added Model.primary(name) to set the key

[ianstormtaylor]

I've been wanting to have a nicer way to set the primary key for a model. Instead of having to break the nice chainable API to do:

var Model = model('post')
  .attr('id')
  .attr('slug')
  .attr('title')
  .attr('body');

Model.primaryKey = 'slug';

Instead, we can add a chainable method to set the primaryKey. Note that I removed the model[attr].primaryKey = true piece of code because it seemed unnecessary and wasn't being used anywhere, so I figured it was a bit of feature creep for now.

Now setting a primaryKey would look like:

var Model = model('post')
  .attr('id')
  .attr('slug')
  .attr('title')
  .attr('body')
  .primary('slug');

But then I realized that there might even be a better way using the extra options we can tie to a specific property, which would look like this:

var Model = model('post')
  .attr('id')
  .attr('slug', { primary: true })
  .attr('title')
  .attr('body');

That last option seems the cleanest to me, and it builds on the existing API. (Note: that's not what's in the PR, so let me know if you like that one better and I'll submit another with it.)

[tj]

hmmm yeah I like the last one too

[ianstormtaylor]

how do you feel about changing primaryKey to primary? just worried about having both in there since the method is primary() and the current prop is primaryKey.

[tj]

SGTM

[yocontra]

Any updates on this?

[ianstormtaylor]

when #58 gets merged (sorry getting distracted) this will be fixed