/// <summary>Modifies the code document object model prior to the contract generation process.</summary>
/// <param name="context">The code generated context to use to modify the code document prior to generation.</param>
public void GenerateContract(ServiceContractGenerationContext context)
{
// Disable generation of the Event-Based Async Pattern, which has a conflicting naming scheme.
context.ServiceContractGenerator.Options &= ~ServiceContractGenerationOptions.EventBasedAsynchronousMethods;
string contractName = context.Contract.Name;
string clientTypeName = TaskAsyncWsdlImportExtension.DeriveClientTypeName(contractName);
// Look up the client class, and create it if it doesn't already exist.
if (TaskAsyncWsdlImportExtension.FindClientType(clientTypeName, context.ServiceContractGenerator.TargetCompileUnit.Namespaces) == null)
{
// Create the new type
CodeTypeDeclaration newClient = new CodeTypeDeclaration(clientTypeName)
{
Attributes = MemberAttributes.Public,
IsPartial = true
};
newClient.BaseTypes.Add(new CodeTypeReference(typeof(ClientBase <>))
{
TypeArguments = { new CodeTypeReference(contractName) }
});
newClient.BaseTypes.Add(new CodeTypeReference(contractName));
// Add the new type to the right namespace
CodeNamespace contractNamespace = (from ns in context.ServiceContractGenerator.TargetCompileUnit.Namespaces.Cast <CodeNamespace>()
from type in ns.Types.Cast <CodeTypeDeclaration>()
where type == context.ContractType
select ns).FirstOrDefault();
contractNamespace.Types.Add(newClient);
}
}
/// <summary>Generates the TAP implementation for a single operation.</summary>
/// <param name="context">Information about the operation.</param>
public void GenerateOperation(OperationContractGenerationContext context)
{
if (context.IsAsync)
{
string contractName = context.Contract.ContractType.Name;
string clientTypeName = TaskAsyncWsdlImportExtension.DeriveClientTypeName(contractName);
// Get the class to contain the new method.
CodeTypeDeclaration clientClass = TaskAsyncWsdlImportExtension.FindClientType(clientTypeName, context.ServiceContractGenerator.TargetCompileUnit.Namespaces);
// First, set up the new method, with attributes, name, parameters, and return type.
CodeMemberMethod newTaskBasedMethod = new CodeMemberMethod()
{
Attributes = MemberAttributes.Final | MemberAttributes.Public,
Name = context.SyncMethod.Name + "Async"
};
newTaskBasedMethod.Parameters.AddRange(context.SyncMethod.Parameters);
bool returnsVoid = context.SyncMethod.ReturnType == null || context.SyncMethod.ReturnType.BaseType == "System.Void";
if (returnsVoid)
{
newTaskBasedMethod.ReturnType = new CodeTypeReference(typeof(Task));
}
else
{
var returnType = new CodeTypeReference(typeof(Task <>));
returnType.TypeArguments.Add(context.EndMethod.ReturnType);
newTaskBasedMethod.ReturnType = returnType;
}
// Second, create the Task.Factory.FromAsync or Task<TResult>.Factory.FromAsync invoker.
CodePropertyReferenceExpression getTaskFactory = new CodePropertyReferenceExpression();
getTaskFactory.PropertyName = "Factory";
CodeMethodInvokeExpression invokeFromAsync = new CodeMethodInvokeExpression();
if (returnsVoid)
{
getTaskFactory.TargetObject = new CodeTypeReferenceExpression(typeof(Task));
}
else
{
var taskOfReturnType = new CodeTypeReference(typeof(Task <>));
taskOfReturnType.TypeArguments.Add(context.SyncMethod.ReturnType);
getTaskFactory.TargetObject = new CodeTypeReferenceExpression(taskOfReturnType);
}
invokeFromAsync.Method = new CodeMethodReferenceExpression(getTaskFactory, "FromAsync");
newTaskBasedMethod.Statements.Add(new CodeMethodReturnStatement(invokeFromAsync));
// Create the end delegate for the FromAsync call.
var endDelegate = new CodeDelegateCreateExpression();
endDelegate.MethodName = context.EndMethod.Name;
endDelegate.TargetObject = new CodeCastExpression(contractName, new CodeThisReferenceExpression());
if (returnsVoid)
{
endDelegate.DelegateType = new CodeTypeReference(typeof(Action <IAsyncResult>));
}
else
{
endDelegate.DelegateType = new CodeTypeReference(typeof(Func <,>));
endDelegate.DelegateType.TypeArguments.Add(typeof(IAsyncResult));
endDelegate.DelegateType.TypeArguments.Add(context.SyncMethod.ReturnType);
}
// If there are <= 3 parameters to the APM's Begin method, use a delegate-based
// overload, as that's what TPL provides overloads for built-in. If not,
// use an overload that accepts an IAsyncResult as the first parameter.
if (context.SyncMethod.Parameters.Count <= 3)
{
// Create the begin delegate for the FromAsync call
// FromAsync(beginDelegate, endDelegate, null);
var beginDelegate = new CodeDelegateCreateExpression();
beginDelegate.MethodName = context.BeginMethod.Name;
beginDelegate.TargetObject = new CodeCastExpression(contractName, new CodeThisReferenceExpression());
switch (context.SyncMethod.Parameters.Count)
{
case 0: beginDelegate.DelegateType = new CodeTypeReference(typeof(Func <, ,>)); break;
case 1: beginDelegate.DelegateType = new CodeTypeReference(typeof(Func <, , ,>)); break;
case 2: beginDelegate.DelegateType = new CodeTypeReference(typeof(Func <, , , ,>)); break;
case 3: beginDelegate.DelegateType = new CodeTypeReference(typeof(Func <, , , , ,>)); break;
}
beginDelegate.DelegateType.TypeArguments.AddRange(context.SyncMethod.Parameters.Cast <CodeParameterDeclarationExpression>().Select(p => p.Type).ToArray());
beginDelegate.DelegateType.TypeArguments.Add(typeof(AsyncCallback));
beginDelegate.DelegateType.TypeArguments.Add(typeof(Object));
beginDelegate.DelegateType.TypeArguments.Add(typeof(IAsyncResult));
invokeFromAsync.Parameters.Add(beginDelegate);
invokeFromAsync.Parameters.Add(endDelegate);
invokeFromAsync.Parameters.AddRange((from parameter in context.SyncMethod.Parameters.Cast <CodeParameterDeclarationExpression>()
select new CodeVariableReferenceExpression(parameter.Name)).ToArray());
invokeFromAsync.Parameters.Add(new CodePrimitiveExpression(null));
}
else // > 3 parameters, so use the IAsyncResult overload
{
// FromAsync(BeginMethod(inputParams, ..., asyncCallback, state), endDelegate)
var invokeBeginExpression = new CodeMethodInvokeExpression(
new CodeMethodReferenceExpression(new CodeCastExpression(contractName, new CodeThisReferenceExpression()), context.BeginMethod.Name));
invokeBeginExpression.Parameters.AddRange((from parameter in context.SyncMethod.Parameters.Cast <CodeParameterDeclarationExpression>()
select new CodeVariableReferenceExpression(parameter.Name)).ToArray());
invokeBeginExpression.Parameters.Add(new CodePrimitiveExpression(null)); // AsyncCallback
invokeBeginExpression.Parameters.Add(new CodePrimitiveExpression(null)); // state
invokeFromAsync.Parameters.Add(invokeBeginExpression);
invokeFromAsync.Parameters.Add(endDelegate);
}
// Finally, add the new method to the class
clientClass.Members.Add(newTaskBasedMethod);
}
}
