protected override Expression VisitBinary(BinaryExpression node)
{
if (node.NodeType == ExpressionType.AndAlso)
{
this.Visit((BinaryExpression)node.Left);
this.Visit((BinaryExpression)node.Right);
return(node);
}
else if (node.NodeType == ExpressionType.OrElse)
{
var filter = new Or {
Operator = node.NodeType.ToString()
};
var whereVisitor = new WhereClauseVisitor();
whereVisitor.lambdaExpression = this.lambdaExpression;
whereVisitor.Visit(node.Left);
whereVisitor.Visit(node.Right);
filter.Clauses = whereVisitor.Filters;
filter.Expression = Expression.Lambda(node, parameter);
_filters.Add(filter);
return(node);
}
else
{
var filter = new Where();
var member = node.Left as MemberExpression;
if (member == null)
{
var unaryMember = node.Left as UnaryExpression;
if (unaryMember != null)
{
member = unaryMember.Operand as MemberExpression;
}
}
if (member != null)
{
filter.PropertyName = member.Member.Name;
}
filter.Expression = Expression.Lambda(node, parameter);
filter.Operator = node.NodeType.ToString();
var valueNode = parameter != null && parameter == (node.Right as MemberExpression)?.Expression
? node.Left
: node.Right;
filter.Value = GetValueFromExpression(valueNode);
_filters.Add(filter);
return(node);
}
}
// override ExpressionVisitor method
protected override Expression VisitMethodCall(MethodCallExpression m)
{
if ((m.Method.DeclaringType == typeof(Queryable)) || (m.Method.DeclaringType == typeof(Enumerable)))
{
if (m.Method.Name.Equals("Skip"))
{
Visit(m.Arguments[0]);
var countExpression = (ConstantExpression)(m.Arguments[1]);
QueryInfo.Skip = ((int)countExpression.Value);
return(m);
}
else if (m.Method.Name.Equals("Take"))
{
Visit(m.Arguments[0]);
var countExpression = (ConstantExpression)(m.Arguments[1]);
QueryInfo.Take = ((int)countExpression.Value);
return(m);
}
else if (m.Method.Name.Equals("Select"))
{
MethodCallExpression call = m;
LambdaExpression lambda = (LambdaExpression)ExpressionUtils.RemoveQuotes(call.Arguments[1]);
Expression body = ExpressionUtils.RemoveQuotes(lambda.Body);
Select = new ExpressionUtils.SelectCallMatch
{
MethodCall = call,
Source = call.Arguments[0],
Lambda = lambda,
LambdaBody = body
};
}
else if (m.Method.Name.Equals("OrderByDescending"))
{
MethodCallExpression call = m;
var lambda = (LambdaExpression)ExpressionUtils.RemoveQuotes(call.Arguments[1]);
var lambdaBody = (MemberExpression)ExpressionUtils.RemoveQuotes(lambda.Body);
QueryInfo.OrderBy = new OrderBy(lambdaBody.Member.Name, OrderBy.OrderByDirection.Desc);
}
else if (m.Method.Name.Equals("OrderBy"))
{
MethodCallExpression call = m;
var lambda = (LambdaExpression)ExpressionUtils.RemoveQuotes(call.Arguments[1]);
var lambdaBody = (MemberExpression)ExpressionUtils.RemoveQuotes(lambda.Body);
QueryInfo.OrderBy = new OrderBy(lambdaBody.Member.Name, OrderBy.OrderByDirection.Asc);
}
else if (m.Method.Name.Equals("Where"))
{
MethodCallExpression call = m;
var whereClause = call.Arguments[1];
var whereClauseVisitor = new WhereClauseVisitor();
whereClauseVisitor.Visit(whereClause);
QueryInfo.Clauses = QueryInfo.Clauses.Concat((whereClauseVisitor.Filters)).ToArray();
}
else if (m.Method.Name.Equals("GroupBy"))
{
MethodCallExpression call = m;
LambdaExpression keyExpression = (LambdaExpression)ExpressionUtils.RemoveQuotes(call.Arguments[1]);
Expression body = ExpressionUtils.RemoveQuotes(keyExpression.Body);
QueryInfo.GroupBy = new GroupBy()
{
KeySelector = new ExpressionUtils.SelectCallMatch
{
MethodCall = call,
Source = call.Arguments[0],
Lambda = keyExpression,
LambdaBody = body
}
};
}
else if (m.Method.Name.Equals("Single"))
{
QueryInfo.ResultType = new Single();
}
else if (m.Method.Name.Equals("Count"))
{
QueryInfo.ResultType = new Count();
}
else
{
throw new NotImplementedException($"Operator {m.Method.Name} not supported. Please update the project at https://github.com/mcintyre321/LinqToAnything/blob/master/LinqToAnything/QueryVisitor.cs");
}
}
return(m);
}
