ApiView

Object serializer with

small codebase
focus on performance
benchmarks are guiding the implementation
only MultiJson as sole dependency

The initial code was copied from chetan and wrapped into a gem with unit-tests and a bit more convenient API ( original links )

Why should you even care? Is (… insert your favourite ruby serializer … ) not good enough?

you want great performance
you care about object allocations (less garbage to collect for the Ruby VM)
you want blazing fast test suite, so that you can switch globally the serialization off and test just the shape of the resulting Hash object -> no converting to JSON, then parsing JSON back and checking values on it, that sux!
really small and clean codebase
zero dependencies (NO ACTIVESUPPORT!), but you should use MultiJson + OJ for best performance.
unit-tested and with 100% test coverage

ApiView gives you all that and stays very small doing that.

Installation

## Add this line to your application's Gemfile:
gem 'api_view'


## And then execute:
$ bundle

Usage

you inherit from ApiView::Base
you say, what model should be serialized by default with this serializer (optional)
you specify an array of attributes, that will be copied from the object in serializer
you tell how you main object is called (defaults to object / obj)
you implement instance_convert-method for further customization of the serialization -> field - a setter method, that also accepts via: SomeSerializerApiView

class EventApiView < EventSummaryApiView
  # default serializer for BoxScore, will be picked, if none other was given
  for_model ::Event

  # the attributes to copy from the object
  attributes :share_url, :sport_name

  # the name of your main object, optional
  main_object :event

  # the method to add additional logic + fields
  def instance_convert
    # just a setter method with optional serializer for that sub-object
    field :box_score, event.box_score, via: BasketballBoxScoreApiView
  end
end

## a more complete example
class Event
  attr_accessor :game_date, :game_type, :status
end

class EventSerializer < ::ApiView::Base
  attributes :game_date, :game_type, :status
  main_object :event
  for_model ::Event

  # this is your chance to do extra work
  def instance_convert
    field :away_team,  "any value here"
  end
end

e = Event.new; e.game_date = Time.now; e.game_type = 'baseball'; e.status = 'won'
EventSerializer.render(e)

# because we configured the mapping from serializer to a Ruby class, this also works:
ApiView::Engine.render(e)

For more examples take a look into the example/-folder and run the benchmark script via ruby example/benchmark.rb.

Developement

# run tests
$ sh/test

Contributing

Fork it ( https://github.com/mindframer/api_view/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request

Benchmark numbers (ApiView vs the rest of the pack)

                                              user     system      total        real       allocations      memsize
RABL Ultra Simple                         4.860000   0.620000   5.480000 (  5.493406)              664        25787
AMS Ultra Simple                          0.220000   0.000000   0.220000 (  0.220079)               26          650
Presenters Ultra Simple                   0.140000   0.000000   0.140000 (  0.152729)               24          650
ApiView Ultra Simple                      0.190000   0.000000   0.190000 (  0.193124)               12          842
-------------------------------------------------------------------------------------------------------------------
RABL Simple                              21.470000   3.330000  24.800000 ( 25.147988)             2265       114051
AMS Simple                                1.060000   0.000000   1.060000 (  1.066668)              105         2726
Presenters Simple                         0.610000   0.000000   0.610000 (  0.611980)               98         2918
ApiView Simple                            0.280000   0.010000   0.290000 (  0.292290)               17         2246
-------------------------------------------------------------------------------------------------------------------
RABL Complex                             43.930000   6.850000  50.780000 ( 51.574975)             4325       248000
AMS Complex                               2.150000   0.000000   2.150000 (  2.160445)              209         5851
Presenters Complex                        1.210000   0.010000   1.220000 (  1.220806)              201         7395
ApiView Complex                           0.270000   0.000000   0.270000 (  0.270517)               21         1504


Collection tests:

                                              user     system      total        real       allocations      memsize
RABL Ultra Simple: Collection             3.560000   0.600000   4.160000 (  4.182852)            43102      1977224
AMS Ultra Simple: Collection              0.120000   0.000000   0.120000 (  0.124631)             1914        47786
Presenters Ultra Simple: Collection       0.100000   0.010000   0.110000 (  0.109781)             3508        67594
ApiView Ultra Simple: Collection          0.050000   0.000000   0.050000 (  0.050875)              311        46986
-------------------------------------------------------------------------------------------------------------------
RABL Simple: Collection                  18.720000   3.150000  21.870000 ( 21.924020)           202905     11255130
AMS Simple: Collection                    0.870000   0.010000   0.880000 (  0.890479)             9714       236186
Presenters Simple: Collection             0.540000   0.000000   0.540000 (  0.542100)            16108       380794
ApiView Simple: Collection                0.160000   0.000000   0.160000 (  0.166484)              812       187386
-------------------------------------------------------------------------------------------------------------------
RABL Complex: Collection                 41.190000   6.680000  47.870000 ( 48.438854)           408015     25251570
AMS Complex: Collection                   2.170000   0.030000   2.200000 (  2.211721)            20114       548686
Presenters Complex: Collection            1.380000   0.010000   1.390000 (  1.389608)            34408       960494
ApiView Complex: Collection               0.150000   0.000000   0.150000 (  0.145595)             1212       113186

Original links:

http://techblog.thescore.com/benchmarking-json-generation-in-ruby/#comment-1678429451
https://github.com/chetan/json_serialization_benchmark/tree/api_view
https://gist.github.com/chetan/d613e8f7d45600e1ca34