/// <summary>
/// Tries to evaluate the current expression and add it as a projection
/// </summary>
private Expression AddProjection(Expression node, PocoColumn column = null)
{
var value = Expression.Lambda(node).Compile().DynamicInvoke();
if (column == null)
{
column = _pocoData.GetColumnByMemberName(_currentBindingName.Get());
if (column == null)
{
throw new CqlLinqNotSupportedException(node, _parsePhase.Get());
}
}
_projections.Add(Tuple.Create(column, value, ExpressionType.Assign));
return(node);
}
protected override Expression VisitMemberInit(MemberInitExpression node)
{
if (_parsePhase.Get() != ParsePhase.SelectBinding)
{
throw new CqlLinqNotSupportedException(node, _parsePhase.Get());
}
// Visit new instance creation (constructor and parameters)
VisitNew(node.NewExpression);
foreach (var binding in node.Bindings)
{
if (!(binding is MemberAssignment))
{
continue;
}
using (_currentBindingName.Set(binding.Member.Name))
{
Visit((binding as MemberAssignment).Expression);
}
}
return(node);
}
private bool EvaluateMethod(string name, MethodCallExpression node)
{
var clause = _currentCondition.Get().Item1;
var parameters = _currentCondition.Get().Item2;
switch (name)
{
case "Contains":
{
Expression what;
Expression inp;
if (node.Object == null)
{
what = node.Arguments[1];
inp = node.Arguments[0];
}
else
{
what = node.Arguments[0];
inp = node.Object;
}
Visit(what);
var values = (IEnumerable)Expression.Lambda(inp).Compile().DynamicInvoke();
var placeHolders = new StringBuilder();
foreach (var v in values)
{
placeHolders.Append(placeHolders.Length == 0 ? "?" : ", ?");
parameters.Add(v);
}
clause
.Append(" IN (")
.Append(placeHolders)
.Append(")");
return(true);
}
case "StartsWith":
Visit(node.Object);
var startsWithArgument = node.Arguments[0];
var startString = (string)Expression.Lambda(startsWithArgument).Compile().DynamicInvoke();
var endString = startString + _utf8MaxValue;
parameters.Add(startString);
parameters.Add(endString);
clause
.Append(" ")
.Append(CqlTags[ExpressionType.GreaterThanOrEqual])
.Append(" ? ")
.Append(CqlTags[ExpressionType.And])
.Append(" ");
Visit(node.Object);
clause
.Append(" ")
.Append(CqlTags[ExpressionType.LessThan])
.Append(" ?");
return(true);
case "CompareTo":
Visit(node.Object);
clause
.Append(" ")
.Append(_binaryExpressionTag.Get())
.Append(" ");
Visit(node.Arguments[0]);
return(true);
case "Equals":
Visit(node.Object);
clause.Append(" = ");
Visit(node.Arguments[0]);
return(true);
case "CqlToken":
case "Token":
clause.Append("token(");
var tokenArgs = node.Arguments;
for (var i = 0; i < tokenArgs.Count; i++)
{
var arg = tokenArgs[i];
if (i > 0)
{
clause.Append(", ");
}
Visit(arg);
}
clause.Append(")");
return(true);
case "MaxTimeUuid":
case "MinTimeUuid":
clause.Append(name.ToLowerInvariant()).Append("(");
Visit(node.Arguments[0]);
clause.Append(")");
return(true);
}
return(false);
}
private Expression EvaluateConditionFunction(MethodCallExpression node)
{
var methodName = node.Method.Name;
if (node.Method.DeclaringType != null)
{
if (node.Method.DeclaringType == typeof(CqlToken))
{
methodName = "CqlToken";
}
}
if (EvaluateMethod(methodName, node))
{
//It was evaluated as one of the methods
return(node);
}
//Try to invoke to obtain the value
var val = Expression.Lambda(node).Compile().DynamicInvoke();
_currentCondition.Get().Item2.Add(val);
_currentCondition.Get().Item1.Append("?");
return(node);
}
private bool EvaluateMethod(string name, MethodCallExpression node)
{
var clause = _currentCondition.Get().Item1;
var parameters = _currentCondition.Get().Item2;
switch (name)
{
case "Contains":
{
EvaluateContainsMethod(node, clause, parameters);
return(true);
}
case "StartsWith":
Visit(node.Object);
var startsWithArgument = node.Arguments[0];
var startString = (string)Expression.Lambda(startsWithArgument).Compile().DynamicInvoke();
var endString = startString + _utf8MaxValue;
parameters.Add(startString);
parameters.Add(endString);
clause
.Append(" ")
.Append(CqlTags[ExpressionType.GreaterThanOrEqual])
.Append(" ? ")
.Append(CqlTags[ExpressionType.And])
.Append(" ");
Visit(node.Object);
clause
.Append(" ")
.Append(CqlTags[ExpressionType.LessThan])
.Append(" ?");
return(true);
case "CompareTo":
Visit(node.Object);
clause
.Append(" ")
.Append(_binaryExpressionTag.Get())
.Append(" ");
Visit(node.Arguments[0]);
return(true);
case "Equals":
Visit(node.Object);
clause.Append(" = ");
Visit(node.Arguments[0]);
return(true);
case "CqlToken":
case "Token":
clause.Append("token(");
var tokenArgs = node.Arguments;
for (var i = 0; i < tokenArgs.Count; i++)
{
var arg = tokenArgs[i];
if (i > 0)
{
clause.Append(", ");
}
Visit(arg);
}
clause.Append(")");
return(true);
case "MaxTimeUuid":
case "MinTimeUuid":
clause.Append(name.ToLowerInvariant()).Append("(");
Visit(node.Arguments[0]);
clause.Append(")");
return(true);
}
return(false);
}
