//Property overriding taken from
//http://stackoverflow.com/questions/12143650/how-to-add-property-level-attribute-to-the-typedescriptor-at-runtime
private void OverrideProperty(Type type, string PropertyName, params Attribute[] attributes)
{
//Override the KeyValue type descriptors
// prepare our property overriding type descriptor
PropertyOverridingTypeDescriptor ctd = new PropertyOverridingTypeDescriptor(TypeDescriptor.GetProvider(type).GetTypeDescriptor(type));
// iterate through properies in the supplied object/type
foreach (System.ComponentModel.PropertyDescriptor pd in TypeDescriptor.GetProperties(typeof(KeyValue)))
{
// for every property that complies to our criteria
if (pd.Name == PropertyName)
{
// we first construct the custom PropertyDescriptor with the TypeDescriptor's
// built-in capabilities
System.ComponentModel.PropertyDescriptor pd2 =
TypeDescriptor.CreateProperty(
type, // or just _settings, if it's already a type
pd, // base property descriptor to which we want to add attributes
// The PropertyDescriptor which we'll get will just wrap that
// base one returning attributes we need.
attributes
// this method really can take as many attributes as you like,
// not just one
);
// and then we tell our new PropertyOverridingTypeDescriptor to override that property
ctd.OverrideProperty(pd2);
}
}
// then we add new descriptor provider that will return our descriptor istead of default
TypeDescriptor.AddProvider(new TypeDescriptorOverridingProvider(ctd), type);
}
public void WhenOnlyTheNamePropertyIsSetInDto_GivenEntityWithMultiplePropertiesSetIncludingTheName_ShouldReturnEntityWithOnlyTheNameChanged()
{
var entity = new Category()
{
Name = "entity name",
Description = "some description"
};
var dto = new CategoryDto()
{
Name = "updated name"
};
//Attributes are readonly - http://stackoverflow.com/questions/10046601/change-custom-attributes-parameter-at-runtime
// So we are going to try to replace the attribute with new instance.
//******************************
PropertyOverridingTypeDescriptor ctd = new PropertyOverridingTypeDescriptor(TypeDescriptor.GetProvider(dto).GetTypeDescriptor(dto));
PropertyDescriptor desriptionPorpertyDescriptor = ctd.GetProperties().Find("Description", true);
PropertyDescriptor pd2 =
TypeDescriptor.CreateProperty(
dto.GetType(),
desriptionPorpertyDescriptor, // base property descriptor to which we want to add attributes
// The PropertyDescriptor which we'll get will just wrap that
// base one returning attributes we need.
new Updated(false)
// this method really can take as many attributes as you like,
// not just one
);
// and then we tell our new PropertyOverridingTypeDescriptor to override that property
ctd.OverrideProperty(pd2);
// then we add new descriptor provider that will return our descriptor istead of default
TypeDescriptor.AddProvider(new TypeDescriptorOverridingProvider(ctd), dto);
//******************************
Category resultEntity = entity.Merge(dto);
// The name should be updated
Assert.AreEqual(dto.Name, resultEntity.Name);
// The description shouldn't be updated
Assert.NotNull(entity.Description);
Assert.AreEqual(entity.Description, resultEntity.Description);
}
public static void SetAttribute(string propName, params Attribute[] attr)
{
var _settings = Settings.Default;
PropertyOverridingTypeDescriptor ctd = new PropertyOverridingTypeDescriptor(TypeDescriptor.GetProvider(_settings).GetTypeDescriptor(_settings));
foreach (PropertyDescriptor pd in TypeDescriptor.GetProperties(_settings))
{
if (pd.Name == propName)
{
PropertyDescriptor pd2 = TypeDescriptor.CreateProperty(_settings.GetType(), pd, attr);
ctd.OverrideProperty(pd2);
}
}
TypeDescriptor.AddProvider(new TypeDescriptorOverridingProvider(ctd), _settings);
}
