public void ShouldBePossibleToChangeObservedStateInActionCalledFromComputedIfRunInsideAllowStateChange()
{
var a = this.sharedState.Box(2);
var d = this.sharedState.Autorun(r =>
{
int i = a.Value;
});
IComputedValue <int> c = null;
IComputedValue <int> c2 = null;
var testAction = this.sharedState.CreateAction(() =>
{
this.sharedState.AllowStateChangesInsideComputed(() =>
{
a.Value = 3;
Assert.Throws <InvalidOperationException>(() =>
{
// Computed values are not allowed to cause side effects by
// changing observables that are already being observed
int i = c2.Value;
});
return(0);
});
Assert.Equal(3, a.Value);
Assert.Throws <InvalidOperationException>(() =>
{
// Computed values are not allowed to cause side effects by
// changing observables that are already being observed/
a.Value = 4;
});
});
c = this.sharedState.Computed(
() =>
{
testAction();
return(a.Value);
}, "computed");
c2 = this.sharedState.Computed(
() =>
{
a.Value = 6;
return(a.Value);
}, "computed");
int j = c.Value;
d.Dispose();
}
public void TestAllowModificationInComputed()
{
var a = ObservableValue <int> .From(2);
var d = Reactions.Autorun(() => { var x = a.Value; });
IComputedValue <int> c2 = null;
var action = Actions.CreateAction("action", () =>
{
Actions.AllowStateChangesInsideComputed(() =>
{
a.Value = 3;
//// a second level computed should throw
Assert.Throws <CaughtException>(() =>
{
// /Computed values are not allowed to cause side effects by changing observables that are already being observed/
var x = c2.Value;
});
});
Assert.Equal(3, a.Value);
Assert.Throws <Exception>(() =>
{
// /Computed values are not allowed to cause side effects by changing observables that are already being observed/
a.Value = 4;
});
});
var c = ComputedValue <int> .From(() =>
{
action();
return(a.Value);
});
c2 = ComputedValue <int> .From(() => {
a.Value = 6;
return(a.Value);
});
var _ = c.Value;
d.Dispose();
}
public TodoStore(HTMLElement root)
{
// Render UI elements:
Render(root);
// Subscribe to Todos changes:
_todos.observe(TodoObserveFn);
// Configure computed field (_completedTodosCount):
_completedTodosCount = computed.Self(() =>
_todos.filter((v, i, arr) => v.Completed ? (object)true : null).Length);
// Configure computed field (_report):
_report = computed.Self(() => $"Progress: {CompletedTodosCount}/{_todos.length}");
// Configure reaction on state changes:
autorun(StageChangedFn);
}
internal StoredReference(StoreType type, object value, IType targetType)
{
Type = type;
Value = value;
TargetType = targetType;
if (Type == StoreType.Object)
{
if (!value.IsStateTreeNode())
{
throw new ArgumentException($"Can only store references to tree nodes, got: '{value}'");
}
var node = value.GetStateTreeNode();
if (string.IsNullOrWhiteSpace(node.IdentifierAttribute))
{
throw new ArgumentException("Can only store references with a defined identifier attribute.");
}
}
_resolvedValue = ComputedValue <object> .From(() =>
{
var identifier = Value?.ToString();
if (string.IsNullOrWhiteSpace(identifier))
{
return(null);
}
// reference was initialized with the identifier of the target
var target = Node.Root.IdentifierCache?.Resolve(TargetType, identifier);
if (target == null)
{
throw new Exception($"Failed to resolve reference '{identifier}' to type '{TargetType.Name}' (from node: {Node.Path})");
}
return(target?.Value);
});
}
