How to add a $geoWithin constraint to a query in parse server?

Question

I tried to add a $geoWithin constraint to a Parse.Query like so:

var query = new Parse.Query("MyCollection");
var jsonQuery = query.toJSON();

jsonQuery.where.location = {
    "$geoWithin": {
        "$centerSphere": [
            [geoPoint.longitude, geoPoint.latitude],
            10 / 6371.0
        ]
    }
};

query.withJSON(jsonQuery);

It throws the error:

bad $geoWithin value; $polygon should contain at least 3 GeoPoints.

The reason is apparently that Parse Server's Mongo Transformer only accepts a polygon parameter with $geoWithin.

How can I add a query constraint that limits the results to documents with a location field within a certain radius in km of a geo coordinate?

Answer 1

It turned out that Parse Server did not support this type of query. But since Parse Server is an open source project on Github, I added the feature*.

The code in the question works and the same can be achieved setting the new sorted parameter in geo queries to false:

var location = new Parse.GeoPoint(37.708813, -122.526398);
var distance = 5;
var sorted = false;

var query = new Parse.Query(MyCollection);
query.withinKilometers("location", location, distance, sorted);

*Feature not yet available as of Parse Server v2.8.2 and JS SDK v1.11.1, waiting for merge of pull requests.