// TODO DM 24.11.2019: This would require another bunch of reflection code to get working...
/*
* public TaskAwaiter GetAwaiter()
* {
* if (TryConvertIntern(typeof(Task), out object task))
* {
* return ((Task)task).GetAwaiter();
* }
* throw new InvalidOperationException("JS object is not awaitable");
* }*/
internal bool TryConvertIntern(Type type, out object result)
{
// Converting to string.
if (type == typeof(object) || type.IsAssignableFrom(GetType()))
{
result = this;
return(true);
}
//Console.WriteLine($"Converting to {type.Name}");
if (type == typeof(string))
{
var jsResult = _host.InvokeByName("String",
JsValue.Global,
1,
new DotNetValue[]
{
DotNetValue.FromJsValue(Handle)
});
var gotString = jsResult.TryGetObject(_host, typeof(string), out result);
if (!gotString)
{
return(false);
}
return(result is string);
}
if (typeof(Task).IsAssignableFrom(type))
{
var thenHandle = _host.GetMember(Handle, "then");
try
{
// Ensure that Handle is a thenable/promise like object
if (thenHandle.Type == JsType.Function)
{
if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Task <>))
{
// TODO DM 24.11.2019: This is inefficient. We need to do this in the native code somehow...
// How about _host.AttachTaskToPromise(Action<JsValue>,Action<JsValue>)?
var resultType = type.GetGenericArguments()[0];
var completionSourceType = typeof(TaskCompletionSource <>).MakeGenericType(resultType);
var tcs = Activator.CreateInstance(completionSourceType);
var resolve = Delegate.CreateDelegate(typeof(Action <>).MakeGenericType(resultType),
tcs,
completionSourceType.GetMethod(nameof(TaskCompletionSource <object> .SetResult)));
var reject = new Action <object>(error =>
{
completionSourceType.GetMethod(nameof(TaskCompletionSource <object> .SetException))
.Invoke(tcs, new object[] { GetExceptionFromPromiseRejection(error) });
});
var thenResult = _host.Invoke(thenHandle,
Handle,
2,
new[]
{
DotNetValue.FromDelegate(resolve, _host),
DotNetValue.FromDelegate(reject, _host)
});
// DM 29.11.2019: thenResult is always another promise
_host.Release(thenResult);
result = completionSourceType.GetProperty(nameof(TaskCompletionSource <object> .Task))
.GetValue(tcs);
return(true);
}
else
{
var tcs = new TaskCompletionSource <object>();
var thenResult = _host.Invoke(thenHandle,
Handle,
2,
new DotNetValue[]
{
DotNetValue.FromDelegate(new Action(() => tcs.SetResult(null)), _host),
DotNetValue.FromDelegate(new Action <object>((error) => { tcs.SetException(GetExceptionFromPromiseRejection(error)); }), _host)
});
// DM 29.11.2019: thenResult is always another promise
_host.Release(thenResult);
result = tcs.Task;
return(true);
}
}
}
finally
{
_host.Release(thenHandle);
}
result = null;
return(false);
}
if (typeof(Exception).IsAssignableFrom(type))
{
dynamic dynamic = this;
string stack = dynamic.stack;
if (stack != null)
{
result = new InvalidOperationException($"JS Error:\n{stack}");
return(true);
}
result = null;
return(false);
}
if (type.IsArray)
{
var innerType = type.GetElementType();
if (TryConvertToArray(innerType, out result))
{
return(true);
}
result = null;
return(false);
}
if (type.IsGenericType && type.IsInterface)
{
var unclosed = type.GetGenericTypeDefinition();
if (unclosed == typeof(IEnumerable <>) || unclosed == typeof(IReadOnlyCollection <>))
{
var innerType = type.GetGenericArguments()[0];
if (TryConvertToArray(innerType, out result))
{
return(true);
}
}
result = null;
return(false);
}
result = null;
return(false);
}
