Sort and limit ReactiveAggregate

help
1

Hi, I’m using ReactiveAggregate. I could make the new collection and use it in the client side. What I coded is to take every word in the title of an article and then map it to all the articles that has that word in their title. Now what I want is to sort by count (descending) and limit the number of documents in the collection to 5. (I want the top 5 documents order by count).

var reg1 = new RegExp("^[A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ0-9]{1}$", "g");
var reg2 = new RegExp("^[A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ0-9]{2}$", "g");
var reg3 = new RegExp("^[A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ0-9]{3}$", "g");

Meteor.publish("topics", function () {
  ReactiveAggregate(this, Articles, [
    {
      $project: {
              topic: { $split: ["$title", " "] },
              date_seconds: 1,
              documento: "$$ROOT"
      }
    },
    {
      $unwind: {
              path: "$topic"
      }
    },
    {
      $match: {
              topic: { $nin: ["sports", reg1, reg2,reg3] },
              date_seconds: { $gte: timestamp }
      }
    },
    {
      $group: {
              _id: "$topic",
              count: { $sum: 1 },
              articles: { $push: "$documento" },
      }
    }
  ], { clientCollection: "clientTopic" });
});