Mongoose: what's up with “_doc”?

Question

It seems Mongoose is doing something really funky internally.

1 var Foo = new mongoose.model(\'Foo\', new mongoose.Schema({a: String, b: Number}));
2 var foo         


        

Answer 1

I was stuck on this today... Drove me nuts. Not sure if the below is a good solution (and OP has mentioned it too), but this is how I overcame this issue.

My car object:

 cars = [{"make" : "Toyota"}, {"make" : "Kia"}];

Action:

console.log("1. Cars before the color: " + car);

cars.forEach(function(car){
     car.colour = "Black";   //color is NOT defined in the model. 
});

console.log("2. Cars after the color: " + car);

Problematic console output:

   1. Cars before the color: [{"make" : "Toyota"}, {"make" : "Kia"}];
   2. Cars after the color: [{"make" : "Toyota"}, {"make" : "Kia"}];   //No change! No new colour properties :(

If you try to pass in this property that was undefined in the model, via doc (e.g. car._doc.color = "black"), it will work (this colour property will be assigned to each car), but you can't seem to access it via EJS (frontend) for some reason.

Solution: (Again, not sure if this is the best way... but it worked for me): Add in this new property (colour) in the car model.

var carSchema = mongoose.Schema({
   make: String,
   color: String   //New property.
})

With the model redefined, everything worked as normal / expected (no _doc 'hacks' needed etc.) and I lived another day; hope it helps someone else.