/// <summary>
/// Returns a promise that resolves when all of the promises in the enumerable argument have resolved.
/// Returns a promise of a collection of the resolved results.
/// </summary>
public static IPromise All(IEnumerable <IPromise> promises)
{
var promisesArray = promises.ToArray();
if (promisesArray.Length == 0)
{
return(Promise.Resolved());
}
var remainingCount = promisesArray.Length;
var resultPromise = new Promise();
resultPromise.WithName("All");
promisesArray.Each((promise, index) =>
{
promise
.Catch(ex =>
{
if (resultPromise.CurState == PromiseState.Pending)
{
// If a promise errorred and the result promise is still pending, reject it.
resultPromise.Reject(ex);
}
})
.Then(() =>
{
--remainingCount;
if (remainingCount <= 0)
{
// This will never happen if any of the promises errorred.
resultPromise.Resolve();
}
})
.Done();
});
return(resultPromise);
}
/// <summary>
/// Return a new promise with a different value.
/// May also change the type of the value.
/// </summary>
public IPromise <ConvertedT> Transform <ConvertedT>(Func <PromisedT, ConvertedT> transform)
{
Argument.NotNull(() => transform);
var resultPromise = new Promise <ConvertedT>();
resultPromise.WithName(Name);
Action <PromisedT> resolveHandler = v =>
{
resultPromise.Resolve(transform(v));
};
Action <Exception> rejectHandler = ex =>
{
resultPromise.Reject(ex);
};
ActionHandlers(resultPromise, resolveHandler, rejectHandler);
return(resultPromise);
}
/// <summary>
/// Add a resolved callback and a rejected callback.
/// The resolved callback chains a non-value promise.
/// </summary>
public IPromise Then(Func <IPromise> onResolved, Action <Exception> onRejected)
{
var resultPromise = new Promise();
resultPromise.WithName(Name);
Action resolveHandler = () =>
{
if (onResolved != null)
{
onResolved()
.Then(
() => resultPromise.Resolve(),
ex => resultPromise.Reject(ex)
)
.Done();
}
else
{
resultPromise.Resolve();
}
};
Action <Exception> rejectHandler = ex =>
{
if (onRejected != null)
{
onRejected(ex);
}
resultPromise.Reject(ex);
};
ActionHandlers(resultPromise, resolveHandler, rejectHandler);
return(resultPromise);
}
/// <summary>
/// Returns a promise that resolves when the first of the promises in the enumerable argument have resolved.
/// Returns the value from the first promise that has resolved.
/// </summary>
public static IPromise Race(IEnumerable <IPromise> promises)
{
var promisesArray = promises.ToArray();
if (promisesArray.Length == 0)
{
throw new ApplicationException("At least 1 input promise must be provided for Race");
}
var resultPromise = new Promise();
resultPromise.WithName("Race");
promisesArray.Each((promise, index) =>
{
promise
.Catch(ex =>
{
if (resultPromise.CurState == PromiseState.Pending)
{
// If a promise errorred and the result promise is still pending, reject it.
resultPromise.Reject(ex);
}
})
.Then(() =>
{
if (resultPromise.CurState == PromiseState.Pending)
{
resultPromise.Resolve();
}
})
.Done();
});
return(resultPromise);
}
/// <summary>
/// Handle errors for the promise.
/// </summary>
public IPromise Catch(Action <Exception> onRejected)
{
Argument.NotNull(() => onRejected);
var resultPromise = new Promise();
resultPromise.WithName(Name);
Action resolveHandler = () =>
{
resultPromise.Resolve();
};
Action <Exception> rejectHandler = ex =>
{
onRejected(ex);
resultPromise.Reject(ex);
};
ActionHandlers(resultPromise, resolveHandler, rejectHandler);
return(resultPromise);
}