/// <summary>
/// Propagates changes from model property to view-model property.
/// </summary>
/// <typeparam name="TModelResult">Model property type</typeparam>
/// <typeparam name="TViewModelResult">View-model property type</typeparam>
/// <param name="modelProperty">Model property</param>
/// <param name="viewModelProperty">View-model property</param>
protected virtual void AssociateProperties <TModelResult, TViewModelResult>
(Expression <Func <TModel, TModelResult> > modelProperty,
Expression <Func <TViewModel, TViewModelResult> > viewModelProperty)
{
// Convert expressions to a property names
string modelPropertyName = ((MemberExpression)modelProperty.Body).Member.Name;
string viewModelPropertyName = ((MemberExpression)viewModelProperty.Body).Member.Name;
// Get handlers
if (!assocPropsHandlers.ContainsKey(modelPropertyName))
{
assocPropsHandlers.Add(modelPropertyName, new PropertyDictionary());
}
var handlers = assocPropsHandlers[modelPropertyName];
// Propagate model to view-model property change
PropertyChangedEventHandler handler = (s, ea) =>
{
if (ea.PropertyName == modelPropertyName)
{
BindingHelper.InternalNotifyPropertyChanged(viewModelPropertyName,
this, base.propertyChanged);
}
};
// Add handler to property changed event
Model.PropertyChanged += handler;
// Add handler to handlers list
handlers.Add(viewModelPropertyName, handler);
}
/// <summary>
/// Copies property values from clone to original.
/// </summary>
public void EndEdit()
{
// Return if BeginEdit not called first
if (Copy == null)
{
return;
}
// Tranfer values from copy to original
Copy.CopyValuesTo(Original);
// Point entity to original
Model = Original;
// Clear copy
Copy = null;
// Notify IsEditing, IsDirty
BindingHelper.InternalNotifyPropertyChanged("IsEditing",
this, base.propertyChanged);
BindingHelper.InternalNotifyPropertyChanged("IsDirty",
this, base.propertyChanged);
// Post-processing
OnEndEdit();
}
/// <summary>
/// Caches a deep clone of the entity
/// </summary>
public void BeginEdit()
{
// Throw an exception if Entity not supplied
if (Model == null)
{
throw new InvalidOperationException("Entity must be set");
}
// Return if we're already editing
if (Copy != null)
{
return;
}
// Copy entity
Original = Model;
Copy = Model.Clone();
// Point entity to the copy
Model = Copy;
// Notify IsEditing, IsDirty
BindingHelper.InternalNotifyPropertyChanged("IsEditing",
this, base.propertyChanged);
BindingHelper.InternalNotifyPropertyChanged("IsDirty",
this, base.propertyChanged);
// Post-processing
OnBeginEdit();
}
private void InternalValidateProperty(string propertyName, object value)
{
var results = new List <ValidationResult>();
bool isValid = Validator.TryValidateProperty(value, new ValidationContext(this, null, null)
{
MemberName = propertyName
}, results);
if (isValid)
{
RemoveErrors(propertyName);
}
else
{
AddErrors(propertyName, results);
}
NotifyErrorsChanged(propertyName);
BindingHelper.InternalNotifyPropertyChanged("HasErrors", this, propertyChanged);
}
/// <summary>
/// Restores original
/// </summary>
public void CancelEdit()
{
// Return if BeginEdit not called first
if (Copy == null)
{
return;
}
// Point entity to original
Model = Original;
// Clear copy
Copy = null;
// Notify IsEditing, IsDirty
BindingHelper.InternalNotifyPropertyChanged("IsEditing",
this, base.propertyChanged);
BindingHelper.InternalNotifyPropertyChanged("IsDirty",
this, base.propertyChanged);
// Post-processing
OnCancelEdit();
}
