Class: Groupdate::Magic

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(field, options) ⇒ Magic

Returns a new instance of Magic.



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# File 'lib/groupdate/magic.rb', line 5

def initialize(field, options)
  @field = field
  @options = options

  if !time_zone
    raise "Unrecognized time zone"
  end

  if field == :week and !week_start
    raise "Unrecognized :week_start option"
  end
end

Instance Attribute Details

#field ⇒ Object

Returns the value of attribute field.



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# File 'lib/groupdate/magic.rb', line 3

def field
  @field
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/groupdate/magic.rb', line 3

def options
  @options
end

Instance Method Details

#group_by(enum, &block) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 18

def group_by(enum, &block)
  series(enum.group_by{|v| v = yield(v); v ? round_time(v) : nil }, [])
end

#perform(relation, method, *args, &block) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 91

def perform(relation, method, *args, &block)
  # undo reverse since we do not want this to appear in the query
  reverse = relation.reverse_order_value
  if reverse
    relation = relation.reverse_order
  end
  order = relation.order_values.first
  if order.is_a?(String)
    parts = order.split(" ")
    reverse_order = (parts.size == 2 && parts[0].to_sym == field && parts[1].to_s.downcase == "desc")
    reverse = !reverse if reverse_order
  end

  multiple_groups = relation.group_values.size > 1

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

  count =
    begin
      Hash[ relation.send(method, *args, &block).map{|k, v| [multiple_groups ? k[0...@group_index] + [cast_method.call(k[@group_index])] + k[(@group_index + 1)..-1] : cast_method.call(k), v] } ]
    rescue NoMethodError
      raise "Be sure to install time zone support - https://github.com/ankane/groupdate#for-mysql"
    end

  series(count, 0, multiple_groups, reverse)
end

#relation(column, relation) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 22

def relation(column, relation)
  column = relation.connection.quote_table_name(column)
  time_zone = self.time_zone.tzinfo.name

  adapter_name = relation.connection.adapter_name
  query =
    case adapter_name
    when "MySQL", "Mysql2"
      case field
      when :day_of_week # Sunday = 0, Monday = 1, etc
        # use CONCAT for consistent return type (String)
        ["DAYOFWEEK(CONVERT_TZ(DATE_SUB(#{column}, INTERVAL #{day_start} HOUR), '+00:00', ?)) - 1", time_zone]
      when :hour_of_day
        ["(EXTRACT(HOUR from CONVERT_TZ(#{column}, '+00:00', ?)) + 24 - #{day_start}) % 24", time_zone]
      when :week
        ["CONVERT_TZ(DATE_FORMAT(CONVERT_TZ(DATE_SUB(#{column}, INTERVAL ((#{7 - week_start} + WEEKDAY(CONVERT_TZ(#{column}, '+00:00', ?) - INTERVAL #{day_start} HOUR)) % 7) DAY) - INTERVAL #{day_start} HOUR, '+00:00', ?), '%Y-%m-%d 00:00:00') + INTERVAL #{day_start} HOUR, ?, '+00:00')", time_zone, time_zone, time_zone]
      else
        format =
          case field
          when :second
            "%Y-%m-%d %H:%i:%S"
          when :minute
            "%Y-%m-%d %H:%i:00"
          when :hour
            "%Y-%m-%d %H:00:00"
          when :day
            "%Y-%m-%d 00:00:00"
          when :month
            "%Y-%m-01 00:00:00"
          else # year
            "%Y-01-01 00:00:00"
          end

        ["DATE_ADD(CONVERT_TZ(DATE_FORMAT(CONVERT_TZ(DATE_SUB(#{column}, INTERVAL #{day_start} HOUR), '+00:00', ?), '#{format}'), ?, '+00:00'), INTERVAL #{day_start} HOUR)", time_zone, time_zone]
      end
    when "PostgreSQL", "PostGIS"
      case field
      when :day_of_week
        ["EXTRACT(DOW from (#{column}::timestamptz AT TIME ZONE ? - INTERVAL '#{day_start} hour'))::integer", time_zone]
      when :hour_of_day
        ["EXTRACT(HOUR from #{column}::timestamptz AT TIME ZONE ? - INTERVAL '#{day_start} hour')::integer", time_zone]
      when :week # start on Sunday, not PostgreSQL default Monday
        ["(DATE_TRUNC('#{field}', (#{column}::timestamptz - INTERVAL '#{week_start} day' - INTERVAL '#{day_start}' hour) AT TIME ZONE ?) + INTERVAL '#{week_start} day' + INTERVAL '#{day_start}' hour) AT TIME ZONE ?", time_zone, time_zone]
      else
        ["(DATE_TRUNC('#{field}', (#{column}::timestamptz - INTERVAL '#{day_start} hour') AT TIME ZONE ?) + INTERVAL '#{day_start} hour') AT TIME ZONE ?", time_zone, time_zone]
      end
    else
      raise "Connection adapter not supported: #{adapter_name}"
    end

  group = relation.group(Groupdate::OrderHack.new(relation.send(:sanitize_sql_array, query), field, time_zone))
  if options[:series] == false
    group
  else
    relation =
      if time_range.is_a?(Range)
        # doesn't matter whether we include the end of a ... range - it will be excluded later
        group.where("#{column} >= ? AND #{column} <= ?", time_range.first, time_range.last)
      else
        group.where("#{column} IS NOT NULL")
      end

    # TODO do not change object state
    @group_index = group.group_values.size - 1

    Groupdate::Series.new(self, relation)
  end
end