/// <summary>
///
/// </summary>
/// <param name="e"></param>
protected virtual void OnGetValue(ValueTranslationEventArgs e)
{
if (Getting != null)
{
Getting(this, e);
}
}
protected override void OnSetValue(ValueTranslationEventArgs e)
{
ReferenceEntityT refEntity = (ReferenceEntityT)e.Input;
if (refEntity == null)
{
e.Output = IdentityProperty.EmptyValue;
// Remove any reference in case it's still there
if (e.Entity.References.ContainsKey(this))
{
e.Entity.References.Remove(this);
}
}
else
{
e.Output = IdentityProperty.GetValue(refEntity);
e.Entity.References[this] = refEntity;
}
}
/*=========================*/
#endregion
#region Internal Methods
/*=========================*/
protected override void OnGetValue(ValueTranslationEventArgs e)
{
// Get the raw reference ID
ReferenceIdentityT refID = (ReferenceIdentityT)e.Input;
if (refID.Equals(IdentityProperty.EmptyValue))
{
// Empty ID means we return null value
e.Output = null;
// Remove any reference in case it's still there
if (e.Entity.References.ContainsKey(this))
{
e.Entity.References.Remove(this);
}
}
else
{
ReferenceEntityT refEntity = (ReferenceEntityT)e.Entity.References[this];
if (refEntity == null || !IdentityProperty.GetValue(refEntity).Equals(refID))
{
// Raise event for retrieving the entity
ValueTranslationEventArgs e2 = new ValueTranslationEventArgs(e.Entity, this);
e2.Input = refID;
if (ReferenceEntityRequired != null)
{
ReferenceEntityRequired(this, e2);
}
refEntity = (ReferenceEntityT)e2.Output;
e.Entity.References[this] = refEntity;
}
e.Output = refEntity;
}
base.OnGetValue(e);
}
/*=========================*/
#endregion
#region Public Methods
/*=========================*/
/// <summary>
///
/// </summary>
/// <param name="parent"></param>
/// <returns></returns>
public ValueT GetValue(EntityT parent)
{
if (parent == null)
{
throw new ArgumentNullException("parent");
}
// Try to retrieve current value, assign empty value if not
object input;
if (!parent.Values.TryGetValue(this, out input))
{
input = this.EmptyValue;
}
ValueTranslationEventArgs e = new ValueTranslationEventArgs(parent, this);
e.Input = input;
e.Output = input is ValueT ? input : this.DefaultValue;
OnGetValue(e);
return((ValueT)e.Output);
}
/// <summary>
///
/// </summary>
/// <param name="parent"></param>
/// <param name="value"></param>
public void SetValue(EntityT parent, ValueT value)
{
if (parent.DataState == EntityDataState.Deleted)
{
throw new InvalidOperationException("Cannot modify the value of an entity marked for deletion.");
}
// Validate the value and raise exception if necessary
string message;
// EXCEPTION:
if (!Validate(parent, value, out message))
{
throw new Exception(message);
}
// TODO: get last value without reinvoking GetValue
ValueT previouslyAppliedVal = GetValue(parent);
ValueTranslationEventArgs e = new ValueTranslationEventArgs(parent, this);
e.Input = value;
e.Output = value;
OnSetValue(e);
if (e.Cancel)
{
return;
}
// TODO: Dependency notifications
if (e.Output == null && previouslyAppliedVal == null)
{
return;
}
if (e.Output != null && e.Output.Equals(previouslyAppliedVal))
{
return;
}
// Apply value
parent.Values[this] = e.Output;
// Change data state to Modified if it was unchanged
if (parent.DataState == EntityDataState.Unchanged)
{
parent.DataState = EntityDataState.Modified;
}
// Raise events
if (ValueChanged != null)
{
ValueChanged(this, new ValueChangedEventArgs(parent, this, previouslyAppliedVal, value));
}
if (parent.HasPropertyChangedHandlers)
{
parent.OnPropertyChanged(new PropertyChangedEventArgs(this.InlineName));
}
}
