AggtiveRecord

NOTE: This gem is not really functional yet. I just like to commit things good and early.

An attempt to formalize the description of common aggregations across timestamped records.

I wrote this gem because I found myself writing, over and over again, these kind of ActiveRecord scope:

To get the number of messages sent in the last two weeks:

Message.where('sent_at >= ?', 14.days.ago).count

To get the rate of messages per week:

Message.count * SECONDS_PER_WEEK / (Message.order('sent_at ASC').last - Message.order('sent_at ASC').first)

Or how about the rate per week for messages sent in the past month (because it's interesting to know if someone has sent more messages recently)?

Message.where('sent_at >= ?', 1.month.ago) * SECONDS_PER_WEEK / (Time.now - 1.month.ago)

This is easily enough to formalize in one application, but I figured maybe it'd be useful to have a convention for every app that I ever do that tries to aggregate records by time.

Let's make some meta-magic

So for the first example, for counting messages in the past two weeks, something like:

Message.count_past_14_days

OK, admittedly that's not much nicer than the standard ActiveRecord chain. But for the second example, it could be simplified to this:

Message.rate_per_week

And for the third example:

Message.rate_during_past_month_per_week

AggtiveRecord is an extension that can be applied to ActiveRecord. Maybe you'll find it useful, maybe not.

This gem takes some inspiration from the highly useful groupdate.

Message.count_during_past_year_per_day


Message.group_by_day.where('sent_at >= ?' 1.year.ago)

Interaction with :has_many

Obviously, this is just speculative

@person.rate_of_messages_per_day

@person.messages_count_during_past_year_per_day

@person.messages_rate_per_day_during_past_year

@person.messages_count_in_past_year_by_day
@person.messages_count_in_past_year_by_day

Message.count_during_past_year

A standard verbose call:

@person.sum_word_count_from_messages_during_past_year_by_day

Under the hood query:

@person.egg.
  collate(:sum, :word_count).
  from(:messages).
  in(:past_year).
  by(:day)

Which translates to this in ActiveRecord:

@person.messages.
  where('sent_at >= ?', 1.year.ago).
  group_by_day(:sent_at).
  sum(:word_count)

Result types

Scalars

@messages.count_during_past_year
@messages.rate_per_day_during_past_year
@messages.average_per_day_of_word_count_during_past_year
@messages.sum_of_word_count_during_past_year

Arrays

similar to groupdate

@messages.count_in_past_year_by_day
@messages.count_in_past_year_by_weekday
@messages.count_in_past_year_by_dayhour
@messages.count_in_past_year_by_hour

@messages.rate_per_hour_in_past_year_by_day
@messages.average_per_day_of_word_count_during_past_year_by_month
@messages.sum_of_word_count_during_past_year_by_day

Custom time periods

@messages.count_during_year(year: 2010)
@messages.count_during_years(years: 2008..2012)
@messages.count_during_day(day: '2012-12-01')
@messages.count_during_year_by_week(year: 2010, timezone: 'PST', first_day: 'Sunday')

count

rate_per average_per, of_numeric_value

sum, of_numeric_value

list_of_proper_nouns_during_past_year

counted_list_of_proper_nouns_during_past_year

aggtive_record

Development