internal static object[] BindParameter(HttpContext httpContext, ILightNodeOptions options, IOperationCoordinator coordinator, ValueProvider valueProvider, ParameterInfoSlim[] arguments)
        {
            var methodParameters = new object[arguments.Length];

            for (int i = 0; i < arguments.Length; i++)
            {
                var item = arguments[i];

                var _values = valueProvider.GetValue(item.Name);
                var value   = _values as string;
                var values  = _values as List <string>;
                var isEmpty = _values == null;

                if (isEmpty && !item.ParameterTypeIsArray)
                {
                    if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        coordinator.OnProcessInterrupt(options, httpContext, InterruptReason.ParameterBindMissing, "Lack of Parameter:" + item.Name);
                        options.Logger.ParameterBindMissing(OperationMissingKind.LackOfParameter, item.Name);
                        if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ThrowException)
                        {
                            throw new ParameterMissingException(OperationMissingKind.LackOfParameter, item.Name);
                        }
                        else
                        {
                            httpContext.EmitBadRequest();
                            if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ReturnErrorStatusCodeIncludeErrorDetails)
                            {
                                httpContext.EmitStringMessage("Lack of Parameter:" + item.Name);
                            }
                            return(null);
                        }
                    }
                }
                else if (!item.ParameterTypeIsArray)
                {
                    var conv = TypeBinder.GetConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                    if (conv == null)
                    {
                        throw new InvalidOperationException("critical:register code is broken");
                    }

                    object pValue;
                    if (conv(value ?? values[0], out pValue))
                    {
                        methodParameters[i] = pValue;
                        continue;
                    }
                    else if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        coordinator.OnProcessInterrupt(options, httpContext, InterruptReason.ParameterBindMissing, "Mismatch ParameterType:" + item.Name);
                        options.Logger.ParameterBindMissing(OperationMissingKind.MissmatchParameterType, item.Name);
                        if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ThrowException)
                        {
                            throw new ParameterMissingException(OperationMissingKind.MissmatchParameterType, item.Name);
                        }
                        else
                        {
                            httpContext.EmitBadRequest();
                            if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ReturnErrorStatusCodeIncludeErrorDetails)
                            {
                                httpContext.EmitStringMessage("Mismatch ParameterType:" + item.Name);
                            }
                            return(null);
                        }
                    }
                }

                var arrayConv = TypeBinder.GetArrayConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                if (arrayConv == null)
                {
                    throw new InvalidOperationException("critical:register code is broken");
                }

                methodParameters[i] = arrayConv((values != null) ? values : (value != null) ? new[] { value } : (IList <string>) new string[0]);
                continue;
            }

            return(methodParameters);
        }
Exemple #2
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        internal static object[] BindParameter(IDictionary<string, object> environment, ILightNodeOptions options, IOperationCoordinator coordinator, ValueProvider valueProvider, ParameterInfoSlim[] arguments)
        {
            var methodParameters = new object[arguments.Length];
            for (int i = 0; i < arguments.Length; i++)
            {
                var item = arguments[i];

                var _values = valueProvider.GetValue(item.Name);
                var value = _values as string;
                var values = _values as List<string>;
                var isEmpty = _values == null;
                var byteArray = _values as byte[];

                // TODO:Experimental support
                if (byteArray != null && item.ParameterTypeIsArray && item.ParameterType == typeof(byte[]))
                {
                    methodParameters[i] = byteArray;
                    continue;
                }

                if (isEmpty && !item.ParameterTypeIsArray)
                {
                    if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        coordinator.OnProcessInterrupt(options, environment, InterruptReason.ParameterBindMissing, "Lack of Parameter:" + item.Name);
                        options.Logger.ParameterBindMissing(OperationMissingKind.LackOfParameter, item.Name);
                        if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ThrowException)
                        {
                            throw new ParameterMissingException(OperationMissingKind.LackOfParameter, item.Name);
                        }
                        else
                        {
                            environment.EmitBadRequest();
                            if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ReturnErrorStatusCodeIncludeErrorDetails)
                            {
                                environment.EmitStringMessage("Lack of Parameter:" + item.Name);
                            }
                            return null;
                        }
                    }
                }
                else if (!item.ParameterTypeIsArray)
                {
                    var conv = TypeBinder.GetConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                    if (conv == null) throw new InvalidOperationException("critical:register code is broken");

                    object pValue;
                    if (conv(value ?? values[0], out pValue))
                    {
                        methodParameters[i] = pValue;
                        continue;
                    }
                    else if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        coordinator.OnProcessInterrupt(options, environment, InterruptReason.ParameterBindMissing, "Mismatch ParameterType:" + item.Name);
                        options.Logger.ParameterBindMissing(OperationMissingKind.MissmatchParameterType, item.Name);
                        if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ThrowException)
                        {
                            throw new ParameterMissingException(OperationMissingKind.MissmatchParameterType, item.Name);
                        }
                        else
                        {
                            environment.EmitBadRequest();
                            if (options.OperationMissingHandlingPolicy == OperationMissingHandlingPolicy.ReturnErrorStatusCodeIncludeErrorDetails)
                            {
                                environment.EmitStringMessage("Mismatch ParameterType:" + item.Name);
                            }
                            return null;
                        }
                    }
                }

                var arrayConv = TypeBinder.GetArrayConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                if (arrayConv == null) throw new InvalidOperationException("critical:register code is broken");

                methodParameters[i] = arrayConv((values != null) ? values : (value != null) ? new[] { value } : (IList<string>)new string[0]);
                continue;
            }

            return methodParameters;
        }
Exemple #3
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        // Routing -> ParameterBinding -> Execute
        public async Task<bool> ProcessRequest(IDictionary<string, object> environment)
        {
            options.Logger.ProcessRequestStart(environment.AsRequestPath());

            MemoryStream bufferedRequestStream = null;
            var originalRequestStream = environment.AsRequestBody();
            if (!originalRequestStream.CanSeek)
            {
                bufferedRequestStream = new MemoryStream();
                if (options.StreamWriteOption == StreamWriteOption.BufferAndAsynchronousWrite)
                {
                    await originalRequestStream.CopyToAsync(bufferedRequestStream); // keep context
                }
                else
                {
                    originalRequestStream.CopyTo(bufferedRequestStream);
                }
                bufferedRequestStream.Position = 0;
                environment[OwinConstants.RequestBody] = bufferedRequestStream;
            }
            try
            {
                var coordinator = options.OperationCoordinatorFactory.Create();
                if (!coordinator.OnStartProcessRequest(options, environment))
                {
                    return ReturnNextMiddleware(environment);
                }

                AcceptVerbs verb;
                string ext;
                var handler = SelectHandler(environment, coordinator, out verb, out ext);
                if (handler == null) return ReturnNextMiddleware(environment);

                // Parameter binding
                var valueProvider = new ValueProvider(environment, verb);
                var methodParameters = ParameterBinder.BindParameter(environment, options, coordinator, valueProvider, handler.Arguments);
                if (methodParameters == null) return ReturnNextMiddleware(environment);

                // select formatter
                var formatter = handler.NegotiateFormat(environment, ext, options, coordinator);
                if (formatter == null)
                {
                    if (formatter == null) return ReturnNextMiddleware(environment);
                }

                try
                {
                    // Operation execute
                    var context = new OperationContext(environment, handler.ClassName, handler.MethodName, verb)
                    {
                        Parameters = methodParameters,
                        ParameterNames = handler.ParameterNames,
                        ContentFormatter = formatter,
                        Attributes = handler.AttributeLookup
                    };
                    var executionPath = context.ToString();
                    options.Logger.ExecuteStart(executionPath);
                    var sw = Stopwatch.StartNew();
                    var interrupted = false;
                    try
                    {
                        await handler.Execute(options, context, coordinator).ConfigureAwait(false);
                    }
                    catch
                    {
                        interrupted = true;
                        throw;
                    }
                    finally
                    {
                        sw.Stop();
                        options.Logger.ExecuteFinished(executionPath, interrupted, sw.Elapsed.TotalMilliseconds);
                    }
                    return ReturnNextMiddleware(environment);
                }
                catch (ReturnStatusCodeException statusException)
                {
                    try
                    {
                        if (options.UseOtherMiddleware && options.PassThroughWhenStatusCodesAre != null)
                        {
                            var code = (int)statusException.StatusCode;
                            for (int i = 0; i < options.PassThroughWhenStatusCodesAre.Length; i++)
                            {
                                if (code == options.PassThroughWhenStatusCodesAre[i])
                                {
                                    environment[OwinConstants.ResponseStatusCode] = code; // emit only code.
                                    return ReturnNextMiddleware(environment);
                                }
                            }
                        }

                        statusException.EmitCode(options, environment);
                    }
                    catch (Exception ex)
                    {
                        if (IsRethrowOrEmitException(coordinator, options, environment, ex))
                        {
                            throw;
                        }
                    }
                }
                catch (Exception ex)
                {
                    if (IsRethrowOrEmitException(coordinator, options, environment, ex))
                    {
                        throw;
                    }
                }
            }
            finally
            {
                if (bufferedRequestStream != null)
                {
                    bufferedRequestStream.Dispose();
                }
                environment[OwinConstants.RequestBody] = originalRequestStream;
            }

            return ReturnNextMiddleware(environment);
        }
Exemple #4
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        // Routing -> ParameterBinding -> Execute
        public async Task ProcessRequest(IDictionary <string, object> environment)
        {
            options.Logger.ProcessRequestStart(environment.AsRequestPath());

            MemoryStream bufferedRequestStream = null;
            var          originalRequestStream = environment.AsRequestBody();

            if (!originalRequestStream.CanSeek)
            {
                bufferedRequestStream = new MemoryStream();
                if (options.StreamWriteOption == StreamWriteOption.BufferAndAsynchronousWrite)
                {
                    await originalRequestStream.CopyToAsync(bufferedRequestStream); // keep context
                }
                else
                {
                    originalRequestStream.CopyTo(bufferedRequestStream);
                }
                bufferedRequestStream.Position         = 0;
                environment[OwinConstants.RequestBody] = bufferedRequestStream;
            }
            try
            {
                var coordinator = options.OperationCoordinatorFactory.Create();
                if (!coordinator.OnStartProcessRequest(options, environment))
                {
                    return;
                }

                AcceptVerbs verb;
                string      ext;
                var         handler = SelectHandler(environment, coordinator, out verb, out ext);
                if (handler == null)
                {
                    return;
                }

                // Parameter binding
                var valueProvider    = new ValueProvider(environment, verb);
                var methodParameters = ParameterBinder.BindParameter(environment, options, coordinator, valueProvider, handler.Arguments);
                if (methodParameters == null)
                {
                    return;
                }

                // select formatter
                var formatter = handler.NegotiateFormat(environment, ext, options, coordinator);
                if (formatter == null)
                {
                    if (formatter == null)
                    {
                        return;
                    }
                }

                try
                {
                    // Operation execute
                    var context = new OperationContext(environment, handler.ClassName, handler.MethodName, verb)
                    {
                        Parameters       = methodParameters,
                        ParameterNames   = handler.ParameterNames,
                        ContentFormatter = formatter,
                        Attributes       = handler.AttributeLookup
                    };
                    var executionPath = context.ToString();
                    options.Logger.ExecuteStart(executionPath);
                    var sw          = Stopwatch.StartNew();
                    var interrupted = false;
                    try
                    {
                        await handler.Execute(options, context, coordinator).ConfigureAwait(false);
                    }
                    catch
                    {
                        interrupted = true;
                        throw;
                    }
                    finally
                    {
                        sw.Stop();
                        options.Logger.ExecuteFinished(executionPath, interrupted, sw.Elapsed.TotalMilliseconds);
                    }
                    return;
                }
                catch (ReturnStatusCodeException statusException)
                {
                    try
                    {
                        statusException.EmitCode(options, environment);
                    }
                    catch (Exception ex)
                    {
                        if (IsRethrowOrEmitException(coordinator, options, environment, ex))
                        {
                            throw;
                        }
                    }
                }
                catch (Exception ex)
                {
                    if (IsRethrowOrEmitException(coordinator, options, environment, ex))
                    {
                        throw;
                    }
                }
            }
            finally
            {
                if (bufferedRequestStream != null)
                {
                    bufferedRequestStream.Dispose();
                }
                environment[OwinConstants.RequestBody] = originalRequestStream;
            }
        }
Exemple #5
0
        // Routing -> ParameterBinding -> Execute
        public async Task <bool> ProcessRequest(HttpContext httpContext)
        {
            options.Logger.ProcessRequestStart(httpContext.Request.Path);

            MemoryStream bufferedRequestStream = null;
            var          originalRequestStream = httpContext.Request.Body;

            if (!originalRequestStream.CanSeek)
            {
                bufferedRequestStream = new MemoryStream();
                if (options.StreamWriteOption == StreamWriteOption.BufferAndAsynchronousWrite)
                {
                    await originalRequestStream.CopyToAsync(bufferedRequestStream); // keep context
                }
                else
                {
                    originalRequestStream.CopyTo(bufferedRequestStream);
                }
                bufferedRequestStream.Position = 0;
                httpContext.Request.Body       = bufferedRequestStream;
            }
            try
            {
                var coordinator = options.OperationCoordinatorFactory.Create();
                if (!coordinator.OnStartProcessRequest(options, httpContext))
                {
                    return(ReturnNextMiddleware(httpContext));
                }

                AcceptVerbs verb;
                string      ext;
                var         handler = SelectHandler(httpContext, coordinator, out verb, out ext);
                if (handler == null)
                {
                    return(ReturnNextMiddleware(httpContext));
                }

                // Parameter binding
                var valueProvider    = new ValueProvider(httpContext, verb);
                var methodParameters = ParameterBinder.BindParameter(httpContext, options, coordinator, valueProvider, handler.Arguments);
                if (methodParameters == null)
                {
                    return(ReturnNextMiddleware(httpContext));
                }

                // select formatter
                var formatter = handler.NegotiateFormat(httpContext, ext, options, coordinator);
                if (formatter == null)
                {
                    if (formatter == null)
                    {
                        return(ReturnNextMiddleware(httpContext));
                    }
                }

                try
                {
                    // Operation execute
                    var context = new OperationContext(httpContext, handler.ClassName, handler.MethodName, verb)
                    {
                        Parameters       = methodParameters,
                        ParameterNames   = handler.ParameterNames,
                        ContentFormatter = formatter,
                        Attributes       = handler.AttributeLookup
                    };
                    var executionPath = context.ToString();
                    options.Logger.ExecuteStart(executionPath);
                    var sw          = Stopwatch.StartNew();
                    var interrupted = false;
                    try
                    {
                        await handler.Execute(options, context, coordinator).ConfigureAwait(false);
                    }
                    catch
                    {
                        interrupted = true;
                        throw;
                    }
                    finally
                    {
                        sw.Stop();
                        options.Logger.ExecuteFinished(executionPath, interrupted, sw.Elapsed.TotalMilliseconds);
                    }
                    return(ReturnNextMiddleware(httpContext));
                }
                catch (ReturnStatusCodeException statusException)
                {
                    try
                    {
                        if (options.UseOtherMiddleware && options.PassThroughWhenStatusCodesAre != null)
                        {
                            var code = (int)statusException.StatusCode;
                            for (int i = 0; i < options.PassThroughWhenStatusCodesAre.Length; i++)
                            {
                                if (code == options.PassThroughWhenStatusCodesAre[i])
                                {
                                    httpContext.Response.StatusCode = code; // emit only code.
                                    return(ReturnNextMiddleware(httpContext));
                                }
                            }
                        }

                        statusException.EmitCode(options, httpContext);
                    }
                    catch (Exception ex)
                    {
                        if (IsRethrowOrEmitException(coordinator, options, httpContext, ex))
                        {
                            throw;
                        }
                    }
                }
                catch (Exception ex)
                {
                    if (IsRethrowOrEmitException(coordinator, options, httpContext, ex))
                    {
                        throw;
                    }
                }
            }
            finally
            {
                if (bufferedRequestStream != null)
                {
                    bufferedRequestStream.Dispose();
                }
                httpContext.Request.Body = originalRequestStream;
            }

            return(ReturnNextMiddleware(httpContext));
        }
        // Routing -> ParameterBinding -> Execute
        public async Task ProcessRequest(IDictionary<string, object> environment)
        {
            try
            {
                AcceptVerbs verb;
                string ext;
                var handler = SelectHandler(environment, out verb, out ext);
                if (handler == null) return;

                // verb check | TODO:check operation verb attribute
                if (!options.DefaultAcceptVerb.HasFlag(verb))
                {
                    environment.EmitMethodNotAllowed();
                    return;
                }

                // Parameter binding
                var valueProvider = new ValueProvider(environment, verb);
                var methodParameters = ParameterBinder.BindParameter(environment, options, valueProvider, handler.Arguments);
                if (methodParameters == null) return;

                // select formatter
                var formatter = NegotiateFormat(environment, ext);
                if (formatter == null) return;

                // Operation execute
                var context = new OperationContext(environment, handler.ClassName, handler.MethodName, verb)
                {
                    Parameters = methodParameters,
                    ContentFormatter = formatter,
                    Attributes = handler.AttributeLookup
                };
                await handler.Execute(options, context).ConfigureAwait(false);
                return;
            }
            catch (ReturnStatusCodeException statusException)
            {
                statusException.EmitCode(environment);
                return;
            }
            catch (Exception ex)
            {
                switch (options.ErrorHandlingPolicy)
                {
                    case ErrorHandlingPolicy.ReturnInternalServerError:
                        environment.EmitInternalServerError();
                        return;
                    case ErrorHandlingPolicy.ReturnInternalServerErrorIncludeErrorDetails:
                        environment.EmitInternalServerError();
                        environment.EmitStringMessage(ex.ToString());
                        return;
                    case ErrorHandlingPolicy.ThrowException:
                    default:
                        throw;
                }
            }
        }
        internal static object[] BindParameter(IDictionary<string, object> environment, LightNodeOptions options, ValueProvider valueProvider, ParameterInfoSlim[] arguments)
        {
            var methodParameters = new object[arguments.Length];
            for (int i = 0; i < arguments.Length; i++)
            {
                var item = arguments[i];

                var _values = valueProvider.GetValue(item.Name);
                var value = _values as string;
                var values = _values as List<string>;
                var isEmpty = _values == null;

                if (isEmpty && !item.ParameterTypeIsArray)
                {
                    if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        environment.EmitBadRequest();
                        environment.EmitStringMessage("Lack of Parameter:" + item.Name);
                        return null;
                    }
                }
                else if (!item.ParameterTypeIsArray)
                {
                    var conv = TypeBinder.GetConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                    if (conv == null) throw new InvalidOperationException("critical:register code is broken");

                    object pValue;
                    if (conv(value ?? values[0], out pValue))
                    {
                        methodParameters[i] = pValue;
                        continue;
                    }
                    else if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        environment.EmitBadRequest();
                        environment.EmitStringMessage("Mismatch Parameter Type:" + item.Name);
                        return null;
                    }
                }

                var arrayConv = TypeBinder.GetArrayConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                if (arrayConv == null) throw new InvalidOperationException("critical:register code is broken");

                methodParameters[i] = arrayConv((values != null) ? values : (value != null) ? new[] { value } : Enumerable.Empty<string>());
                continue;
            }

            return methodParameters;
        }
        internal static object[] BindParameter(IDictionary <string, object> environment, LightNodeOptions options, ValueProvider valueProvider, ParameterInfoSlim[] arguments)
        {
            var methodParameters = new object[arguments.Length];

            for (int i = 0; i < arguments.Length; i++)
            {
                var item = arguments[i];

                var _values = valueProvider.GetValue(item.Name);
                var value   = _values as string;
                var values  = _values as List <string>;
                var isEmpty = _values == null;

                if (isEmpty && !item.ParameterTypeIsArray)
                {
                    if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        environment.EmitBadRequest();
                        environment.EmitStringMessage("Lack of Parameter:" + item.Name);
                        return(null);
                    }
                }
                else if (!item.ParameterTypeIsArray)
                {
                    var conv = TypeBinder.GetConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                    if (conv == null)
                    {
                        throw new InvalidOperationException("critical:register code is broken");
                    }

                    object pValue;
                    if (conv(value ?? values[0], out pValue))
                    {
                        methodParameters[i] = pValue;
                        continue;
                    }
                    else if (item.IsOptional)
                    {
                        methodParameters[i] = item.DefaultValue;
                        continue;
                    }
                    else if ((!item.ParameterTypeIsString || options.ParameterStringImplicitNullAsDefault) && (item.ParameterTypeIsClass || item.ParameterTypeIsNullable))
                    {
                        methodParameters[i] = null;
                        continue;
                    }
                    else
                    {
                        environment.EmitBadRequest();
                        environment.EmitStringMessage("Mismatch Parameter Type:" + item.Name);
                        return(null);
                    }
                }

                var arrayConv = TypeBinder.GetArrayConverter(item.ParameterType, !options.ParameterEnumAllowsFieldNameParse);
                if (arrayConv == null)
                {
                    throw new InvalidOperationException("critical:register code is broken");
                }

                methodParameters[i] = arrayConv((values != null) ? values : (value != null) ? new[] { value } : Enumerable.Empty <string>());
                continue;
            }

            return(methodParameters);
        }
        // Routing -> ParameterBinding -> Execute
        public async Task ProcessRequest(IDictionary <string, object> environment)
        {
            try
            {
                AcceptVerbs verb;
                string      ext;
                var         handler = SelectHandler(environment, out verb, out ext);
                if (handler == null)
                {
                    return;
                }

                // verb check | TODO:check operation verb attribute
                if (!options.DefaultAcceptVerb.HasFlag(verb))
                {
                    environment.EmitMethodNotAllowed();
                    return;
                }

                // Parameter binding
                var valueProvider    = new ValueProvider(environment, verb);
                var methodParameters = ParameterBinder.BindParameter(environment, options, valueProvider, handler.Arguments);
                if (methodParameters == null)
                {
                    return;
                }

                // select formatter
                var formatter = NegotiateFormat(environment, ext);
                if (formatter == null)
                {
                    return;
                }

                // Operation execute
                var context = new OperationContext(environment, handler.ClassName, handler.MethodName, verb)
                {
                    Parameters       = methodParameters,
                    ContentFormatter = formatter,
                    Attributes       = handler.AttributeLookup
                };
                await handler.Execute(options, context).ConfigureAwait(false);

                return;
            }
            catch (ReturnStatusCodeException statusException)
            {
                statusException.EmitCode(environment);
                return;
            }
            catch (Exception ex)
            {
                switch (options.ErrorHandlingPolicy)
                {
                case ErrorHandlingPolicy.ReturnInternalServerError:
                    environment.EmitInternalServerError();
                    return;

                case ErrorHandlingPolicy.ReturnInternalServerErrorIncludeErrorDetails:
                    environment.EmitInternalServerError();
                    environment.EmitStringMessage(ex.ToString());
                    return;

                case ErrorHandlingPolicy.ThrowException:
                default:
                    throw;
                }
            }
        }