路由控制器asp.net mvc

Question

In our application users can create objects and give them a name. This data is stored in the database with a typeId. I have an api controller that can currently be called, with a name like

api/data

This controller has the basic Get, Put, Post and Delete methods.

Now i would like users to be able to call this controller by object type. So if they setup 3 different objects and call them company, contact and project, i would like them to be able to call the api/data controller, using these names, similar to this

api/company
api/contact
api/project

I do not know these object types unitl runtime, so i cannot code these manually.

Now i also have other controllers that i do not want effected by this, so if i have a normal controller called page, then i still want to be able to call it by

api/page

Is there a way i can do this? Almost intercept a call to a controller, see if the name is equal to a name i have in the database, and if so pass it to the data controller, else let it process as normal.

Answer 1

I think you should

HomeController:

ActionResult Index(string name)
{
// check if name exists in DB
}

I didn't see other way to do what you want even by editing routes... or maybe if you do routes with DB but well...

Answer 2

As far as you are using api controller, you may play with RoutePrefix and Route annotations. For example:

[RoutePrefix("api")]
public class DataController : ApiController
{
    [Route("company")]
    public IEnumerable<CompanyViewModel> GetCompanies() 
    {
    ....
    }
}

But this may conflict with default route definition. If so, try to specifically define your routes for this controller:

 config.Routes.MapHttpRoute(
            name: "CompanyApi",
            routeTemplate: "api/company/{id}",
            defaults: new {controller = "DataController" , id = RouteParameter.Optional}
        );

Answer 3

You would need to add a route for each object in your db, or rather each object not from the db, and have all others route to a default path. You may want to look at using regex with your routing, if you are able to prefix the object names at all.

Answer 4

Web API routing uses fall-through logic, so start off by declaring your known routes first, then have a generic handler to catch all other requests and handle them accordingly. For example, use the following code when setting up your HttpConfiguration :

// Define all known routes using attributes.
config.MapHttpAttributeRoutes();

// Generic route to handle all other requests
config.Routes.MapHttpRoute(
    name: "DynamicRoute",
    routeTemplate: "api/{dataType}",
    defaults: new { controller = "data" }
);

Then in your DataController you can have actions that take the dataType as a parameter:

public async Task<IHttpActionResult> Get(string dataType, ...)
{  ...  }

Answer 5

I have managed to do what i want by using RoutePrefix attribute on controller with an extra MapRoute, with a constraint applied to it.

Here is the code, if someone else is trying to do something similar

First add a routePrefix to the controller that you want to call

[RoutePrefix("api/{myCustomName}")]
public MyController : ApiController { 

}

Now in my WebApiConfig file, i needed to add the following lines

// Web API routes
config.MapHttpAttributeRoutes();

// handle calling MyController using custom name
config.Routes.MapHttpRoute(
    name: "ModuleDataApi",
    routeTemplate: "api/{myCustomName}/{id}",
    defaults: new { controller = "MyController" },
    constraints: new { moduleType = new MyCustomRouteConstraint() }
);

Now create the constraint that checks if there is a valid match. In my code, i have populated a text file with the details if the file doesnt exist, and i will delete/refresh this when a new custom name is added. I believe this would perform better then a database query everytime, since i would probably have about 20 name/value pairs in here at the very most.

So create your constraint like so

public class MyCustomRouteConstraint : IHttpRouteConstraint
{
    private DbContext _context;
    private static object fileLockObject = new object();

    public MyCustomRouteConstraint ()
    {
        _context = new DbContext();
    }

    public bool Match(System.Net.Http.HttpRequestMessage request, IHttpRoute route, string parameterName, IDictionary<string, object> values, HttpRouteDirection routeDirection)
    {
        var appDataPath = System.Web.Hosting.HostingEnvironment.MapPath("~/App_Data/CustomNameRouteCache.txt");

        // lock variable so no 2 or more threads can try to create file at once
        lock (fileLockObject)
        {
            var list = new List<MyRouteModel>();

            // check if our cache file exists, if not, lets create it
            if (!File.Exists(appDataPath))
            {
                using (var writer = new System.IO.StreamWriter(appDataPath))
                {
                    // get all modules
                    var names = _context.CustomNames.ToList();

                    foreach (var item in names)
                    {
                        list.Add(Mapper.Map<MyRouteModel>(item));
                    }

                    // serialize the list to the file in json format
                    var json = JsonConvert.SerializeObject(list);

                    // write to file
                    writer.Write(json);
                };
            }
            else
            {
                // open file and get json contents
                using (var reader = new System.IO.StreamReader(appDataPath))
                {
                    var json = reader.ReadToEnd();

                    list = JsonConvert.DeserializeObject<List<MyRouteModel>>(json);
                }
            }

            // lets search our list and see if this value is in our modules
            foreach (var item in list)
            {
                if (item.Name.Equals(values[parameterName].ToString()))
                {
                    return true;
                }
            }
        }

        return false;
    }
}

Now this seems to work perfectly, i can call MyController using the following paths, or any others that are created by the user at runtime

api/company/
api/contact/
api/project/
api/whateveryouwant/

Hope this help someone else trying to do something similar