Class: Bluecap::Engagement

Inherits:
Object
  • Object
show all
Defined in:
lib/bluecap/engagement.rb

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Engagement

Initialize an Engagement class to measure Cohort retention.

options - A hash containing options that define the engagement.

:cohort           - The Cohort to measure engagement for.
:engagement_event - The String event that defines engagement.
:start_date       - The Date starting period to measure
                    engagement for.
:end_date         - The Date ending period to measure
                    engagement for.
:report_id        - The Integer identifier of the report this
                    cohort is being used with.

Examples

engagement = Bluecap::Engagement.new :cohort => cohort,
  :engagement_event => 'Logged In',
  :start_date => Date.parse('20120702'),
  :end_date => Date.parse('20120707'),
  :report_id => 1



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# File 'lib/bluecap/engagement.rb', line 23

def initialize(options)
  @cohort = options.fetch(:cohort)
  @engagement_event = options.fetch(:engagement_event)
  @start_date = options.fetch(:start_date)
  @end_date = options.fetch(:end_date)
  @report_id = options.fetch(:report_id)
end

Instance Method Details

#key(date) ⇒ Object

A key name in Redis where the bitcount operation for engagement on a date should be stored.

Returns the String key name.



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# File 'lib/bluecap/engagement.rb', line 35

def key(date)
  Bluecap::Keys.engagement(@report_id, @cohort.id, date.strftime('%Y%m%d'))
end

#keys(date) ⇒ Object

The keys that comprise the bitmask for the engagement on a date.

Returns the Array of String keys.



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# File 'lib/bluecap/engagement.rb', line 42

def keys(date)
  [@cohort.key, Bluecap::Keys.event(@engagement_event, date.strftime('%Y%m%d'))]
end

#measure ⇒ Object

Measure the engagement of a cohort over a given period.

Examples

measure
# => {"20120702" =>  100.0, "20120703" => 50.0, ...}

Returns a Hash with engagement percentages for each day in the period.



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# File 'lib/bluecap/engagement.rb', line 54

def measure
  results = Hash.new
  (@start_date..@end_date).each do |date|
    key_name = key(date)
    Bluecap.redis.multi do
      Bluecap.redis.bitop('and', key_name, keys(date))
      Bluecap.redis.expire(key_name, 3600)
    end
    sum_for_day = Bluecap.redis.bitcount(key_name) || 0

    if not @cohort.total.zero?
      engagement_for_day = (sum_for_day.to_f / @cohort.total)
    else
      engagement_for_day = 0.to_f
    end
    engagement_for_day *= 100.0
    engagement_for_day.round(2)

    results[date.strftime('%Y%m%d')] = engagement_for_day
  end

  results
end