You could write something like this that builds your query function dynamically:
public static Func<ObjT, bool> PropertyCheck<ObjT, PropT>(string propertyName, Expression<Func<PropT, bool>> predicate)
{
var paramExpr = Expression.Parameter(typeof(ObjT));
var propExpr = Expression.Property(paramExpr, propertyName);
return Expression.Lambda<Func<ObjT, bool>>(Expression.Invoke(predicate, propExpr), paramExpr).Compile();
}
Then, it could be used like this:
foos.Where(PropertyCheck<Foo, int>("MyId", x => idList.Contains(x)));
Of course, you could also just provide your own Where
extension method that does all that at once:
public static IEnumerable<T> Where<T, PropT>(this IEnumerable<T> self, string propertyName, Expression<Func<PropT, bool>> predicate)
{
var paramExpr = Expression.Parameter(typeof(T));
var propExpr = Expression.Property(paramExpr, propertyName);
return self.Where<T>(Expression.Lambda<Func<T, bool>>(Expression.Invoke(predicate, propExpr), paramExpr).Compile());
}
foos.Where<Foo, int>("MyId", x => idList.Contains(x));