/// <summary>
/// Unsubscribe from model object changes
/// </summary>
/// <param name="model">Model object to unsubscribe from</param>
private static void UnsubscribeFromModelObject(ModelObject model)
{
if (model == null)
{
return;
}
PropertyChangedEventHandler changeHandler = _propertyChangedHandlers[model];
if (changeHandler == null)
{
// Already unregistered - don't bother to continue
return;
}
model.PropertyChanged -= changeHandler;
_propertyChangedHandlers.Remove(model);
bool unregisterPropertyChanging = false;
foreach (PropertyInfo property in model.GetType().GetProperties())
{
object value = property.GetValue(model);
if (property.PropertyType.IsSubclassOf(typeof(ModelObject)))
{
if (value != null)
{
UnsubscribeFromModelObject((ModelObject)value);
}
unregisterPropertyChanging |= (property.SetMethod != null);
}
else if (ModelCollection.GetItemType(property.PropertyType, out Type itemType))
{
if (ModelGrowingCollection.TypeMatches(property.PropertyType))
{
UnsubscribeFromGrowingModelCollection(value);
}
else
{
UnsubscribeFromModelCollection(value, property.PropertyType.GetGenericArguments()[0]);
}
}
else if (property.PropertyType.IsGenericType && typeof(ModelDictionary <>) == property.PropertyType.GetGenericTypeDefinition())
{
UnsubscribeFromModelDictionary(value);
}
}
if (unregisterPropertyChanging)
{
// Same here - unregister the event handler only where required
model.PropertyChanging -= VariableModelObjectChanging;
}
}
/// <summary>
/// Subscribe to changes of the given model object
/// </summary>
/// <param name="model">Object to subscribe to</param>
/// <param name="path">Collection path</param>
private static void SubscribeToModelObject(ModelObject model, object[] path)
{
if (model == null)
{
return;
}
bool hasVariableModelObjects = false;
foreach (PropertyInfo property in model.GetType().GetProperties())
{
string propertyName = JsonNamingPolicy.CamelCase.ConvertName(property.Name);
object value = property.GetValue(model);
if (property.PropertyType.IsSubclassOf(typeof(ModelObject)))
{
if (value != null)
{
SubscribeToModelObject((ModelObject)value, AddToPath(path, propertyName));
}
hasVariableModelObjects |= (property.SetMethod != null);
}
else if (ModelCollection.GetItemType(property.PropertyType, out Type itemType))
{
if (ModelGrowingCollection.TypeMatches(property.PropertyType))
{
SubscribeToGrowingModelCollection(value, propertyName, path);
}
else
{
SubscribeToModelCollection(value, itemType, propertyName, path);
}
}
else if (property.PropertyType.IsGenericType && typeof(ModelDictionary <>) == property.PropertyType.GetGenericTypeDefinition())
{
SubscribeToModelDictionary(value, AddToPath(path, propertyName));
}
}
PropertyChangedEventHandler changeHandler = PropertyChanged(hasVariableModelObjects, path);
model.PropertyChanged += changeHandler;
_propertyChangedHandlers[model] = changeHandler;
if (hasVariableModelObjects)
{
// This is barely needed so only register it where it is actually required.
// It makes sure that events are removed again when a ModelObject instance is replaced
model.PropertyChanging += VariableModelObjectChanging;
}
}
