Valid geoNear aggregate query returns nothing in Mongoskin

Question

I've been building a small API in Express and Mongoskin. I added a simple aggregrate geoNear query to respond to params given. The server returns 200 and I get no error. I know that I'm pointing to the right collection and everything, and when I run the query in Mongo's shell it works fine. The code is below:

app.get('/collections/:collectionName/geonear', function(req, res, next) {
  req.collection.aggregate([
  {
        "$geoNear": {
            "near": [req.query.lng, req.query.lat],
             "distanceField": "distance"
         }
    },
    {
         "$sort": {"distance": -1}
    }
],
function(e, results) {
  res.send(results);
});
});

chridam · Accepted Answer · 2015-05-06T15:07:03.693

The problem is you are passing request query strings in your near array instead of integers, so try parsing them to return integers first using parseInt():

app.get('/collections/:collectionName/geonear', function(req, res, next) {
    var lng = parseInt(req.query.lng),
        lat = parseInt(req.query.lat);
    req.collection.aggregate(
        [
            {
                "$geoNear": {
                    "near": [lng, lat],
                    "distanceField": "distance"
                }
            },
            {
                "$sort": {"distance": -1}
            }
        ], 
        function(e, results) {
            res.send(results);
    });
})

-- UPDATE --

From the OP @JeffLuppes:

Since this works with coordinates it's better to parse them as floats to preserve the full coordinate input. Instead of parseInt() I used parseFloat().

The revised solution is to use parseFloat():

app.get('/collections/:collectionName/geonear', function(req, res, next) {
        var lng = parseFloat(req.query.lng),
            lat = parseFloat(req.query.lat);
        req.collection.aggregate(
            [
                {
                    "$geoNear": {
                        "near": [lng, lat],
                        "distanceField": "distance"
                    }
                },
                {
                    "$sort": {"distance": -1}
                }
            ], 
            function(e, results) {
                res.send(results);
        });
    })

Since this works with coordinates it's better to parse them as floats to preserve the full coordinate input. Instead of parseInt() I used parseFloat(). — JeffLuppes, May 06 '15 at 15:01
@JeffLuppes Thanks for the update, I've also updated the solution to reflect this. — chridam, May 06 '15 at 15:07

Valid geoNear aggregate query returns nothing in Mongoskin

1 Answers1