/// Wraps the expression in `dotvvm.evaluator.wrapExpression` if needed
public static JsExpression EnsureObservableWrapped(this JsExpression expression) =>
// It's not needed to wrap if none of the descendants return an observable
!expression.DescendantNodes().Any(n => (n.HasAnnotation <ResultIsObservableAnnotation>() && !n.HasAnnotation <ShouldBeObservableAnnotation>()) || n.HasAnnotation <ObservableUnwrapInvocationAnnotation>()) ?
expression.WithAnnotation(ShouldBeObservableAnnotation.Instance) :
new JsIdentifierExpression("dotvvm").Member("evaluator").Member("wrapKnockoutExpression").Invoke(new JsFunctionExpression(
parameters: Enumerable.Empty <JsIdentifier>(),
bodyBlock: new JsBlockStatement(new JsReturnStatement(expression))))
.WithAnnotation(ResultIsObservableAnnotation.Instance)
.WithAnnotation(ShouldBeObservableAnnotation.Instance);
/// Wraps the expression in `dotvvm.evaluator.wrapObservable` if needed
/// Note that this method may be used to process nodes that are already fully handled by all the transformation regarding observables -> it's fine to use to post-process a generate expression, but you shall not use it in custom method translator (see <see cref="ObservableTransformationAnnotation.EnsureWrapped"/> annotation instead)
public static JsExpression EnsureObservableWrapped(this JsExpression expression)
{
// It's not needed to wrap if none of the descendants return an observable
if (!expression.DescendantNodes().Any(n => (n.HasAnnotation <ResultIsObservableAnnotation>() && !n.HasAnnotation <ShouldBeObservableAnnotation>()) || n.HasAnnotation <ObservableUnwrapInvocationAnnotation>()))
{
return(expression.WithAnnotation(ShouldBeObservableAnnotation.Instance));
}
else if (expression.SatisfyResultCondition(n => n.HasAnnotation <ResultIsObservableAnnotation>()))
{
var arguments = new List <JsExpression>(2)
{
new JsFunctionExpression(
parameters: Enumerable.Empty <JsIdentifier>(),
bodyBlock: new JsBlockStatement(new JsReturnStatement(expression.WithAnnotation(ShouldBeObservableAnnotation.Instance)))
)
};
if (expression.SatisfyResultCondition(n => n.HasAnnotation <ResultIsObservableArrayAnnotation>()))
{
arguments.Add(new JsLiteral(true));
}
return(new JsIdentifierExpression("dotvvm").Member("evaluator").Member("wrapObservable").Invoke(arguments)
.WithAnnotation(ResultIsObservableAnnotation.Instance)
.WithAnnotation(ShouldBeObservableAnnotation.Instance));
}
else
{
return(new JsIdentifierExpression("ko").Member("pureComputed").Invoke(new JsFunctionExpression(
parameters: Enumerable.Empty <JsIdentifier>(),
bodyBlock: new JsBlockStatement(new JsReturnStatement(expression))
))
.WithAnnotation(ResultIsObservableAnnotation.Instance)
.WithAnnotation(ShouldBeObservableAnnotation.Instance));
}
}