/// <summary>
/// Tests whether we need to generate the GetEntityState helper method. We do for POCO types.
/// If we determine we need to generate that helper, this method generates it and adds it to
/// the list of helper methods that will be appended to the generated code.
/// </summary>
/// <param name="codeGenContext">The context in which we are generating code.</param>
/// <param name="businessLogicClass">The class containing the generated code.</param>
/// <param name="entity">The entity that we need to test to determine whether the helper is needed.</param>
/// <returns><c>true</c> means the helper should be used.</returns>
private static bool GenerateGetEntityStateIfNecessary(CodeGenContext codeGenContext, CodeTypeDeclaration businessLogicClass, BusinessLogicEntity entity)
{
if (typeof(EntityObject).IsAssignableFrom(entity.ClrType))
{
return(false);
}
BusinessLogicContext.GenerateHelperMemberIfNecessary(codeGenContext, businessLogicClass, LinqToEntitiesContext.GetEntityStateHelperMethodName, () =>
{
return(LinqToEntitiesContext.GenerateGetEntityState(codeGenContext, businessLogicClass));
});
return(true);
}
/// <summary>
/// Generates the delete domain operation entry
/// </summary>
/// <param name="codeGenContext">The context to use</param>
/// <param name="businessLogicClass">The business logic class into which to generate it</param>
/// <param name="entity">The entity for which to generate the method</param>
protected override void GenerateDeleteMethod(CodeGenContext codeGenContext, CodeTypeDeclaration businessLogicClass, BusinessLogicEntity entity)
{
string parameterName = CodeGenUtilities.MakeLegalParameterName(entity.Name);
// public void Delete$EntityName$($entityType$ $entityName$)
CodeMemberMethod method = new CodeMemberMethod();
businessLogicClass.Members.Add(method);
//LinqToEntitiesEntity efEntity = (LinqToEntitiesEntity)entity;
method.Name = "Delete" + CodeGenUtilities.MakeLegalEntityName(entity.Name);
method.Attributes = MemberAttributes.Public | MemberAttributes.Final; // final needed to prevent virtual
// parameter declaration
method.Parameters.Add(new CodeParameterDeclarationExpression(entity.ClrType.Name, parameterName));
// if ($entity$.EntityState != EntityState.Detached)
// {
// ObjectContext.ObjectStateManager.ChangeObjectState($entity$, EntityState.Deleted);
// }
// else
// {
// ObjectContext.Products.Attach($entity$);
// ObjectContext.Products.DeleteObject($entity$);
// }
//
// In the case of POCO objects, we use "this.GetEntityState(entity)"
// rather than referring to the entity's EntityState property
LinqToEntitiesEntity efEntity = (LinqToEntitiesEntity)entity;
CodeArgumentReferenceExpression entityExpr = new CodeArgumentReferenceExpression(parameterName);
// If this is a POCO class, we need to generate a call to a helper method to get
// the EntityState, otherwise we can directly de-reference it on the entity
// If this entity does not have an EntityState member, we need to use a helper method instead.
// This call tells us whether we need this helper and, if so, generates it.
bool useGetEntityStateHelper = LinqToEntitiesContext.GenerateGetEntityStateIfNecessary(codeGenContext, businessLogicClass, entity);
CodeExpression getEntityStateExpr;
if (useGetEntityStateHelper)
{
// this.GetEntityState($entity$)...
getEntityStateExpr = new CodeMethodInvokeExpression(new CodeThisReferenceExpression(), LinqToEntitiesContext.GetEntityStateHelperMethodName, entityExpr);
}
else
{
// $entity$.EntityState...
getEntityStateExpr = new CodePropertyReferenceExpression(entityExpr, LinqToEntitiesContext.EntityStatePropertyName);
}
CodeExpression contextRef = new CodePropertyReferenceExpression(new CodeThisReferenceExpression(), "ObjectContext");
CodePropertyReferenceExpression objectSetRef = new CodePropertyReferenceExpression(contextRef, efEntity.DefaultObjectSetName);
CodeFieldReferenceExpression detachedStateRef = new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(typeof(EntityState).Name), Enum.GetName(typeof(EntityState), EntityState.Detached));
CodeExpression equalTest = CodeGenUtilities.MakeNotEqual(typeof(EntityState), getEntityStateExpr, detachedStateRef, codeGenContext.IsCSharp);
CodeFieldReferenceExpression deletedStateRef = new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(typeof(EntityState).Name), Enum.GetName(typeof(EntityState), EntityState.Deleted));
CodePropertyReferenceExpression objectStateMgrRef = new CodePropertyReferenceExpression(contextRef, "ObjectStateManager");
CodeMethodInvokeExpression changeStateExpr = new CodeMethodInvokeExpression(new CodeMethodReferenceExpression(objectStateMgrRef, "ChangeObjectState"), entityExpr, deletedStateRef);
CodeStatement[] trueStatements = new CodeStatement[] { new CodeExpressionStatement(changeStateExpr) };
CodeMethodInvokeExpression attachCall = new CodeMethodInvokeExpression(objectSetRef, "Attach", entityExpr);
CodeMethodInvokeExpression deleteCall = new CodeMethodInvokeExpression(objectSetRef, "DeleteObject", entityExpr);
CodeStatement[] falseStatements = new CodeStatement[] { new CodeExpressionStatement(attachCall), new CodeExpressionStatement(deleteCall) };
CodeConditionStatement ifStmt = new CodeConditionStatement(equalTest, trueStatements, falseStatements);
method.Statements.Add(ifStmt);
}