MeteorJS and UnderscoreJS: grouping results to plot points on a Google Map - google-maps

Question

I am working on a small MeteorJS app that plots points on a map based on popular areas for work.
I have this:
Template.list.jobs = function() {
if(Session.get('currentIndustryOnet')) {
jobs = Jobs.find({onet: Session.get('currentIndustryOnet')}).fetch();
// Session.set('jobCount', jobs.count());
var cnt = _.groupBy(jobs, 'address');
console.log(cnt);
return Pagination.collection(jobs);
} else {
jobs = Jobs.find()
Session.set('jobCount', jobs.count());
return Pagination.collection(jobs.fetch());
}
}
The cnt variable returns a properly grouped array (the key of the array is an address like Allentown, PA). I have a collection of Cities which have ever city in the USA along with their LAT/LONGs to plot on a Google Map. So I will take the top 100 from the grouped array, find the lat/long in the Cities collection and plot those points on a map.
I am not familiar with working with a groupedBy method to sort the list based on the length and then pull out the key to use as my search.

Answer 1

I'm not 100% certain about the data structure... but assuming jobs have an address field, and you want them sorted by frequency of occurrence and capped, you could do something like this:
var addresses = _.chain(jobs)
.countBy('address')
.pairs()
.sortBy(function(j) {return -j[1];})
.map(function(j) {return j[0];})
.first(100)
.value();
Note there may be a more clever way to use underscore to arrive at this result. Once you have the capped, sorted list of addresses, you can probably get the lat/long values via a find like:
Cities.find({address: {$in: addresses}}).fetch();