Referring to session-based data in a Mongoose virtual attribute
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I have a Mongoose model that holds Places. Each *place* has a lat/lng. I can define a Mongoose [virtual attribute][1] called *distance* that would be used to sort Places in ascending order. What's the best way to refer to the user's location information (let's assume it's stored in a session variable for now) from inside the *distance* virtual attribute?

  [1]: http://mongoosejs.com/docs/virtuals.html