/// <summary>
/// Traces the computed property given by the trace expression.
/// </summary>
/// <param name="toTrace">The object to trace.</param>
/// <param name="expression">The member expression.</param>
/// <param name="traceMode">The trace mode to use.</param>
/// <typeparam name="TObject">The type of the object.</typeparam>
/// <typeparam name="TMember">The property or method of the object.</typeparam>
/// <exception cref="InvalidOperationException">When the provided expression is not a member expression.</exception>
public static void Trace <TObject, TMember>(this TObject toTrace, Expression <Func <TObject, TMember> > expression, TraceMode traceMode = TraceMode.Log)
{
if (expression is null)
{
throw new ArgumentNullException(nameof(expression));
}
var observableObject = ObservableObject.GetFromObject(toTrace);
if (observableObject == null)
{
throw new InvalidOperationException(Resources.CannotTraceNotObservable);
}
string key = expression.ExtractNameFromMemberExpression();
var observableValue = observableObject[key];
if (observableValue is IDerivation derivation)
{
derivation.Trace(traceMode);
return;
}
throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, Resources.ProvidedMemberNoDerivation, key));
}
/// <summary>
/// Gets the underlying atom from the IReactiveObject instance.
/// </summary>
/// <param name="reactiveObject">The reactive object to get the atom for.</param>
/// <returns>The IAtom instance to get.</returns>
/// <exception cref="ArgumentOutOfRangeException">Thrown when there is no atom provider internally.</exception>
public static IObservable GetObservable(this object reactiveObject)
{
if (reactiveObject is null)
{
throw new ArgumentNullException(nameof(reactiveObject));
}
var observableObject = ObservableObject.GetFromObject(reactiveObject);
if (observableObject != null)
{
return(((IAtomProvider)observableObject).Atom);
}
if (observableObject is IAtomProvider atomProvider)
{
return(atomProvider.Atom);
}
throw new ArgumentOutOfRangeException(nameof(reactiveObject));
}
/// <summary>
/// Gets the observable for a member of an object.
/// </summary>
/// <typeparam name="TObject">The type of the object.</typeparam>
/// <typeparam name="TMember">The type of the member.</typeparam>
/// <param name="target">The target object to get a property from.</param>
/// <param name="expression">The member expression.</param>
/// <returns>An atom for the member of an object.</returns>
public static IObservable GetObservable <TObject, TMember>(this TObject target, Expression <Func <TObject, TMember> > expression)
where TObject : class
{
if (target is null)
{
throw new ArgumentNullException(nameof(target));
}
if (expression is null)
{
throw new ArgumentNullException(nameof(expression));
}
var observableObject = ObservableObject.GetFromObject(target);
if (observableObject != null)
{
var name = expression.ExtractNameFromMemberExpression();
if (!string.IsNullOrEmpty(name))
{
if (observableObject.Has(name))
{
var value = observableObject[name];
return((IObservable)value);
}
}
}
var ex = expression.Compile();
var result = ex(target);
if (result is IAtomProvider atomProvider)
{
return(atomProvider.Atom);
}
throw new ArgumentOutOfRangeException(nameof(expression));
}