Imports NHibernate
Imports NHibernate.UserTypes
''' <summary>
''' Generic class for implementing NHibernate's <see cref="IUserType">IUserType</see> for a value type.
''' </summary>
''' <typeparam name="T">Value type</typeparam>
''' <remarks>The value type's <see cref="System.ComponentModel.TypeConverter">TypeConverter</see> is used for conversion</remarks>
Public MustInherit Class ValueConverterUserType(Of T As Structure)
Implements IUserType
Protected Converter As ComponentModel.TypeConverter = ComponentModel.TypeDescriptor.GetConverter(GetType(T))
''' <summary>
''' Reconstruct an object from the cacheable representation.
''' </summary>
''' <param name="cached"></param>
''' <param name="owner"></param>
''' <returns></returns>
''' <remarks>At the very least this method should perform a deep copy if the type is mutable. (optional operation)</remarks>
Public Function Assemble(ByVal cached As Object, ByVal owner As Object) As Object Implements NHibernate.UserTypes.IUserType.Assemble
Return DeepCopy(cached)
End Function
''' <summary>
''' Return a deep copy of the persistent state, stopping at entities and at collections.
''' </summary>
''' <param name="value"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Function DeepCopy(ByVal value As Object) As Object Implements NHibernate.UserTypes.IUserType.DeepCopy
Return value
End Function
''' <summary>
''' Transform the object into its cacheable representation.
''' </summary>
''' <param name="value"></param>
''' <returns></returns>
''' <remarks>At the very least this method should perform a deep copy if the type is mutable.
''' That may not be enough for some implementations, however; for example, associations must be cached as identifier values. (optional operation)</remarks>
Public Function Disassemble(ByVal value As Object) As Object Implements NHibernate.UserTypes.IUserType.Disassemble
Return DeepCopy(value)
End Function
''' <summary>
''' Compare two instances of the class mapped by this type for persistent "equality" ie. equality of persistent state
''' </summary>
''' <param name="x"></param>
''' <param name="y"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shadows Function Equals(ByVal x As Object, ByVal y As Object) As Boolean Implements NHibernate.UserTypes.IUserType.Equals
Return x.Equals(y)
End Function
''' <summary>
''' Get a hashcode for the instance, consistent with persistence "equality"
''' </summary>
''' <param name="x"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shadows Function GetHashCode(ByVal x As Object) As Integer Implements NHibernate.UserTypes.IUserType.GetHashCode
Return x.GetHashCode()
End Function
''' <summary>
''' Are objects of this type mutable?
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public ReadOnly Property IsMutable() As Boolean Implements NHibernate.UserTypes.IUserType.IsMutable
Get
Return False
End Get
End Property
''' <summary>
''' Retrieve an instance of the mapped class from an <see cref="IDataReader">IDataReader</see>.
''' </summary>
''' <param name="rs">IDataReader</param>
''' <param name="names">Column names</param>
''' <param name="owner">The containing entity</param>
''' <returns></returns>
''' <remarks></remarks>
Public Function NullSafeGet(ByVal rs As System.Data.IDataReader, ByVal names() As String, ByVal owner As Object) As Object Implements NHibernate.UserTypes.IUserType.NullSafeGet
Dim obj As Object = NHibernateUtil.String.NullSafeGet(rs, names)
Dim s As String = CStr(obj)
Return Converter.ConvertFromString(s)
End Function
''' <summary>
''' Write an instance of the mapped class to a prepared statement.
''' </summary>
''' <param name="cmd">an IDbCommand</param>
''' <param name="value">the object to write</param>
''' <param name="index">command parameter index</param>
''' <remarks>Implementors should handle possibility of null values. A multi-column type should be written to parameters starting from index.</remarks>
Public Sub NullSafeSet(ByVal cmd As System.Data.IDbCommand, ByVal value As Object, ByVal index As Integer) Implements NHibernate.UserTypes.IUserType.NullSafeSet
Dim NativeValue As String = Converter.ConvertToString(value)
NHibernateUtil.String.NullSafeSet(cmd, NativeValue, index)
End Sub
''' <summary>
''' During merge, replace the existing (target) value in the entity we are merging to with a new (original) value from the detached entity we are merging.
''' </summary>
''' <param name="original">the value from the detached entity being merged</param>
''' <param name="target">the value in the managed entity</param>
''' <param name="owner">the managed entity</param>
''' <returns>the value to be merged</returns>
''' <remarks>For immutable objects, or null values, it is safe to simply return the first parameter.
''' For mutable objects, it is safe to return a copy of the first parameter.
''' For objects with component values, it might make sense to recursively replace component values.</remarks>
Public Function Replace(ByVal original As Object, ByVal target As Object, ByVal owner As Object) As Object Implements NHibernate.UserTypes.IUserType.Replace
Return original
End Function
''' <summary>
''' The type returned by NullSafeGet()
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public ReadOnly Property ReturnedType() As System.Type Implements NHibernate.UserTypes.IUserType.ReturnedType
Get
Return GetType(T)
End Get
End Property
''' <summary>
''' The SQL types for the columns mapped by this type.
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public MustOverride ReadOnly Property SqlTypes() As NHibernate.SqlTypes.SqlType() Implements NHibernate.UserTypes.IUserType.SqlTypes
End Class
