/// <summary>
/// Examines the type of the bound object and initializes all neccessary structures
/// that are needed before binding can start. This methods to be called once for
/// each type passed as <paramref name="target"/> (not for each object of that type).
/// </summary>
/// <param name="target">bound object</param>
/// <param name="sourceType">Type of binding (model/view helper).</param>
private void PrepareBindingTo(IBindable target, EBindingSourceType sourceType)
{
if (sourceType == EBindingSourceType.Model)
{
PropertyInfo modelProperty = FindFieldByAttribute(Type, typeof(ModelElementAttribute));
ModelElementType = modelProperty.GetValue(target, null).GetType();
if (ModelElementType == null)
{
throw new InvalidOperationException(string.Format("Model property for type {0} is not assigned or the property is not marked with ModelElementAttribute", Type));
}
if (!initializationInProgress)
{
Debug.WriteLine("Model binding for type " + target.GetType().Name + " with model type " + ModelElementType.Name);
}
ModelSourceGetter = DynamicMethodCompiler.CreateGetHandler(ModelElementType, modelProperty);
CreateBindingFunctions(sourceType, ModelElementType);
}
if (sourceType == EBindingSourceType.View)
{
PropertyInfo viewHelperProperty = FindFieldByAttribute(Type, typeof(ViewHelperElementAttribute));
ViewHelperType = viewHelperProperty.GetValue(target, null).GetType();
if (ViewHelperType == null)
{
throw new InvalidOperationException(string.Format("ViewHelper for type {0} is not assigned or the property is not marked with ViewHelperElementAttribute", Type));
}
if (!initializationInProgress)
{
Debug.WriteLine("View binding for type " + target.GetType().Name + " with view type " + ViewHelperType.Name);
}
ViewSourceGetter = DynamicMethodCompiler.CreateGetHandler(ViewHelperType, viewHelperProperty);
CreateBindingFunctions(sourceType, ViewHelperType);
}
}
/// <summary>
/// Starts bindings to properties of model element
/// or view helper of the object <paramref name="target"/>.
/// </summary>
/// <param name="target">The bound object</param>
/// <param name="sourceType">Type of binding (model/view helper).</param>
/// <seealso cref="ModelElementAttribute"/>
/// <seealso cref="ViewHelperElementAttribute"/>
public void StartBindings(IBindable target, EBindingSourceType sourceType)
{
if (initializationInProgress)
{
lock (initializationLock) { }
}
bool isReady = false;
if (sourceType == EBindingSourceType.Model && ModelSourceGetter != null)
{
isReady = true;
}
if (sourceType == EBindingSourceType.View && ViewSourceGetter != null)
{
isReady = true;
}
if (!isReady)
{
PrepareBindingTo(target, sourceType);
}
if (!initializationInProgress)
{
BindingCollection getterCollection = (sourceType == EBindingSourceType.Model) ? ModelGetterCollection : ViewGetterCollection;
foreach (string key in getterCollection.Keys)
{
UpdateValue(target, key, sourceType);
}
}
}
/// <summary>
/// Creates the binding functions (fills <see cref="ViewSetterCollection"/> and
/// <see cref="ViewGetterCollection"/> or <see cref="ModelSetterCollection"/> and
/// <see cref="ModelGetterCollection"/> with correct handlers). The handlers are
/// dynamically compiled.
/// </summary>
/// <param name="sourceType">Type of the source to bound to</param>
/// <param name="boundType">Type of the bound object</param>
private void CreateBindingFunctions(EBindingSourceType sourceType, Type boundType)
{
if (sourceType == EBindingSourceType.View)
{
foreach (ViewHelperPropertyMappingAttribute attribute in ViewMappingDeclarations)
{
if (!initializationInProgress)
{
Debug.WriteLine("View binding: " + attribute.SourcePropertyName + " -> " + attribute.declaringProperty.Name);
}
PropertyInfo sourceProp = boundType.GetProperty(attribute.SourcePropertyName);
ViewGetterCollection[sourceProp.Name] =
DynamicMethodCompiler.CreateGetHandler(boundType, sourceProp);
ViewSetterCollection[sourceProp.Name] =
DynamicMethodCompiler.CreateSetHandler(Type, attribute.declaringProperty);
}
}
if (sourceType == EBindingSourceType.Model)
{
foreach (ModelPropertyMappingAttribute attribute in ModelMappingDeclarations)
{
if (!initializationInProgress)
{
Debug.WriteLine("Model binding: " + attribute.SourcePropertyName + " -> " + attribute.declaringProperty.Name);
}
PropertyInfo sourceProp = boundType.GetProperty(attribute.SourcePropertyName);
ModelGetterCollection[sourceProp.Name] =
DynamicMethodCompiler.CreateGetHandler(boundType, sourceProp);
ModelSetterCollection[sourceProp.Name] =
DynamicMethodCompiler.CreateSetHandler(Type, attribute.declaringProperty);
}
}
}
/// <summary>
/// Updates the bound value of the bound property of <paramref name="boundObject"/>
/// when value of <paramref name="property"/> is changed in the binding source.
/// </summary>
/// <param name="boundObject">The bound object</param>
/// <param name="property">The property that changed in model or viewhelper </param>
/// <param name="sourceType">Type of binding (model/view helper).</param>
private void UpdateValue(IBindable boundObject, string property, EBindingSourceType sourceType)
{
if (sourceType == EBindingSourceType.Model && ModelGetterCollection.ContainsKey(property))
{
object value = ((GetHandler)ModelGetterCollection[property])(ModelSourceGetter(boundObject));
((SetHandler)ModelSetterCollection[property])(boundObject, value);
}
if (sourceType == EBindingSourceType.View && ViewGetterCollection.ContainsKey(property))
{
object value = ((GetHandler)ViewGetterCollection[property])(ViewSourceGetter(boundObject));
((SetHandler)ViewSetterCollection[property])(boundObject, value);
}
}
/// <summary>
/// Suspends the binding for the object <paramref name="target"/>.
/// </summary>
/// <param name="target">The bound object</param>
/// <param name="sourceType">Type of binding (model/view helper).</param>
public void CloseBindings(IBindable target, EBindingSourceType sourceType)
{
if (sourceType == EBindingSourceType.View)
{
if (ViewUpdaters.ContainsKey(target))
{
((INotifyPropertyChanged)ViewSourceGetter(target)).PropertyChanged -=
(PropertyChangedEventHandler)ViewUpdaters[target];
ViewUpdaters.Remove(target);
}
}
else
{
if (ModelUpdaters.ContainsKey(target))
{
((INotifyPropertyChanged)ModelSourceGetter(target)).PropertyChanged -=
(PropertyChangedEventHandler)ModelUpdaters[target];
ModelUpdaters.Remove(target);
}
}
}
