public IModelPropertySource GetSource(ModelInstance root, Func <ModelInstance, ModelReferenceProperty, int, bool> whenNull, Action <ModelInstance, ModelReferenceProperty, int, ModelInstance> whenNotNull)
{
// Return the source type for static paths
if (IsStatic)
{
return(ModelContext.Current.GetModelType(SourceType));
}
//walk the path performing whenNull if an entity is null
//if an entity is null and whenNull returns false
//then exit out of SetValue returning false
foreach (SourceStep step in this.steps.Take(this.steps.Length - 1))
{
ModelReferenceProperty stepProp = (ModelReferenceProperty)step.DeclaringType.Properties[step.Property];
if (stepProp.IsList)
{
ModelInstanceList list = root.GetList(stepProp);
if (list.Count < step.Index + 1 && (whenNull == null || !whenNull(root, stepProp, step.Index)))
{
return(null);
}
var item = list[step.Index];
if (whenNotNull != null)
{
whenNotNull(root, stepProp, step.Index, item);
}
root = item;
}
else
{
if (root.GetReference(stepProp) == null && (whenNull == null || !whenNull(root, stepProp, step.Index)))
{
return(null);
}
else
{
//advance to the next step in the chain.
var child = root.GetReference(step.Property);
if (whenNotNull != null)
{
whenNotNull(root, stepProp, step.Index, child);
}
root = child;
}
}
}
return(root);
}
/// <summary>
/// Enumerates over the set of instances represented by the current step.
/// </summary>
/// <param name="instance"></param>
/// <returns></returns>
public IEnumerable<ModelInstance> GetInstances(ModelInstance instance)
{
// Exit immediately if the property is not valid for the specified instance
if (!DeclaringType.IsInstanceOfType(instance))
throw new ArgumentException("The current property is not valid for the specified instance.");
// Return each instance exposed by a list property
if (IsList)
{
ModelInstanceList children = instance.GetList(this);
if (children != null)
{
foreach (ModelInstance child in children)
yield return child;
}
}
// Return the instance exposed by a reference property
else
{
ModelInstance child = instance.GetReference(this);
if (child != null)
yield return child;
}
}
/// <summary>
/// Enumerates over the set of instances represented by the current step.
/// </summary>
/// <param name="instance"></param>
/// <returns></returns>
public IEnumerable<ModelInstance> GetInstances(ModelInstance instance)
{
// Stop loading if the step is null or represents a value
if (Property is ModelValueProperty || !((ModelReferenceProperty)Property).DeclaringType.IsInstanceOfType(instance))
yield break;
// Cast the property to the correct type
var reference = (ModelReferenceProperty)Property;
// Return each instance exposed by a list property
if (reference.IsList)
{
ModelInstanceList children = instance.GetList(reference);
if (children != null)
{
foreach (ModelInstance child in instance.GetList(reference))
{
if (Filter == null || Filter.IsInstanceOfType(child))
yield return child;
}
}
}
// Return the instance exposed by a reference property
else
{
ModelInstance child = instance.GetReference(reference);
if (child != null && (Filter == null || Filter.IsInstanceOfType(child)))
yield return child;
}
}
/// <summary>
/// Enumerates over the set of instances represented by the current step.
/// </summary>
/// <param name="instance"></param>
/// <returns></returns>
public IEnumerable <ModelInstance> GetInstances(ModelInstance instance)
{
// Exit immediately if the property is not valid for the specified instance
if (!DeclaringType.IsInstanceOfType(instance))
{
throw new ArgumentException("The current property is not valid for the specified instance.");
}
// Return each instance exposed by a list property
if (IsList)
{
ModelInstanceList children = instance.GetList(this);
if (children != null)
{
foreach (ModelInstance child in children)
{
yield return(child);
}
}
}
// Return the instance exposed by a reference property
else
{
ModelInstance child = instance.GetReference(this);
if (child != null)
{
yield return(child);
}
}
}
protected override bool ConditionApplies(ModelInstance root)
{
// Get the allowed values
var allowedValues = GetAllowedValues(root);
// Always consider as valid when there are no allowed values
if (allowedValues == null)
{
return(false);
}
// Value properties
if (Property is ModelValueProperty)
{
// List
if (Property.IsList)
{
// Get the current property value
var values = root.GetValue((ModelValueProperty)Property) as IEnumerable;
// Determine whether the property value is in the list of allowed values
return(!(values == null || values.Cast <object>().All(value => allowedValues.Contains(value))));
}
// Value
else
{
// Get the current property value
var value = root.GetValue((ModelValueProperty)Property);
// Determine whether the property value is in the list of allowed values
return(!(value == null || allowedValues.Contains(value)));
}
}
// Reference properties
else
{
// List Property
if (Property.IsList)
{
// Get the current property value
ModelInstanceList values = root.GetList((ModelReferenceProperty)Property);
// Determine whether the property value is in the list of allowed values
return(!(values == null || values.All(value => allowedValues.Contains(value))));
}
// Reference Property
else
{
// Get the current property value
ModelInstance value = root.GetReference((ModelReferenceProperty)Property);
// Determine whether the property value is in the list of allowed values
return(!(value == null || allowedValues.Contains(value)));
}
}
}
protected internal override void OnInvoke(ModelInstance root, ModelEvent modelEvent)
{
// Marks the instance as pending delete if an owner property is set to null.
if (Property is ModelReferenceProperty && !Property.IsList)
{
root.IsPendingDelete = root.GetReference((ModelReferenceProperty)Property) == null;
}
}
/// <summary>
/// Gets the formatted value of the property for the specified instance.
/// </summary>
protected internal override string GetFormattedValue(ModelInstance instance, string format, IFormatProvider provider)
{
if (IsList)
return instance.GetList(this).ToString(format ?? Format, provider);
else
{
var reference = instance.GetReference(this);
return reference != null ? reference.ToString(format ?? Format, provider) : "";
}
}
/// <summary>
/// Gets the formatted value of the property for the specified instance.
/// </summary>
protected internal override string GetFormattedValue(ModelInstance instance, string format, IFormatProvider provider)
{
if (IsList)
{
return(instance.GetList(this).ToString(format ?? Format, provider));
}
else
{
var reference = instance.GetReference(this);
return(reference != null?reference.ToString(format ?? Format, provider) : "");
}
}
/// <summary>
/// Enumerates over the set of instances represented by the current step.
/// </summary>
/// <param name="instance"></param>
/// <returns></returns>
public IEnumerable <ModelInstance> GetInstances(ModelInstance instance)
{
// Stop loading if the step is null or represents a value
if (Property is ModelValueProperty || !((ModelReferenceProperty)Property).DeclaringType.IsInstanceOfType(instance))
{
yield break;
}
// Cast the property to the correct type
var reference = (ModelReferenceProperty)Property;
// Return each instance exposed by a list property
if (reference.IsList)
{
ModelInstanceList children = instance.GetList(reference);
if (children != null)
{
foreach (ModelInstance child in instance.GetList(reference))
{
if (Filter == null || Filter.IsInstanceOfType(child))
{
yield return(child);
}
}
}
}
// Return the instance exposed by a reference property
else
{
ModelInstance child = instance.GetReference(reference);
if (child != null && (Filter == null || Filter.IsInstanceOfType(child)))
{
yield return(child);
}
}
}
public IModelPropertySource GetSource(ModelInstance root, Func<ModelInstance, ModelReferenceProperty, int, bool> whenNull)
{
// Return the source type for static paths
if (IsStatic)
return ModelContext.Current.GetModelType(SourceType);
//walk the path performing whenNull if an entity is null
//if an entity is null and whenNull returns false
//then exit out of SetValue returning false
foreach (SourceStep step in this.steps.Take(this.steps.Length - 1))
{
ModelReferenceProperty stepProp = (ModelReferenceProperty)ModelContext.Current.GetModelType(step.DeclaringType).Properties[step.Property];
if (stepProp.IsList)
{
ModelInstanceList list = root.GetList(stepProp);
if (list.Count < step.Index + 1 && !whenNull(root, stepProp, step.Index))
return null;
root = list[step.Index];
}
else
{
if (root.GetReference(stepProp) == null && !whenNull(root, stepProp, step.Index))
return null;
else
{
//advance to the next step in the chain.
root = root.GetReference(step.Property);
}
}
}
return root;
}
protected internal override void OnInvoke(ModelInstance root, ModelEvent modelEvent)
{
// Marks the instance as pending delete if an owner property is set to null.
if (Property is ModelReferenceProperty && !Property.IsList)
root.IsPendingDelete = root.GetReference((ModelReferenceProperty)Property) == null;
}
protected override bool ConditionApplies(ModelInstance root)
{
// Get the allowed values
var allowedValues = GetAllowedValues(root);
// Always consider as valid when there are no allowed values
if (allowedValues == null)
return false;
// Value properties
if (Property is ModelValueProperty)
{
// List
if (Property.IsList)
{
// Get the current property value
var values = root.GetValue((ModelValueProperty)Property) as IEnumerable;
// Determine whether the property value is in the list of allowed values
return !(values == null || values.Cast<object>().All(value => allowedValues.Contains(value)));
}
// Value
else
{
// Get the current property value
var value = root.GetValue((ModelValueProperty)Property);
// Determine whether the property value is in the list of allowed values
return !(value == null || allowedValues.Contains(value));
}
}
// Reference properties
else
{
// List Property
if (Property.IsList)
{
// Get the current property value
ModelInstanceList values = root.GetList((ModelReferenceProperty)Property);
// Determine whether the property value is in the list of allowed values
return !(values == null || values.All(value => allowedValues.Contains(value)));
}
// Reference Property
else
{
// Get the current property value
ModelInstance value = root.GetReference((ModelReferenceProperty)Property);
// Determine whether the property value is in the list of allowed values
return !(value == null || allowedValues.Contains(value));
}
}
}
