mongodb - Meteor Publish Distinct Values of Field in Collection -

i'm stuck on pretty simple scenario in meteor:

• i have huge collection of things many fields, of them containing quite bit of text.

• i want create page searching collection.

• one of fields each item in collection has "category".

• i'd give user ability filter category.

• for that, need publish distinct values of category field in collection.

i can't figure out way without publishing whole collection takes way long. how can publish distinct categories , use them fill dropdown?

bonus question , related: how publish count of items in collection without publishing whole collection?

a starting point make easier normalize categories separate database collection.

however assuming not possible or practical, best (though imperfect) solution publish 2 separate versions of collection, 1 returns categories field of entire collection , returns fields of collection selected category only. following:

// server meteor.startup(function(){    meteor.publish('allthings', function() {      // return id , categories field things      return things.find({}, {fields: {categories: 1}});    });    meteor.publish('thingsbycategory', function(category) {      // return fields things having selected category     // can subscribe via client-side session variable     // e.g., meteor.subscribe("thingsbycategory", session.get("category"));      return things.find({category: category});   }); }); 

note still need assemble array of categories client side things cursor (for example, using underscore's _.pluck , _.uniq methods grab categories , remove dups). data set smaller working single-field documents now.

(note ideally, want use mongo's distinct() method in publish function publish distinct categories, not possible directly returns array cannot published).