/RegisterInvoice",
Use = System.Web.Services.Description.SoapBindingUse.Literal,
ParameterStyle = System.Web.Services.Protocols.SoapParameterStyle.Bare),
TraceExtension()]
public RegisterInvoiceResponseType RegisterInvoice(RegisterInvoiceType RegisterInvoiceElem)
{
object[] results =
this.Invoke("RegisterInvoice", new object[] {RegisterInvoiceElem});
return ((RegisterInvoiceResponseType)(results[0]));
}
}
So, to make my proxy class send a custom header I did this.
But every time I remember to update the web reference, I'll have to manually comment out the method above that is being generated by the Visual Studio tool, to avoid conflicts due to having to methods
with the same signature.
Is there a better way, or best practice to address this situation?
Please do not advise me to do it with WCF, I know the solution for that,
but correctly this is the code that has been working and changing it at
this time is not a possibility.
Thanks.
You can achieve it with SoapExtension. You can create class that implements SoapExtension, and register it in web.config.
Sample of soap extension:
public class SecureSoapExtension : SoapExtension
{
public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
{
return null;
}
public override object GetInitializer(Type serviceType)
{
return null;
}
public override void Initialize(object initializer)
{
}
public override void ProcessMessage(SoapMessage message)
{
// just for out requests
if (message.Stage == SoapMessageStage.BeforeSerialize)
{
// add needed soap header here
message.Headers.Add(new SecureSoapHeader());
}
}
}
And register in web.config to apply to all web services:
<system.web>
<webServices>
<soapExtensionTypes>
<add type="MyTestMvcApplication.SecureSoapExtension, MyTestMvcApplication, Version=1.0.0.0, Culture=neutral"></add>
</soapExtensionTypes>
</webServices>
</system.web>
Important note: If you are calling your Web Service from an external project, let's say, you have a Class Library where you program all your Proxy handling logic. You must add this to your calling project web.config/app.config too, otherwise it will not work:
<system.web>
<webServices>
<soapExtensionTypes>
<add type="MyTestMvcApplication.SecureSoapExtension, MyTestMvcApplication, Version=1.0.0.0, Culture=neutral"></add>
</soapExtensionTypes>
</webServices>
</system.web>
What kind of makes sense, since it's an Web Service extension it's let up to you "final caller" of the proxy, to decide whether to extend or not the web service request.
I am using C# Visual Studio 2012 to create a wcf service.
I had the WSCF.blue tool generate the wsdl from the xsd-s. Then I generated the web service code using the same tool. WSCF.blue does not create a Service Contract and a Data Contract. It creates an interface and a .svc file that contains a class that implements the interface.
When generating the web service code I selected the option to create the abstract classes because I want to be able to keep the implementation of these classes in a separate file.
The abstract class looks like this:
[KnownType(typeof(WebMobileImplementation))]
public abstract class WebMobile : IWebMobile
{
public abstract PutLocationsResponse PutLocations(PutLocationsRequest request);
}
The implementing class (in a different file) looks like this (for now):
public class WebMobileImplementation : WebMobile
{
public override PutLocationsResponse PutLocations(PutLocationsRequest request)
{
PutLocationsResponse response = new PutLocationsResponse();
return response;
}
}
When trying to browse the service I get the message: "Service implementation type is an interface or abstract class and no implementation object was provided"
I thought that adding the knowntype to the implementing class will do the trick but it seems that the implementation is not 'seen' when running the service. What else can I do to 'connect' them?
In WCF 4.0, you can define virtual service activation endpoints that map to your service types in Web.config. This makes it possible to activate WCF services without having to maintain physical .svc files.
<serviceHostingEnvironment>
<serviceActivations>
<add relativeAddress="WebMobile.svc"
service="WebMobileNamespace.WebMobileImplementation"/>
</serviceActivations>
</serviceHostingEnvironment>
I have a web application that accesses a database through a wcf service. The idea is to abstract the data from the web application using the wcf service. All that works fine but I am also using the built in roleprovider using the SqlRoleManager which does access the aspnetdb database directly. I would like to abstract the roleprovider by creating a custom roleprovider in a wcf service and then accessing it through the wcf service.
I have created the custom role provider and it works fine but now I need to place it in a wcf service.
So before I jump headlong into trying to get this to work through the WCF service, I created a second class in the web application that accessed the roleprovider class and changed my web config roleprovider parameters to use that class. So my roleprovider class is called, "UcfCstRoleProvider" and my web.config looks like this:
<roleManager
enabled="true"
defaultProvider="UcfCstRoleProvider">
<providers>
<add
name="UcfCstRoleProvider"
type="Ucf.Security.Wcf.WebTests.UcfCstRoleProvider, Ucf.Security.Wcf.WebTests"
connectionStringName="SqlRoleManagerConnection"
applicationName="SMTP" />
</providers>
</roleManager>
My class starts like this:
public class UcfCstRoleProvider : RoleProvider
{
private readonly WindowsTokenRoleProvider _roleProxy = new WindowsTokenRoleProvider();
public override string ApplicationName
{
get
{
return _roleProxy.ApplicationName;
}
set
{
_roleProxy.ApplicationName = value;
}
}
As I said, this works fine. So the second class is called BlRoleProvider that has identical properties and parameters as the roleprovide but does not implement RoleProvider. I changed the web.config to point to this class like this:
<roleManager
enabled="true"
defaultProvider="BlRoleProvider">
<providers>
<add
name="UcfCstRoleProvider"
type="Ucf.Security.Wcf.WebTests.BlRoleProvider, Ucf.Security.Wcf.WebTests"
connectionStringName="SqlRoleManagerConnection"
applicationName="SMTP" />
</providers>
</roleManager>
But I get this error.
"Provider must implement the class 'System.Web.Security.RoleProvider'."
I hope I have explained well enough to show what I am trying to do. If I can get the roleprovider to work through another class in the same application, I am sure it will work through the WCF service but how do I get past this error?
Or maybe I took a wrong turn and there is a better way to do what I want to do??
I think your best bet is to create a custom role provider and implement each method. In the implementation of each method, call the WCF service to do the data access. Eg:
public class WcfRoleProvider: RoleProvider
{
public bool IsUserInRole(string username, roleName)
{
bool result = false;
using(WcfRoleService roleService = new WcfRoleService())
{
result = roleService.IsUserInRole(username, roleName);
}
return result;
}
}
No, you have to have a class that must implement RoleProvider. That will not work. If you can't have this class inherit from RoleProvider directly, consider creating a RoleProvider wrapper class that implements RoleProvider's props/methods, but utilizes whatever you need to do with this second class.
This error isn't specific to WCF, but is specific to the role provider framework.
HTH.
Looking at your code it appears that you already have your configuration using a custom role provider.
If you want to be able to authentiacate users mking calls through your web service you should implement a custom header that authenticates each request against your configured role provider.
Things work slightly differently in WCF, it's not like you have access to session and application states since each call is considered to be a stateless one, a custom header however will offset that by handling this stuff as the call is made.