Mongoose schemas with unknown keys and nested documents as values

Question

I have a document out of Mongo that looks something like this:

{
    teacher: { name: 'Fred' },
    principal: { name: 'Bob' },
    student: { name: 'Sally' }
}

In my case, the properties of "teacher", "principal" and "student" are totally arbitrary and can be any old string. It's unknown before this particular document is loaded what they will be. However, I know that every value of every property at this document level will be of the same type and can therefore validate it.

I would like to make each of these values a sub-document within Mongoose (a "Person") to leverage Mongoose's validation; however, I cannot find a way to tell mongoose to treat all values as the same schema type regardless of key.

By the way, I can't convert this into an array where each Person has "role" type or anything like that. I unfortunately don't control the data structure, I just get to consume it!

Any ideas appreciated!

Mattias Farnemyhr Mattias Farnemyhr · Accepted Answer · 2014-09-15T21:45:12

If you recieve this as a dict, you could implement a converter method that attempts to parse each key value as a Person, something like this:

var utils = require('restberry-utils');

var PersonSchema = new mongoose.Schema({
    name: {type: String},
    ...
});
var Person = mongoose.model('Person', PersonSchema);

var parsePersons = function(persons, next) {
    var parsedPersons = {};
    var names = Object.keys(persons);
    utils.forEachAndDone(names, function(name, iter) {
        var personData = persons[name];
        Person.findOne(personData, function(err, person) {
            if (err) ...
            if (!person) {
                person = new Person(personData);
            }
            parsedPersons[name] = person;
            person.save(iter);
        })
    }, function() {
        next(parsedPersons);
    })
};

var persons = ...  // your dict
parsePersons(persons, function(parsedPersons) {
    ...
});

Does this solve your problem?

Mongoose schemas with unknown keys and nested documents as values

1 Answers