I’m happy to announce that after 1486 commits Virtus 1.0.0 has been released.
It comes with a lot of neat changes, improvements and new features.
Here’s a quick summary of my favorite additions and changes.
No more “include Virtus”
That’s right. With 1.0.0 including Virtus module is deprecated. Instead you should
use something called “custom extension builder”. It’s really cool, check this out:
# for classes class User include Virtus.model # attributes go here end # for modules module CommonAttributes include Virtus.module # attributes go here end
The reason for this change is that your classes and modules won’t be polluted
with Virtus namespace…but that’s not everything…
With the extension builder you can now build virtus modules that can hold custom
configuration. This means you can set various options that will be used in your
models and modules. This is a really sweet feature:
class User include Virtus.model(:coerce => false) attribute :name_that_will_not_be_coerced, String end
This is my favorite change and on top of that we have…
NO WAY! Yes, way. You can now decide which features should be included. It’s as
easy as that:
# this model won't have the constructor that accepts attribute hash class User include Virtus.model(:constructor => false) # attributes go here end # and this one won't have mass-assignment # which means #attributes and #attributes= won't be added class Book include Virtus.model(:mass_assignment => false) # attributes go here end
Strict Coercion Mode
You can now use a special “strict” mode when you want to hear loud exceptions
every time an input value failed to be coerced to the expected type:
# using module-level setting class User include Virtus.model(:strict => true) attribute :age, Integer end # or the equivalent using per-attribute setting class User include Virtus.model attribute :age, Integer, :strict => true end User.new(:age => 'very young') # BOOM! Virtus::CoercionError
Public Attribute API
It’s now easy to create attribute instances on your own and use their public
attr = Virtus::Attribute.build(String) attr.coerce('1') # => 1 # or maybe something more fancy Money = Struct.new(:amount, :currency) attr = Virtus::Attribute.build(Array[Money]) attr.coerce([[49, 'USD'], [29, 'EU']]) # => [ # #<struct Money amount=49, currency="USD">, # #<struct Money amount=29, currency="EU"> # ]
You can check out Attribute API docs
for more information.
In Virtus 0.5.x default value was being set when accessing an attribute for the
first time. This has changed and now all default values are set in the constructor.
If you want to have previous behavior just use :lazy option:
class User include Virtus.model attribute :email, String, :default => 'email@example.com' attribute :name, String, :lazy => true, :default => 'Jane Doe' end user = User.new # :email is now set but :name remains as nil user.name # :name is set to the default value
This change should address the performance issue that some people had when loading
A LOT of virtus objects and reading A LOT OF attributes. Please keep in mind that
it slows down initialization so if you find it problematic just set :lazy to true
in your custom module or skip including virtus’ constructor.
Finalization With Constant Name Evaluation
Finally the circular dependency problem with constant names has been resolved.
Here’s how you can use it:
# user.rb class User include Virtus.model(:finalize => false) attribute :address, 'Address' end # address.rb class Address include Virtus.model(:finalize => false) attribute :street, String attribute :city, String attribute :zipcode, String end Virtus.finalize # this should be called after all your files were loaded
If you find any issues please report them on
Future Plans For 2.0
Even though releasing 1.0.0 is a huge milestone for the project I’ve already
started thinking about the future 2.0.0 version.
At the moment it seems like trimming down Virtus codebase is a good direction.
Currently I’m considering removing complex coercion/mapping logic from Virtus
and integrating it with Ducktrap which is a
crazy powerful transformation algebra library. It’s still in its early days but
is very promising. Virtus would remain as a “container” for various extensions
providing nice DSL to configure them.
I want to thank all of the contributors
and everybody who helped me with testing early 1.0.0 betas and RCs.
Thanks! I really appreciate your help.
Have fun using Virtus 1.0.0 🙂