public static IQueryable<T> SearchBy<T>(this IQueryable<T> query, Dictionary<string, StringValues> searchTerms, LambdaLogicalOp logicalOp)
{
if (searchTerms.Any())
{
var predicate = PredicateBuilder.New<T>(true);
foreach (var searchTerm in searchTerms)
{
ParameterExpression param = Expression.Parameter(typeof(T), "x");
MemberExpression memberExpression =
Expression.MakeMemberAccess(param, typeof(T).GetProperty(searchTerm.Key));
// TODO: this assumes properties are of type string. This will need to be refactored to account for numeric and date types
MethodInfo methodInfo = typeof(string).GetMethod("Contains", new Type[] {typeof(string)});
var toLowerExpression = Expression.Call(memberExpression, ToLowerMethod);
var tempSearchTerm = searchTerm.Value.ToString();
ConstantExpression constant = Expression.Constant(tempSearchTerm.ToLower());
var call = Expression.Call(toLowerExpression, methodInfo, constant);
Expression<Func<T, bool>> lambda = Expression.Lambda<Func<T, bool>>(call, param);
if (logicalOp == LambdaLogicalOp.And)
{
predicate = predicate.And(lambda);
}
else
{
predicate = predicate.Or(lambda);
}
}
query = query.AsExpandable().Where(predicate);
return query;
}
return query;
}
public static IQueryable<T> SearchBy<T>(this IQueryable<T> query, string searchTerm, string[] attributes, LambdaLogicalOp logicalOp)
{
if (attributes.Any())
{
var predicate = PredicateBuilder.New<T>(true);
foreach (var attibute in attributes)
{
if (!string.IsNullOrEmpty(attibute))
{
ParameterExpression param = Expression.Parameter(typeof(T), "x");
MemberExpression memberExpression = Expression.MakeMemberAccess(param, typeof(T).GetProperty(attibute));
// TODO: this assumes properties are of type string. This will need to be refactored to
// account for numeric and date types
MethodInfo methodInfo = typeof(string).GetMethod("Contains",
new Type[] {
typeof(string)
});
var toLowerExpression = Expression.Call(memberExpression, ToLowerMethod);
var tempSearchTerm = searchTerm; // used to avoid the outer variable trap
ConstantExpression constant = Expression.Constant(tempSearchTerm);
var call = Expression.Call(toLowerExpression, methodInfo, constant);
//var call = Expression.Call(toLowerCall, methodInfo, toLowerCall);
Expression<Func<T, bool>> lambda = Expression.Lambda<Func<T, bool>>(call, param);
if (logicalOp == LambdaLogicalOp.And)
{
predicate = predicate.And(lambda);
}
else
{
predicate = predicate.Or(lambda);
}
//query = query.AsExpandable().Where(lambda);
}
}
query = query.AsExpandable().Where(predicate);//.AsQueryable();
return query;
}
return query;
}
