How can I translate this linq query to a breeze query - breeze

Question

I am in the process of learning Durandal and Breeze. And have choosing to create a SPA version of nerddinner.
The first query I need to execute is this:
public IEnumerable<JsonDinner> GetMostPopularDinners(int limit = 10)
{
var mostPopularDinners = from dinner in _db.Context.Dinners.Include("RSVPs")
where dinner.EventDate >= DateTime.Now
orderby dinner.RSVPs.Count descending
select dinner;
if (limit > 50 || limit <= 0)
limit = 10;
return mostPopularDinners.Take(limit).AsEnumerable().Select(JsonDinnerFromDinner);
}
I have started to write it with breeze but I am having trouble with this line " orderby dinner.RSVPs.Count descending" this is what I have so far.
var getMostPopularDinners = function() {
var query = EntityQuery
.from('dinners')
.where('eventDate', '>=', new Date(Date.now()))
.orderByDesc('RSVPs')
.expand('RSVPs');

Answer 1

Sorry, Breeze doesn't yet support ordering or filtering on an aggregate value ('count' in this case).
What you can do is turn this into a named query. (which is not well documented...) Basically this involves using the EntityQuery.withParameters method to pass additional parameters to any service method. So you can construct a query like the following that both passes parameters and still uses Breeze's IQueryable support.
EntityQuery.from("GetMostPopularDinners")
.withParameters({ EventDate: new Date(Date(now()) })
.take(10);
where your controller method would look something like this:
[HttpGet]
public IQueryable<Dinner> GetMostPopularDinners(DateTime eventDate) {
return _db.Context.Dinners.
.Where(dinner => dinner.EventDate >= eventDate)
.OrderByDescending(dinner => dinner.RSVPs.Count);
}
and ... you should not need to do an JsonDinnerFromDinner" call; Breeze handles this automatically.