I have a C# Owin WebApi Selfhost Project and the controllers I use are implemented in separate assemblies.
I´m finding these assemblies by naming conventions before I start up the WebApp and load them into the AppDomain. Then when the Api starts, the controllers are accessible. There is another approach which involves a custom IAssemblyResolver-class which replaces the default one in the Config.Services
config.Services.Replace(typeof(IAssembliesResolver), new MyAssembliesResolver());
This also works, all my seperate controller-assemblies are found, loaded and accessible.
Now to the problem: It may occur, that a new controller-assembly appears in my executing directory. My Api has an "AssembliesController" which can be told to look for new assemblies in the executing directory and load them
during runtime. This also works, but the problem is: the controllers in the newly loaded assembly aren´t accessible until I restart my Api.
It appears that the Api just asks once for assemblies (IAssembliesResolver) and available controller types (IHttpControllerTypeResolver) on startup and works with the results until the end. But in my case I want to add assemblies/controllers during runtime without restarting the Api. Can somebody help me please? How do I get the Api to refresh the assemblies/controllers?
You need to overwrite the DefaultHttpControllerSelector.
Here is a very nice article on the subject: link
Enjoy!
Related
We have a legacy webforms app and a new section of our site developed with MVC. It works a treat as an application in the Default Web Site in IIS.
Only downside is that the root site's session object isn't passed to the application. We have a work around for this.
A consultant is convinced that we don't need to set it up as an application and it can all be done via handlers and route mappings. He conveniently has not provided us with any details though and I have been tasked to implement it.
The best I have achieved was to add a Module Mapping to the Handler Mapping section in IIS. This filters coolmvcapp/* with Module isapimodule to a virtual directory who's physical path points to our new MVC app. The result is an empty page with a 200 response. Most other combinations I have tried resulted in a variety of errors. (Turns out an empty page is returned without adding the handler mapping - hey ho)
So, is this approach even possible?
I am aware that MVC and webforms can be merged together but for reasons this is something that we want to avoid.
I have a project based on the Chris Hammond, Christoc, module template. I have a ton of code that I use to access data an external database. In my repositories I change the database from the default to whichever I need for that particular object. I do so with code that looks like this:
using (IDataContext ctx = DataContext.Instance(MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY))
{
var rep = ctx.GetRepository<Product>();
products = rep.Get().ToList();
}
The default database is switched in the call to .Instance(). The repositories are used by my custom DNN modules. The repository is part of the solution that contains multiple custom modules. When I compile and install using the Extensions part of DNN, everything works well. In the code above, MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY is found in a file MyModuleSettingsBase.cs file of my module solution. It is set to a simple string like "ProductDatabase". In the solution for the base DNN install (not the module solution), within the web.config file, there is a value in <connectionStrings> with name="ProductDatabase" which contains the actual connection string. This all links up fine on the DNN website.
Now I am writing a console application that does some monitoring of the site. I want to access the database to check values in the product table. I would like to reuse all of the repository code I have written. In an attempt to do so, I added a reference to the MyModules.dll file so I would only have one copy of the base code. This works to give me access to all the objects and the associated repositories but when I attempt to query data it fails. When debugging I can see that it fails on the line:
using (IDataContext ctx = DataContext.Instance(MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY))
When viewed in a debugger, the string value MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY is correctly set to "ProductDatabase" but the code is unable to link this with the actual connection string. I don't know where it would be checking for the connections string when running from my console application. I attempted to put a <connectionStrings> section into my App.config file but this didn't do the trick.
Is it possible to have MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY map to the connection string in an external application which references the DLL?
If so, where can I set the value of my connection string so it matches up to the key value stored in MyModuleSettingsBase.DATABASE_CONNECTION_STRING_KEY?
I was faced similar problem 3 months ago, at that time I want to use DNN core libraries in my console application but I was failed.
I placed my queries in DNN official forum website and I got a valid response from Wes Tatters (DNN MVP).
Here is the post link: Reference URL
As your requirement of monitoring, I suggest you to create DNN Schedule Application. You can schedule it within DNN (Host->AdvancedSettings->Schedule), even good point is that you can use your repositories (DNN Libraries) in that schedule application.
I hope it solved your problem. Let me know if you have any questions.
I used to place my controllers into a separate Class Library project in Mvc Web Api. I used to add the following line in my web api project's global.asax to look for controllers in the separate project:
ControllerBuilder.Current.DefaultNamespaces.Add("MyClassLibraryProject.Controllers");
I never had to do any other configuration, except for adding the above line. This has always worked fine for me.
However I am unable to use the above method to do the same in WebApi2. It just doesn't work. The WebApi2 project still tries to find the controllers in its own project's controllers folder.
-- Giving little summary update after 2 months (As I started bounty on this):
I have created a WebApiOne solution, it has 2 projects, the first one is WebApi project, and the second is a class library for controllers. If I add the reference to the controllers class library project into the WebApi project, all works as expected. i.e. if i go to http://mydevdomain.com/api/values i can see the correct output.
I have now create a second project called WebApiTwo, it has 2 projects, the first one is WebApi2 project, and the second is a class library for controllers. If I add the reference to the controllers class library project to the WebApi2 project, it doest NOT work as expected. i.e. if i go to http://mydevdomain.com/api/values i get "No type was found that matches the controller named 'values'."
for the first project i am not doing any custom settings at all, i do NOT have:
ControllerBuilder.Current.DefaultNamespaces.Add("MyClassLibraryProject.Controllers");
in my global.asax, and i have not implemented any custom solutions proposed by StrathWeb in two of his blog posts, as i think its not applicable any more; because all works just by adding the reference of the controller project to the WebApi project.
So i would expect all to work same for WebApi2 ... but its not. Has anyone really tried doing this in WebAPi2 ?
I have just confirmed that this works fine. Things to check:
References: Does your main Web API project reference the external class library?
Routing: Have you set up any routes that might interfere with the external controllers?
Protection Level: Are the controllers in the external library public?
Inheritance: Do the controllers in the external library inherit from ApiController?
Versioning: Are both your Web API project and class library using the same version of the Web API libraries?
If it helps, I can package up my test solution and make it available to you.
Also, as a point to note, you don't need to tell Web API to find the controllers with the line you added to Global.asax, the system finds the controllers automatically provided you have them referenced.
It should work as is. Checklist
Inherit ApiController
End controller name with Controller. E.g. ValuesController
Make sure WebApi project and class library project reference same WebApi assemblies
Try to force routes using attribute routing
Clean the solution, manually remove bin folders and rebuild
Delete Temporary ASP.NET Files folders. WebApi and MVC cache controller lookup result
Call `config.MapHttpAttributeRoutes(); to ensure framework takes attribute routes into consideration
Make sure that the method you are calling is made to handle correct HTTP Verb (if it is a GET web method, you can call via browser URL, if it is POST you have to otherwise craft a web request)
This controller:
[RoutePrefix("MyValues")]
public class AbcController : ApiController
{
[HttpGet]
[Route("Get")]
public string Get()
{
return "Ok!";
}
}
matches this url:
http://localhost/MyValues/Get (note there is no /api/ in route because it wasn't specified in RoutePrefix.
Controller lookup caching:
This is default controller resolver. You will see in the source code that it caches lookup result.
/// <summary>
/// Returns a list of controllers available for the application.
/// </summary>
/// <returns>An <see cref="ICollection{Type}" /> of controllers.</returns>
public override ICollection<Type> GetControllerTypes(IAssembliesResolver assembliesResolver)
{
HttpControllerTypeCacheSerializer serializer = new HttpControllerTypeCacheSerializer();
// First, try reading from the cache on disk
List<Type> matchingTypes = ReadTypesFromCache(TypeCacheName, IsControllerTypePredicate, serializer);
if (matchingTypes != null)
{
return matchingTypes;
}
...
}
Was running into same scenario and #justmara set me on the right path. Here's how to accomplish the force loading of the dependent assemblies from #justmara's answer:
1) Override the DefaultAssembliesResolver class
public class MyNewAssembliesResolver : DefaultAssembliesResolver
{
public override ICollection<Assembly> GetAssemblies()
{
ICollection<Assembly> baseAssemblies = base.GetAssemblies();
List<Assembly> assemblies = new List<Assembly>(baseAssemblies);
var controllersAssembly = Assembly.LoadFrom(#"Path_to_Controller_DLL");
baseAssemblies.Add(controllersAssembly);
return baseAssemblies;
}
}
2) In the configuration section, replace the default with the new implementation
config.Services.Replace(typeof(IAssembliesResolver), new MyNewAssembliesResolver());
I cobbled this syntax together using pointers from this blog:
http://www.strathweb.com/2013/08/customizing-controller-discovery-in-asp-net-web-api/
As others have said, you know if you are running into this issue if you force the controller to load by directly referencing it. Another way is to example the results of CurrentDomain.GetAssemblies() and see if your assembly is in the list.
Also: If you are self-hosting using OWIN components you WILL run into this. When testing keep in mind that the DefaultAssembliesResolver will NOT kick in until the first WebAPI request is submitted (it took me awhile to realize that).
Are you sure that your referenced assembly was loaded BEFORE IAssembliesResolver service called?
Try to insert some dummy code in your application, something like
var a = new MyClassLibraryProject.Controllers.MyClass();
in configuration method (but don`t forget, that compiler can "optimize" this code and totally remove it, if "a" is never used).
I've had similar issue with assembly loading order. Ended up with force loading dependent assemblies on startup.
You need to tell webapi/mvc to load your referrenced assembly. You do that with the compilation/assemblies section in your web.config.
<compilation debug="true" targetFramework="4.5.2">
<assemblies>
<add assembly="XYZ.SomeAssembly" />
</assemblies>
</compilation>
Simple as that. You can do it with code the way #user1821052 suggested, but this web.config version will have the same effect.
Apart from what has been said already:
Make sure you don't have two controllers of the same name in different namespaces.
Just had the case where one controller (foo.UserApiController) should be partially migrated to a new namespace (bar.UserApiController) and URI. The old controller was mapped by convention to /userapi, the new one was attribute-routed via RoutePrefix["api/users"]. The new controller didn't work until I renamed it to bar.UserFooApiController.
When using AttributeRouting it is easily forgettable to decorate your methods with the Route Attribute, especially when you are using the RoutePrefix Attribute on your controller class. It seems like your controller assembly wasn't picked up by the web api pipeline then.
If your class library is built with EF then make sure you have the connection string specified in the App.config for the class library project, AND in the Web.config for your Web API MVC project.
I am currently running a WCF service on an AppFabric server and my application needs to load a the web.config file dynamically to retrieve custom configuration sections.
On my development machine I can just load the configuration like this:
WebConfigurationManager.OpenMappedWebConfiguration(webMappedFile, virtualPath);
But on the test machine (AppFabric server) I am getting an exception and it seems that I need to specify a third parameter which is actually the site the web application is running on:
WebConfigurationManager.OpenMappedWebConfiguration(webMappedFile, virtualPath, "MySite");
So I tried to hard code it and it worked. Anyway this is not acceptable, so I need to dynamically provide the site to the WebConfigurationManager because I do not on which site the service will be running in the future. Do anybody knows how to achieve that?
Thanks.
If you are running this code as part of handling a request you could use:
Request.ServerVariables("server_name")
see: http://msdn.microsoft.com/en-us/library/ms525396(VS.90).aspx
Edit based on your comment
The parameter that you need is the Site Name, not the machine name, your code be running on many machines. If the code is running somewhere where it no longer knows that it is on a web site, then it is difficult for it to get the name of the web site that it is running on.
You then have two options:
Send the name as a parameter from a layer that has httpconext
Not sure if this will work: but you could try adding a reference to system.web to your project. It may compile, but you could get a null reference exception when you run it. Probably worth a try.
How about Server.MachineName
I'm attempting to create an MVC application as a sub-application to my standard Asp.Net Web application. Both of these projects are inside the same solution. While the parent application appears to be going fine, I'm having trouble getting the sub-application to work. After some massaging of my two web.configs, I was able to get the Asp.Net runtime to accept the configurations, but I have been unable to browse to any of the pages/controllers in the MVC application, including the root of the sub-application ("http://RootSite/SubApplicationName/"). I continually get 404's.
Actually, I do get a response when going to the url "http://RootSite/SubApplicationName/Home/Index/". It redirects me to index.aspx in that folder, and throws this error:
The view 'Index' or its master could not be found. The following locations
were searched:
~/Views/Home/Index.aspx
~/Views/Home/Index.ascx
~/Views/Shared/Index.aspx
~/Views/Shared/Index.ascx
The sub-application in IIS (7) is set up fairly straight forward: it's set to run in the same application pool as the parent app, which runs Asp.Net 2.0 in integration mode.
My suspicion is that I have something in the web.configs that is throwing it off. Are there things regarding, say, HTTPModules or URL authorization modules, etc., that I should confirm aren't getting in the way of MVC?
Also, in the global.asax.cs file, should the default route be different? By default, the url parameter passed to routes.MapRoute is:
"{controller}/{action}/{id}"
Should it be preceded by the name of the sub-application, like so?
"SubApplicationName/{controller}/{action}/{id}"
I attempted a change like that, but it did not fix things.
Any ideas are much appreciated. Also, general information about setting up an MVC web application as a sub-application would be great.
Thanks.
I did something similar, however not the same, I had to load views from a separate dll. In my case it was a class library, not a different web app, but it should work the same as far as I know.
The first thing you have to do is to create a VirtualPath Provider to tell the routing engine how to look for your stuff in the subapplication views. A great explanation of how to do this can be found here:
http://www.wynia.org/wordpress/2008/12/05/aspnet-mvc-plugins/
I'm sure that will get you started ;)
Make sure that you haven't made any spelling mistakes in the names of your Views directories. I was receiving the same error message and after 30 mins of head scratching realized that I had misspelled the folder name for one of my Views. The IDE did not pick this up in any meaningful way (i.e. it would have been nice if it explicitly told me that the path to the view that I was referencing was not correct -- "not found" could mean a few different things).
Sub application doesn't suite to MVC web application directly. you have to write a lot of hacked code in global.asax. Use sub domain rather than sub application.