Add findByAssociation to extendsTo

[ptnplanet]

I would like to suggest adding the findByAssociation method to models that are extended using extendsTo just like the one the hasOne association provides.

var User = db.define({
    username: String
});
var Account = User.extendsTo({
    facebookId: String
}, {
    table: 'account'
} );

// This would be nice:
User.findByAccount({
    facebookId: '123456789'
}, function (err, user) {
    // user
});

I don't quite understand, why this is possible though:

Account.findByUser({
    username: 'dude'
}, function (err, account) {
    // account
});

[dresende]

The second option is possible because in the background an extendsTo is a hasOne in the opposite direction and with some sugar. I'll see if I have time now to add the findBy* and add some tests for it.

[ptnplanet]

Ah, yes. Now I see it. With extendsTo a hasOne association is created in the opposite direction - the extended table gets the foreign id and uses it as its primary key. Creating a hasOne in the other direction would put the foreign id in the base table and the extended table would need a primary key on its own.

The method for creating findBy* would then need to be shared by hasOne and by extendsTo.

[ptnplanet]

Thanks!