public static IReactionDisposable Reaction(Action expression, Action effect, IReactionOptions <object> options = null)
{
return(Reaction((reaction) =>
{
expression();
return Null;
}, (value, reaction) =>
{
effect();
}, new ReactionOptions <object>()
{
Comparer = new LambdaComparer <object>((a, b) => false)
}));
}
public static IReactionDisposable Reaction <T>(Func <IReactionPublic, T> expression, Action <T, IReactionPublic> effect, IReactionOptions <T> options = null)
{
var name = options?.Name ?? $"Reaction@{States.NextId}";
var runSync = options == null || options.Scheduler != null && options.Delay == 0;
var scheduler = CreateScheduler(options);
var firstTime = true;
var isScheduled = false;
T value = default(T);
var comparer = options?.Comparer ?? EqualityComparer <T> .Default;
var _reaction = new Reaction(
name,
(reaction) =>
{
if (firstTime || runSync)
{
reactionRunner(reaction);
}
else if (!isScheduled)
{
isScheduled = true;
scheduler(() => reactionRunner(reaction));
}
},
options?.OnError
);
void reactionRunner(Reaction reaction)
{
isScheduled = false; // Q: move into reaction runner?
if (reaction.IsDisposed)
{
return;
}
var changed = false;
reaction.Track(() =>
{
var nextValue = expression(reaction);
changed = firstTime || !comparer.Equals(value, nextValue) || Null == (object)nextValue;
value = nextValue;
return(value);
});
var firImmediately = options?.FireImmediately;
if (firstTime && firImmediately.HasValue && firImmediately.Value)
{
effect(value, reaction);
}
if (!firstTime && changed)
{
effect(value, reaction);
}
if (firstTime)
{
firstTime = false;
}
}
_reaction.Schedule();
return(_reaction.GetDisposable());
}
