public Task Invoke(IDictionary<string, object> env)
{
var request = new Request(env);
var response = new Response(env) {ContentType = "text/html"};
var wilson = "left - right\r\n123456789012\r\nhello world!\r\n";
var href = "?flip=left";
if (request.Query["flip"] == "left")
{
wilson = wilson.Split(new[] {System.Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries)
.Select(line => new string(line.Reverse().ToArray()))
.Aggregate("", (agg, line) => agg + line + System.Environment.NewLine);
href = "?flip=right";
}
response.Write("<title>Wilson</title>");
response.Write("<pre>");
response.Write(wilson);
response.Write("</pre>");
if (request.Query["flip"] == "crash")
{
throw new ApplicationException("Wilson crashed!");
}
response.Write("<p><a href='" + href + "'>flip!</a></p>");
response.Write("<p><a href='?flip=crash'>crash!</a></p>");
return response.EndAsync();
}
public static AppFunc Middleware(AppFunc app)
{
return env =>
{
Action<Exception, Action<byte[], int, int>> showErrorMessage =
(ex, write) =>
ErrorPage(env, ex, text =>
{
var data = Encoding.ASCII.GetBytes(text);
write(data, 0, data.Length);
});
Func<Exception, Task> showErrorPage = ex =>
{
var response = new Response(env) { Status = "500 Internal Server Error", ContentType = "text/html" };
showErrorMessage(ex, response.Write);
return response.EndAsync();
};
// Don't try to modify the headers after the first write has occurred.
TriggerStream triggerStream = new TriggerStream(env.Get<Stream>(OwinConstants.ResponseBody));
env[OwinConstants.ResponseBody] = triggerStream;
bool bodyHasStarted = false;
triggerStream.OnFirstWrite = () =>
{
bodyHasStarted = true;
};
try
{
return app(env)
.Catch(errorInfo =>
{
if (!bodyHasStarted)
{
showErrorPage(errorInfo.Exception).Wait();
}
else
{
showErrorMessage(errorInfo.Exception, triggerStream.Write);
}
return errorInfo.Handled();
});
}
catch (Exception exception)
{
if (!bodyHasStarted)
{
return showErrorPage(exception);
}
else
{
showErrorMessage(exception, triggerStream.Write);
return TaskHelpers.Completed();
}
}
};
}
public static AppDelegate Middleware(AppDelegate app)
{
return call =>
{
Action<Exception, Action<byte[]>> showErrorMessage =
(ex, write) =>
ErrorPage(call, ex, text =>
{
var data = Encoding.ASCII.GetBytes(text);
write(data);
});
Func<Exception, Task<ResultParameters>> showErrorPage = ex =>
{
var response = new Response() { Status = "500 Internal Server Error", ContentType = "text/html" };
showErrorMessage(ex, data => response.Write(data));
return response.EndAsync();
};
try
{
return app(call)
.Then(result =>
{
if (result.Body != null)
{
var nestedBody = result.Body;
result.Body = stream =>
{
try
{
return nestedBody(stream).Catch(
errorInfo =>
{
showErrorMessage(errorInfo.Exception, data => stream.Write(data, 0, data.Length));
return errorInfo.Handled();
});
}
catch (Exception ex)
{
showErrorMessage(ex, data => stream.Write(data, 0, data.Length));
return TaskHelpers.Completed();
}
};
}
return result;
})
.Catch(errorInfo =>
{
return errorInfo.Handled(showErrorPage(errorInfo.Exception).Result);
});
}
catch (Exception exception)
{
return showErrorPage(exception);
}
};
}
public static Task Call(IDictionary<string, object> env)
{
Response response = new Response(env);
response.StatusCode = 404;
response.ReasonPhrase = "Not Found";
response.Headers.SetHeader("Content-Type", new[] {"text/html"});
response.OutputStream.Write(body, 0, body.Length);
return response.EndAsync();
}
public void Finish_will_call_result_delegate_with_current_status_and_headers()
{
var response = new Response()
{
Status = "200 Blah",
ContentType = "text/blah",
};
ResultParameters result = response.EndAsync().Result;
Assert.That(result.Status, Is.EqualTo(200));
Assert.That(result.Headers.GetHeader("Content-Type"), Is.EqualTo("text/blah"));
}
public void Normal_request_should_pass_through_unchanged()
{
var stack = Build(b => b
.UseShowExceptions()
.UseFunc<AppDelegate>(_ => appCall =>
{
Response appResult = new Response(200);
appResult.Headers.SetHeader("Content-Type", "text/plain");
appResult.Headers.SetHeader("Content-Length", "5");
appResult.Write("Hello");
return appResult.EndAsync();
}));
ResultParameters result = stack(new Request().Call).Result;
Assert.That(result.Status, Is.EqualTo(200));
Assert.That(ReadBody(result.Body), Is.EqualTo("Hello"));
}
public void Write_calls_will_spool_until_finish_is_called()
{
var resp = new Response() { Status = "200 Yep" };
resp.Write("this");
resp.Write("is");
resp.Write("a");
resp.Write("test");
ResultParameters result = resp.EndAsync().Result;
Assert.That(result.Status, Is.EqualTo(200));
var data = Encoding.UTF8.GetString(Consume(result.Body));
Assert.That(data, Is.EqualTo("thisisatest"));
}
private static AppFunc Fail(int status, string body, string headerName = null, string headerValue = null)
{
return env =>
{
Response response = new Response(env);
response.StatusCode = status;
response.Headers
.SetHeader("Content-Type", "text/plain")
.SetHeader("Content-Length", body.Length.ToString(CultureInfo.InvariantCulture))
.SetHeader("X-Cascade", "pass");
if (headerName != null && headerValue != null)
{
response.Headers.SetHeader(headerName, headerValue);
}
response.Write(body);
return response.EndAsync();
};
}
