private bool IsBinaryOperatorEntityIsNullCheck(BinaryOperator binaryOperator)
{
return ((binaryOperator.Member == MethodNames.Equal) || (binaryOperator.Member == MethodNames.NotEqual)) &&
(((binaryOperator.RightOperand is Literal) && (((Literal)binaryOperator.RightOperand).Value == null)) ||
((binaryOperator.LeftOperand is Literal) && (((Literal)binaryOperator.LeftOperand).Value == null)));
}
private bool IsBinaryOperatorComplexEntityContrain(BinaryOperator binaryOperator)
{
return ((binaryOperator.Member == MethodNames.Or) || (binaryOperator.Member == MethodNames.And)) &&
((binaryOperator.LeftOperand is EntityConstrain) || (binaryOperator.RightOperand is EntityConstrain) ||
((binaryOperator.LeftOperand is BinaryOperator) && (IsBinaryOperatorComplexEntityContrain((BinaryOperator)binaryOperator.LeftOperand))) ||
((binaryOperator.RightOperand is BinaryOperator) && (IsBinaryOperatorComplexEntityContrain((BinaryOperator)binaryOperator.RightOperand))));
}
private void VisitEntityIsNullCheck(BinaryOperator binaryOperator)
{
if (binaryOperator.Member == MethodNames.Equal)
{
EntityConstrain entityConstrain;
_commandText.Append("NOT EXISTS {");
VisitComponent(_currentEntityAccessor.Peek().About);
_commandText.Append(" ");
if ((binaryOperator.RightOperand is Literal) && (((Literal)binaryOperator.RightOperand).Value == null))
{
entityConstrain = _currentEntityAccessor.Peek().Elements.OfType<EntityConstrain>().Where(item => item.Value == binaryOperator.LeftOperand).First();
VisitComponent(entityConstrain.Predicate);
_commandText.Append(" ");
VisitComponent(binaryOperator.LeftOperand);
}
else
{
entityConstrain = _currentEntityAccessor.Peek().Elements.OfType<EntityConstrain>().Where(item => item.Value == binaryOperator.RightOperand).First();
VisitComponent(entityConstrain.Predicate);
_commandText.Append(" ");
VisitComponent(binaryOperator.RightOperand);
}
_commandText.Append("}");
_visitedComponents.Remove(entityConstrain);
}
else
{
_cancelLast = true;
}
}
private void VisitComplexEntityContrain(BinaryOperator binaryOperator)
{
string operatorString;
switch (binaryOperator.Member)
{
case MethodNames.Or:
operatorString = "||";
break;
case MethodNames.And:
operatorString = "&&";
break;
default:
throw new NotImplementedException(String.Format("Binary operator '{0}' is not supported.", binaryOperator.Member));
}
switch (operatorString)
{
case "||":
{
_commandText.Append("EXISTS { ");
VisitComponent(binaryOperator.LeftOperand);
_commandText.Append(" } || EXISTS { ");
VisitComponent(binaryOperator.RightOperand);
_commandText.Append("} ");
break;
}
case "&&":
{
_commandText.Append("{ ");
VisitComponent(binaryOperator.LeftOperand);
VisitComponent(binaryOperator.RightOperand);
_commandText.Append("} ");
break;
}
}
}
/// <summary>Visit a binary operator.</summary>
/// <param name="binaryOperator">Binary operator to be visited.</param>
protected override void VisitBinaryOperator(BinaryOperator binaryOperator)
{
if (IsBinaryOperatorComplexEntityContrain(binaryOperator))
{
VisitComplexEntityContrain(binaryOperator);
}
else if (IsBinaryOperatorEntityIsNullCheck(binaryOperator))
{
VisitEntityIsNullCheck(binaryOperator);
}
else
{
string operatorString;
switch (binaryOperator.Member)
{
case MethodNames.Add:
operatorString = "+";
break;
case MethodNames.Substract:
operatorString = "-";
break;
case MethodNames.Multiply:
operatorString = "*";
break;
case MethodNames.Divide:
operatorString = "/";
break;
case MethodNames.Equal:
operatorString = "=";
break;
case MethodNames.GreaterThan:
operatorString = ">";
break;
case MethodNames.GreaterThanOrEqual:
operatorString = ">=";
break;
case MethodNames.LessThan:
operatorString = "<";
break;
case MethodNames.LessThanOrEqual:
operatorString = "<=";
break;
case MethodNames.NotEqual:
operatorString = "!=";
break;
case MethodNames.Or:
operatorString = "||";
break;
case MethodNames.And:
operatorString = "&&";
break;
default:
throw new NotImplementedException(String.Format("Binary operator '{0}' is not supported.", binaryOperator.Member));
}
VisitComponent(binaryOperator.LeftOperand);
bool leftOperandCanceled = _cancelLast;
_cancelLast = false;
int startIndex = _commandText.Length;
if (!leftOperandCanceled)
{
_commandText.AppendFormat(" {0} ", operatorString);
}
VisitComponent(binaryOperator.RightOperand);
bool rightOperandCanceled = _cancelLast;
_cancelLast = false;
int length = _commandText.Length - startIndex;
if (rightOperandCanceled)
{
_commandText = _commandText.Remove(startIndex, length);
}
_cancelLast = leftOperandCanceled && rightOperandCanceled;
}
}
/// <summary>Visit a binary operator.</summary> /// <param name="binaryOperator">Binary operator to be visited.</param> protected abstract void VisitBinaryOperator(BinaryOperator binaryOperator);
