Class: Groupdate::Series

Inherits:
Object
  • Object
show all
Defined in:
lib/groupdate/series.rb

Instance Method Summary collapse

Constructor Details

#initialize(relation, field, column, time_zone, time_range, week_start, day_start) ⇒ Series

Returns a new instance of Series.



4
5
6
7
8
9
10
11
12
13
14
15
16
 
# File 'lib/groupdate/series.rb', line 4

def initialize(relation, field, column, time_zone, time_range, week_start, day_start)
  if time_range.is_a?(Range)
    # doesn't matter whether we include the end of a ... range - it will be excluded later
    @relation = relation.where("#{column} >= ? AND #{column} <= ?", time_range.first, time_range.last)
  else
    @relation = relation.where("#{column} IS NOT NULL")
  end
  @field = field
  @time_zone = time_zone
  @time_range = time_range
  @week_start = week_start
  @day_start = day_start
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



90
91
92
93
94
95
96
97
98
99
 
# File 'lib/groupdate/series.rb', line 90

def method_missing(method, *args, &block)
  # https://github.com/rails/rails/blob/master/activerecord/lib/active_record/relation/calculations.rb
  if ActiveRecord::Calculations.method_defined?(method)
    build_series(@relation.send(method, *args, &block))
  elsif [:joins, :includes, :where].include?(method)
    raise NoMethodError, "#{method} must come before the group_by_#{@field} method"
  else
    raise NoMethodError, "valid methods are: #{ActiveRecord::Calculations.instance_methods.join(", ")}"
  end
end

Instance Method Details

#build_series(count) ⇒ Object 



18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
 
# File 'lib/groupdate/series.rb', line 18

def build_series(count)
  utc = ActiveSupport::TimeZone["UTC"]

  cast_method =
    case @field
    when "day_of_week", "hour_of_day"
      lambda{|k| k.to_i }
    else
      lambda{|k| (k.is_a?(String) ? utc.parse(k) : k.to_time).in_time_zone(@time_zone) }
    end

  count = Hash[ count.map{|k, v| [cast_method.call(k), v] } ]

  series =
    case @field
    when "day_of_week"
      0..6
    when "hour_of_day"
      0..23
    else
      time_range =
        if @time_range.is_a?(Range)
          @time_range
        else
          # use first and last values
          sorted_keys = count.keys.sort
          sorted_keys.first..sorted_keys.last
        end

      if time_range.first
        # determine start time
        time = time_range.first.to_time.in_time_zone(@time_zone) - @day_start.hours
        starts_at =
          case @field
          when "second"
            time.change(:usec => 0)
          when "minute"
            time.change(:sec => 0)
          when "hour"
            time.change(:min => 0)
          when "day"
            time.beginning_of_day
          when "week"
            # same logic as MySQL group
            weekday = (time.wday - 1) % 7
            (time - ((7 - @week_start + weekday) % 7).days).midnight
          when "month"
            time.beginning_of_month
          else # year
            time.beginning_of_year
          end

        starts_at += @day_start.hours
        series = [starts_at]

        step = 1.send(@field)

        while time_range.cover?(series.last + step)
          series << series.last + step
        end

        series
      else
        []
      end
    end

  Hash[series.map do |k|
    [k, count[k] || 0]
  end]
end