/// <summary>
/// Provides the implementation for operations that invoke a member.
/// Classes derived from the <see cref="T:System.Dynamic.DynamicObject"/> class can
/// override this method to specify dynamic behavior for operations such as calling a method.
/// This method should not be called directly, it is called through dynamic method calls.
/// </summary>
/// <param name="binder">
/// Provides information about the dynamic operation.
/// The binder.Name property provides the name of the member on which the dynamic operation is performed.
/// For example, for the statement sampleObject.SampleMethod(100), where sampleObject is an instance of the
/// class derived from the <see cref="T:System.Dynamic.DynamicObject"/> class, binder.Name returns "SampleMethod".
/// The binder.IgnoreCase property specifies whether the member name is case-sensitive.
/// </param>
/// <param name="args">
/// The arguments that are passed to the object member during the invoke operation. For example,
/// for the statement sampleObject.SampleMethod(100), where sampleObject is derived from the
/// <see cref="T:System.Dynamic.DynamicObject"/> class, the first argument to <paramref name="args"/> is equal to 100.
/// </param>
/// <param name="result">The result of the member invocation.</param>
/// <returns>
/// true if the operation is successful; otherwise, false. If this method returns false, the run-time
/// binder of the language determines the behavior. (In most cases, a language-specific run-time exception is thrown.)
/// </returns>
/// <exception cref="InvalidOperationException">
/// Dynamic method is called with non-named argument.
/// All parameters must be passed as name arguments to API calls.
/// - or -
/// The dynamic method name was not in the correct format.
/// All API function calls must be in the format 'FunctionName###' where the optional ###'s represent a version number.
/// </exception>
/// <exception cref="ArgumentException">
/// The reserved named parameter 'secure' was not a boolean value.
/// This parameter is used when requests must go through the secure API.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// The function version number specified was out of range.
/// </exception>
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
bool success = asyncInterface.TryInvokeMember(binder, args, out result);
// the async interface's return of TryInvokeMember will be a Task<KeyValue>, but users of this interface class
// expect a non-future KeyValue, so we need to duplicate the timeout handling logic here
// to return a KeyValue, or throw an exception
Task <KeyValue> resultTask = result as Task <KeyValue>;
try
{
bool completed = resultTask.Wait(Timeout);
if (!completed)
{
throw new TimeoutException("The WebAPI call timed out");
}
}
catch (AggregateException ex) when(ex.InnerException != null)
{
// because we're internally using the async interface, any WebExceptions thrown will
// be wrapped inside an AggregateException.
// since callers don't expect this, we need to unwrap and rethrow the inner exception
ExceptionDispatchInfo.Capture(ex.InnerException).Throw();
}
result = resultTask.Result;
return(success);
}
/// <summary>
/// Provides the implementation for operations that invoke a member.
/// Classes derived from the <see cref="T:System.Dynamic.DynamicObject"/> class can
/// override this method to specify dynamic behavior for operations such as calling a method.
/// This method should not be called directly, it is called through dynamic method calls.
/// </summary>
/// <param name="binder">
/// Provides information about the dynamic operation.
/// The binder.Name property provides the name of the member on which the dynamic operation is performed.
/// For example, for the statement sampleObject.SampleMethod(100), where sampleObject is an instance of the
/// class derived from the <see cref="T:System.Dynamic.DynamicObject"/> class, binder.Name returns "SampleMethod".
/// The binder.IgnoreCase property specifies whether the member name is case-sensitive.
/// </param>
/// <param name="args">
/// The arguments that are passed to the object member during the invoke operation. For example,
/// for the statement sampleObject.SampleMethod(100), where sampleObject is derived from the
/// <see cref="T:System.Dynamic.DynamicObject"/> class, the first argument to <paramref name="args"/> is equal to 100.
/// </param>
/// <param name="result">The result of the member invocation.</param>
/// <returns>
/// true if the operation is successful; otherwise, false. If this method returns false, the run-time
/// binder of the language determines the behavior. (In most cases, a language-specific run-time exception is thrown.)
/// </returns>
/// <exception cref="InvalidOperationException">
/// Dynamic method is called with non-named argument.
/// All parameters must be passed as name arguments to API calls.
/// - or -
/// The dynamic method name was not in the correct format.
/// All API function calls must be in the format 'FunctionName###' where the optional ###'s represent a version number.
/// </exception>
/// <exception cref="ArgumentException">
/// The reserved named parameter 'secure' was not a boolean value.
/// This parameter is used when requests must go through the secure API.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// The function version number specified was out of range.
/// </exception>
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
bool success = asyncInterface.TryInvokeMember(binder, args, out result);
// the async interface's return of TryInvokeMember will be a Task<KeyValue>, but users of this interface class
// expect a non-future KeyValue, so we need to duplicate the timeout handling logic here
// to return a KeyValue, or throw an exception
Task <KeyValue> resultTask = result as Task <KeyValue>;
try
{
bool completed = resultTask.Wait(Timeout);
if (!completed)
{
throw new WebException("The WebAPI call timed out", WebExceptionStatus.Timeout);
}
}
catch (AggregateException ex)
{
// because we're internally using the async interface, any WebExceptions thrown will
// be wrapped inside an AggregateException.
// since callers don't expect this, we need to unwrap and rethrow the inner exception
var innerEx = ex.InnerException;
// preserve stack trace when rethrowing inner exception
// see: http://stackoverflow.com/a/4557183/139147
var prepFunc = typeof(Exception).GetMethod("PrepForRemoting", BindingFlags.NonPublic | BindingFlags.Instance);
if (prepFunc != null)
{
// TODO: we can't use this on mono!
// .NET 4.5 comes with the machinery to preserve a stack trace: ExceptionDispatchInfo, but we target 4.0
prepFunc.Invoke(innerEx, new object[0]);
}
throw innerEx;
}
result = resultTask.Result;
return(success);
}
