/// <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;
}
}
/// <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)));
}
}
}
/// <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) : "";
}
}
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>
/// 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>
/// Determines whether the rule should attach its condition to the given <see cref="ModelInstance"/>.
/// </summary>
/// <param name="root">The model instance to evaluate the rule for.</param>
/// <returns>A boolean value indicating whether the state of the given <see cref="ModelInstance"/> violates the rule.</returns>
protected override bool ConditionApplies(ModelInstance root)
{
if (RequiredValue != null)
{
return(root[Property] == null || !root[Property].Equals(RequiredValue));
}
else
{
return
(root[Property] == null ||
(Property is ModelReferenceProperty && Property.IsList && root.GetList((ModelReferenceProperty)Property).Count == 0));
}
}
/// <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>
/// Ensure the destination instance path is valid when nulls are encountered along the path.
/// </summary>
/// <param name="instance"></param>
/// <param name="property"></param>
/// <param name="index"></param>
bool EnsureDestinationInstance(ModelInstance instance, ModelReferenceProperty property, int index)
{
if (property.IsList)
{
ModelInstanceList list = instance.GetList(property);
for (int i = list.Count; i <= index; i++)
{
list.Add(property.PropertyType.Create());
}
}
else
{
instance.SetReference(property, property.PropertyType.Create());
}
return(true);
}
protected override bool ConditionApplies(ModelInstance root)
{
int value = root.GetList((ModelReferenceProperty)Property).Count;
if (Minimum > 0 && Maximum > 0)
{
return(Minimum.CompareTo(value) > 0 && Maximum.CompareTo(value) < 0);
}
else if (Minimum > 0)
{
return(Minimum.CompareTo(value) > 0);
}
else if (Maximum > 0)
{
return(Maximum.CompareTo(value) < 0);
}
else
{
return(false);
}
}
/// <summary>
/// Ensure the destination instance path is valid when nulls are encountered along the path.
/// </summary>
/// <param name="instance"></param>
/// <param name="property"></param>
/// <param name="index"></param>
bool EnsureDestinationInstance(ModelInstance instance, ModelReferenceProperty property, int index)
{
if (property.IsList)
{
ModelInstanceList list = instance.GetList(property);
for (int i = list.Count; i <= index; i++)
list.Add(property.PropertyType.Create());
}
else
instance.SetReference(property, property.PropertyType.Create());
return true;
}
protected override bool ConditionApplies(ModelInstance root)
{
int value = root.GetList((ModelReferenceProperty)Property).Count;
if (Minimum > 0 && Maximum > 0)
return Minimum.CompareTo(value) > 0 && Maximum.CompareTo(value) < 0;
else if (Minimum > 0)
return Minimum.CompareTo(value) > 0;
else if (Maximum > 0)
return Maximum.CompareTo(value) < 0;
else
return false;
}
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;
}
/// <summary>
/// Determines whether the rule should attach its condition to the given <see cref="ModelInstance"/>.
/// </summary>
/// <param name="root">The model instance to evaluate the rule for.</param>
/// <returns>A boolean value indicating whether the state of the given <see cref="ModelInstance"/> violates the rule.</returns>
protected override bool ConditionApplies(ModelInstance root)
{
if (RequiredValue != null)
return root[Property] == null || !root[Property].Equals(RequiredValue);
else
return
root[Property] == null ||
(Property is ModelReferenceProperty && Property.IsList && root.GetList((ModelReferenceProperty)Property).Count == 0);
}
protected override bool ConditionApplies(ModelInstance root)
{
var value = root[Property];
// Exit immediately if the target property has a value
if (RequiredValue == null && (value != null &&
(!(Property is ModelReferenceProperty) || !Property.IsList || root.GetList((ModelReferenceProperty)Property).Count > 0)))
{
return(false);
}
// If the required value is specified then the value must equal the required value
var requiredValueCondition = RequiredValue == null || !RequiredValue.Equals(value);
// Invoke the ModelExpression if it exists
if (RequiredExpression != null)
{
try
{
return((bool)RequiredExpression.Invoke(root) && requiredValueCondition);
}
catch
{
return(false);
}
}
// If the value to compare is null, then evaluate whether the compare source has a value
else if (CompareValue == null)
{
return((CompareOperator == CompareOperator.Equal ? !compareSource.HasValue(root) : compareSource.HasValue(root)) && requiredValueCondition);
}
// Otherwise, perform a comparison of the compare source relative to the compare value
bool?result = CompareRule.Compare(compareSource.GetValue(root), CompareOperator, CompareValue);
return(result.HasValue && result.Value && requiredValueCondition);
}
protected override bool ConditionApplies(ModelInstance root)
{
var value = root[Property];
// Exit immediately if the target property has a value
if (RequiredValue == null && (value != null &&
(!(Property is ModelReferenceProperty) || !Property.IsList || root.GetList((ModelReferenceProperty)Property).Count > 0)))
return false;
// If the required value is specified then the value must equal the required value
var requiredValueCondition = RequiredValue == null || !RequiredValue.Equals(value);
// Invoke the ModelExpression if it exists
if (RequiredExpression != null)
{
try
{
return (bool)RequiredExpression.Invoke(root) && requiredValueCondition;
}
catch
{
return false;
}
}
// If the value to compare is null, then evaluate whether the compare source has a value
else if (CompareValue == null)
return (CompareOperator == CompareOperator.Equal ? !compareSource.HasValue(root) : compareSource.HasValue(root)) && requiredValueCondition;
// Otherwise, perform a comparison of the compare source relative to the compare value
bool? result = CompareRule.Compare(compareSource.GetValue(root), CompareOperator, CompareValue);
return result.HasValue && result.Value && requiredValueCondition;
}
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));
}
}
}
