### Development
[full changelog](http://github.com/plexus/yaks/compare/v0.4.2...master)

* when specifying a rel_template, instead of allowing for {src} and {dest} fields, now a single {rel} field is expected, which corresponds more with typical usage.

```ruby
Yaks.new do
  rel_template 'http://my-api/docs/relationships/{rel}'
end
```

* Yaks::Serializer has been renamed to Yaks::Format

* Yaks::Mapper#{map_attributes,map_links,map_subresource} signature has changed, they now are responsible for adding themselves to a resource instance.

```ruby
class FooMapper < Yaks::Mapper
  def map_attributes(resource)
    resource.update_attributes(:example => 'attribute')
  end
end
```

* Conditionally turn associations into links

```ruby
class ShowMapper < Yaks::Mapper
  has_many :events, href: '/show/{id}/events', link_if: ->{ events.count > 50 }
end
```

* Reify `Yaks::Mapper::Attribute`

* Remove `Yaks::Mapper#filter`, instead override `#attributes` or `#associations` to filter things out, for example:

```ruby
class SongMapper
  attributes :title, :duration, :lyrics
  has_one :artist
  has_one :album

  def minimal?
    env['HTTP_PREFER'] =~ /minimal/
  end

  def attributes
    if minimal?
      super.reject {|attr| attr.name.equal? :lyrics } # These are instances of Yaks::Mapper::Attribute
    else
      super
    end
  end

  def associations
    return [] if minimal?
    super
  end
end
```

* Give Attribute, Link, Association a common interface : `add_to_resource(resource, mapper, context)`
* Add persistent update methods to `Yaks::Resource`

### v0.4.2

* JSON-API: render self links as href attributes
* HAL: render has_one returning nil as null, not as {}
* Keep track of the mapper stack, useful for figuring out if mapping the top level response or not, or for accessing parent
* Change Serializer.new(resource, options).serialize to Serializer.new(options).call(resource) for cosistency of "pipeline" interface
* Make Yaks::CollectionMapper#collection overridable for pagination
* Don't render links from custom link methods (link :foo, :method_that_generates_url) that return nil

### v0.4.1

* Change how env is passed to yaks.serialize to match docs
* Fix JSON-API bug (#18 reported by Nicolas Blanco)
* Don't pluralize has_one association names in JSON-API

## v0.4.0

* Introduce after {} post-processing hook
* Streamline interfaces and variable names, especially the use of `call`
* Improve deriving mappers automatically, even with Rails style autoloading
* Give CollectionResource a members_rel, for HAL-like formats with no top-level collection concept
* Switch back to using `src` and `dest` as the rel-template keys, instead of `association_name`
* deprecate `mapper_namespace` in favor of `namespace`

### v0.4.0.rc1

* Introduce Yaks.new as the main public interface
* Fix JsonApiSerializer and make it compliant with current spec
* Remove Hamster dependency, Yaks new uses plain old Ruby arrays and hashes
* Remove `RelRegistry` and `ProfileRegistry` in favor of a simpler explicit syntax + policy based fallback
* Add more policy derivation hooks, plus make `DefaultPolicy` template for rel urls configurable
* Optionally take a Rack env hash, pass it around so mappers can inspect it
* Honor the HTTP Accept header if it is present in the rack env
* Add map_to_primitive configuration option

## v0.3.0

* Allow partial expansion of templates, expand certain fields, leave others as URI template in the result.

## v0.2.0

* links can now take a simple for a template to compute a link just like an attribute