protected object ResolveNodeValue(ResolveNodeContext nodeContext)
{
if (nodeContext.Node is QConst)
{
return(QConstResolver != null?QConstResolver(nodeContext) : ((QConst)nodeContext.Node).Value);
}
if (nodeContext.Node is QField)
{
return(QFieldResolver != null?QFieldResolver(nodeContext) : nodeContext.Context[((QField)nodeContext.Node).Name]);
}
throw new Exception("Cannot resolve value node type: " + nodeContext.Node.GetType().ToString());
}
protected bool EvaluateInternal(IDictionary context, QueryNode node)
{
if (node is QueryConditionNode)
{
var condNode = (QueryConditionNode)node;
IQueryValue lValue = condNode.LValue;
IQueryValue rValue = condNode.RValue;
bool negate = (condNode.Condition & Conditions.Not) == Conditions.Not;
bool isLike = (condNode.Condition & Conditions.Like) == Conditions.Like;
bool isIn = (condNode.Condition & Conditions.In) == Conditions.In;
bool isNull = (condNode.Condition & Conditions.Null) == Conditions.Null;
ResolveNodeContext lValueContext = new ResolveNodeContext(lValue, rValue, context);
ResolveNodeContext rValueContext = new ResolveNodeContext(rValue, lValue, context);
bool compareResult = true;
if (!isLike && !isIn && !isNull)
{
var leftVal = ResolveNodeValue(lValueContext);
var rightVal = ResolveNodeValue(rValueContext);
var cmpResult = Compare(leftVal, rightVal);
compareResult = false;
if ((condNode.Condition & Conditions.Equal) == Conditions.Equal && cmpResult == 0)
{
compareResult = true;
}
if ((condNode.Condition & Conditions.GreaterThan) == Conditions.GreaterThan && cmpResult > 0)
{
compareResult = true;
}
if ((condNode.Condition & Conditions.LessThan) == Conditions.LessThan && cmpResult < 0)
{
compareResult = true;
}
if ((condNode.Condition & Conditions.Not) == Conditions.Not)
{
compareResult = !compareResult;
}
}
else if (isLike)
{
string lString = Convert.ToString(ResolveNodeValue(lValueContext));
string rString = Convert.ToString(ResolveNodeValue(rValueContext));
bool startWildcard = rString.StartsWith("%");
bool endWildcard = rString.EndsWith("%");
if (startWildcard)
{
rString = rString.Substring(1);
}
if (endWildcard)
{
rString = rString.Substring(0, rString.Length - 1);
}
if (startWildcard && endWildcard)
{
compareResult = lString.Contains(rString);
}
else if (startWildcard)
{
compareResult = lString.EndsWith(rString);
}
else
{
compareResult = lString.StartsWith(rString);
}
}
else if (isIn)
{
object lObj = ResolveNodeValue(lValueContext);
object rObj = ResolveNodeValue(rValueContext);
if (!(rObj is IList))
{
throw new Exception("Condition 'In' expects IList as right operand");
}
compareResult = ((IList)rObj).Contains(lObj);
}
else if (isNull)
{
object lObj = ResolveNodeValue(lValueContext);
compareResult = lObj == null || lObj == DBNull.Value;
}
else
{
throw new Exception("Cannot apply conditions: " + condNode.Condition.ToString());
}
return(negate ? !compareResult : compareResult);
}
if (node is QueryGroupNode)
{
var groupNode = (QueryGroupNode)node;
bool groupResult = groupNode.GroupType == QueryGroupNodeType.And ? true : false;
foreach (QueryNode groupChildNode in groupNode.Nodes)
{
bool childResult = EvaluateInternal(context, groupChildNode);
if (groupNode.GroupType == QueryGroupNodeType.And)
{
groupResult = groupResult && childResult;
}
if (groupNode.GroupType == QueryGroupNodeType.Or)
{
groupResult = groupResult || childResult;
}
}
return(groupResult);
}
throw new Exception("Cannot resolve query node type: " + node.GetType().ToString());
}
