private void SubscribeListeners(Expression propertyExpression)
{
var propNameStack = new Stack <PropertyInfo>();
while (propertyExpression is MemberExpression temp) // Gets the root of the property chain.
{
propertyExpression = temp.Expression;
propNameStack.Push(temp.Member as PropertyInfo); // Records the member info as property info
}
if (!(propertyExpression is ConstantExpression constantExpression))
{
throw new NotSupportedException("Operation not supported for the given expression type. " +
"Only MemberExpression and ConstantExpression are currently supported.");
}
var propObserverNodeRoot = new PropertyObserverNode(propNameStack.Pop(), _action);
PropertyObserverNode previousNode = propObserverNodeRoot;
foreach (var propName in propNameStack) // Create a node chain that corresponds to the property chain.
{
var currentNode = new PropertyObserverNode(propName, _action);
previousNode.Next = currentNode;
previousNode = currentNode;
}
object propOwnerObject = constantExpression.Value;
if (!(propOwnerObject is INotifyPropertyChanged inpcObject))
{
throw new InvalidOperationException("Trying to subscribe PropertyChanged listener in object that " +
$"owns '{propObserverNodeRoot.PropertyInfo.Name}' property, but the object does not implements INotifyPropertyChanged.");
}
propObserverNodeRoot.SubscribeListenerFor(inpcObject);
}
private void Start()
{
PropertyObserverNode.Observes(_propertyExpression, _action, this);
}
