public async Task <HttpResponseMessage> ExecuteActionFilterAsync(HttpActionContext actionContext, CancellationToken cancellationToken, Func <Task <HttpResponseMessage> > continuation)
{
// 1. Stuff you do here will happen before the controller action method
HttpResponseMessage response = null;
Debug.WriteLine("VersionCheckFilter: Before controller method");
var keyVersion = actionContext.Request.Headers.FirstOrDefault(v => v.Key == "x-version");
if (keyVersion.Key != null)
{
var s = keyVersion.Value.FirstOrDefault();
if (s.Equals("42"))
{
// 2. Now we send the request to the next link in the chain of filters
// (or to the controller if we are at the end)
response = await continuation();
}
}
if (response == null)
{
var result = new StatusCodeResult((HttpStatusCode)418, actionContext.Request);
response = await result.ExecuteAsync(cancellationToken);
}
// 3. Stuff you do here will happen after the controller action method
Debug.WriteLine("VersionCheckFilter: After controller method");
// 4. Return response thereby continuing back up the chain of filters
return(response);
}
protected override async Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
// 1. Stuff you do here happens before request reaches controller - and filters
HttpResponseMessage response = null;
Debug.WriteLine("First delegating handler - before filters and controller");
var keyVersion = request.Headers.FirstOrDefault(v => v.Key == "x-version");
if (keyVersion.Key != null)
{
var s = keyVersion.Value.FirstOrDefault();
if (s.Equals("42"))
{
// 2. Call the next link in the chain
response = await base.SendAsync(request, cancellationToken);
}
}
if (response == null)
{
var result = new StatusCodeResult((HttpStatusCode)418, request);
response = await result.ExecuteAsync(cancellationToken);
}
// 3. Stuff you do here happens after request reaches controller - and filters
Debug.WriteLine("First delegating handler - after filters and controller");
// 4. Return a response to client
return(response);
}
public void StatusCodeResult_ExecuteResultSetsResponseStatusCode()
{
// Arrange
var result = new StatusCodeResult(StatusCodes.Status404NotFound);
var httpContext = GetHttpContext();
// Act
result.ExecuteAsync(httpContext);
// Assert
Assert.Equal(StatusCodes.Status404NotFound, httpContext.Response.StatusCode);
}
protected override async Task <HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken)
{
HttpResponseMessage response = null;
// Do we have any X-Version headers?
if (request.Headers.Any(h => h.Key == "X-Version"))
{
// Grab first X-Version header
var versionHeader = request.Headers.First(h => h.Key == "X-Version");
// Grab first value of that X-Version header
var version = versionHeader.Value.FirstOrDefault();
// Is that value equal to our magic version value?
if (version != null && version == "42")
{
// Execute remainder of chain, thus generating a response
response = await base.SendAsync(request, cancellationToken);
}
}
// If we get here, the version header was incorrect or missing, so create
// a response saying "I'm a teapot" (we like confusing errors)
if (response == null)
{
// Create a response by using the built-in StatusCodeResult class
var result = new StatusCodeResult((HttpStatusCode)418, request);
response = await result.ExecuteAsync(cancellationToken);
}
// Return response, which will either be result of invoking rest of chain
// or our error response
return(response);
}
