/// <summary>
/// Check that the method is valid for <see cref="ReactMethodAttribute"/>.
/// </summary>
/// <param name="method">The method.</param>
/// <param name="attribute">The attribute.</param>
public void Validate(MethodInfo method, ReactMethodAttribute attribute)
{
var returnType = method.ReturnType;
if (!attribute.IsBlockingSynchronousMethod && returnType != typeof(void))
{
throw new NotSupportedException("Native module methods must either return void or Task.");
}
var parameters = method.GetParameters();
var n = parameters.Length;
for (var i = 0; i < n; ++i)
{
var parameterType = parameters[i].ParameterType;
if (parameterType == typeof(IPromise) && i != (n - 1))
{
throw new NotSupportedException("Promises are only supported as the last parameter of a native module method.");
}
else if (parameterType == typeof(ICallback) && i != (n - 1))
{
if (i != (n - 2) || parameters[n - 1].ParameterType != typeof(ICallback))
{
throw new NotSupportedException("Callbacks are only supported in the last two positions of a native module method.");
}
}
}
}
public NativeMethod(NativeModuleBase instance, MethodInfo method, ReactMethodAttribute attribute)
{
var delegateFactory = instance._delegateFactory;
delegateFactory.Validate(method, attribute);
_invokeDelegate = new Lazy <Func <IReactInstance, JArray, JToken> >(() => delegateFactory.Create(instance, method));
Type = delegateFactory.GetMethodType(method, attribute);
}
/// <summary>
/// Extracts the native method type from the method.
/// </summary>
/// <param name="method">The method.</param>
/// <param name="attribute">The attribute.</param>
/// <returns>The native method type.</returns>
public string GetMethodType(MethodInfo method, ReactMethodAttribute attribute)
{
if (attribute.IsBlockingSynchronousMethod)
{
return(SyncMethodType);
}
var parameters = method.GetParameters();
if (parameters.Length > 0 && parameters.Last().ParameterType == typeof(IPromise))
{
return(PromiseMethodType);
}
return(AsyncMethodType);
}
/// <summary>
/// Extracts the native method type from the method.
/// </summary>
/// <param name="method">The method.</param>
/// <param name="attribute">The attribute.</param>
/// <returns>The native method type.</returns>
public string GetMethodType(MethodInfo method, ReactMethodAttribute attribute)
{
if (attribute.IsBlockingSynchronousMethod)
{
return(SyncMethodType);
}
if (method.ReturnType == typeof(Task))
{
throw new NotImplementedException("Async methods are not yet supported.");
}
var parameters = method.GetParameters();
if (parameters.Length > 0 && parameters.Last().ParameterType == typeof(IPromise))
{
return(PromiseMethodType);
}
return(AsyncMethodType);
}
