crunchr¶ ↑

Given an ORM-model that makes snapshots with counts off your data
When I include Crunchr
Then I can do all kinds of nifty calculations

# Given an ORM-mode that makes snapshots
class Statistic < ActiveRecord::Base
  serialize :data

  def self.snapshot
    Statistic.create(
      data: {
        keys: Key.count,
        doors: Door.count,
        rooms: {
          count: Room.count,
          occupied: Room.occupied.count
        }
      }
    )
  end

  # When I include Crunchr
  include Crunchr
end

# Then I can doo all kinds of nifty things
s = Statistic.last

# like, fetch data
s.fetch('keys')                # 10
s.fetch('doors')               # 8
s.fetch('rooms/count')         # 7

# do calculations
s.fetch('keys x doors')        # 80
s.fetch('keys - doors')        # 2 spare keys...
s.fetch('doors / rooms/count') # 1.1428 doors per room

# make deltas
delta = s.delta(Statistic.first)
delta.fetch('keys')           # 10 (now) - 5 (then) = 5
delta.fetch('keys - doors')   # 5 (see above) - 8   = -3
delta.fetch('rooms/occupied') # 0 (did not change)

# make tables
rows = Statistic.where( "created_at > ?", 1.week.ago )
Statistic.as_table( rows, keys: ['keys',  'doors', 'keys / doors'] )
# => [
#   [ 9, 8, 1.125 ]
#   [ 9, 8, 1.125 ]
#   [ 7, 8, 0.875 ]
#   [ 10, 8, 1.25 ]
# ]

• Use created_at as a way to group data for ActiveModel (alike) includers

• Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet.

• Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it.

• Fork the project.

• Start a feature/bugfix branch.

• Commit and push until you are happy with your contribution.

• Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.

• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright © 2013 Hartog C. de Mik. See LICENSE.txt for further details.