Class: Groupdate::Magic::Relation

Inherits:
Groupdate::Magic show all
Defined in:
lib/groupdate/magic.rb

Constant Summary

Constants inherited from Groupdate::Magic

DAYS

Instance Attribute Summary

Attributes inherited from Groupdate::Magic

#group_index, #n_seconds, #options, #period

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Groupdate::Magic

#day_start, #range, #series_builder, #time_range, #time_zone, #validate_arguments, #validate_keywords, validate_period, #week_start

Constructor Details

#initialize(**options) ⇒ Relation

Returns a new instance of Relation.



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# File 'lib/groupdate/magic.rb', line 122

def initialize(**options)
  super(**options.reject { |k, _| [:default_value, :carry_forward, :last, :current].include?(k) })
  @options = options
end

Class Method Details

.generate_relation(relation, field:, **options) ⇒ Object

Raises:



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# File 'lib/groupdate/magic.rb', line 199

def self.generate_relation(relation, field:, **options)
  magic = Groupdate::Magic::Relation.new(**options)

  adapter_name = relation.connection.adapter_name
  adapter = Groupdate.adapters[adapter_name]
  raise Groupdate::Error, "Connection adapter not supported: #{adapter_name}" unless adapter

  # very important
  column = validate_column(field)
  column = resolve_column(relation, column)

  # generate ActiveRecord relation
  relation =
    adapter.new(
      relation,
      column: column,
      period: magic.period,
      time_zone: magic.time_zone,
      time_range: magic.time_range,
      week_start: magic.week_start,
      day_start: magic.day_start,
      n_seconds: magic.n_seconds
    ).generate

  # add Groupdate info
  magic.group_index = relation.group_values.size - 1
  (relation.groupdate_values ||= []) << magic

  relation
end

.process_result(relation, result, **options) ⇒ Object

allow any options to keep flexible for future



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# File 'lib/groupdate/magic.rb', line 255

def self.process_result(relation, result, **options)
  relation.groupdate_values.reverse.each do |gv|
    result = gv.perform(relation, result, default_value: options[:default_value])
  end
  result
end

.resolve_column(relation, column) ⇒ Object

resolves eagerly need to convert both where_clause (easy) and group_clause (not easy) if want to avoid this



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# File 'lib/groupdate/magic.rb', line 247

def resolve_column(relation, column)
  node = relation.send(:relation).send(:arel_columns, [column]).first
  node = Arel::Nodes::SqlLiteral.new(node) if node.is_a?(String)
  relation.connection.visitor.accept(node, Arel::Collectors::SQLString.new).value
end

.validate_column(column) ⇒ Object

basic version of Active Record disallow_raw_sql! symbol = column (safe), Arel node = SQL (safe), other = untrusted matches table.column and column



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# File 'lib/groupdate/magic.rb', line 234

def validate_column(column)
  unless column.is_a?(Symbol) || column.is_a?(Arel::Nodes::SqlLiteral)
    column = column.to_s
    unless /\A\w+(\.\w+)?\z/i.match(column)
      raise ActiveRecord::UnknownAttributeReference, "Query method called with non-attribute argument(s): #{column.inspect}. Use Arel.sql() for known-safe values."
    end
  end
  column
end

Instance Method Details

#cast_method ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 141

def cast_method
  @cast_method ||= begin
    case period
    when :minute_of_hour, :hour_of_day, :day_of_month, :day_of_year, :month_of_year
      lambda { |k| k.to_i }
    when :day_of_week
      lambda { |k| (k.to_i - 1 - week_start) % 7 }
    when :day, :week, :month, :quarter, :year
      # TODO keep as date
      if day_start != 0
        day_start_hour = day_start / 3600
        day_start_min = (day_start % 3600) / 60
        day_start_sec = (day_start % 3600) % 60
        lambda { |k| k.in_time_zone(time_zone).change(hour: day_start_hour, min: day_start_min, sec: day_start_sec) }
      else
        lambda { |k| k.in_time_zone(time_zone) }
      end
    else
      utc = ActiveSupport::TimeZone["UTC"]
      lambda { |k| (k.is_a?(String) || !k.respond_to?(:to_time) ? utc.parse(k.to_s) : k.to_time).in_time_zone(time_zone) }
    end
  end
end

#cast_result(result, multiple_groups) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 165

def cast_result(result, multiple_groups)
  new_result = {}
  result.each do |k, v|
    if multiple_groups
      k[group_index] = cast_method.call(k[group_index])
    else
      k = cast_method.call(k)
    end
    new_result[k] = v
  end
  new_result
end

#check_nils(result, multiple_groups, relation) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 188

def check_nils(result, multiple_groups, relation)
  has_nils = multiple_groups ? (result.keys.first && result.keys.first[group_index].nil?) : result.key?(nil)
  if has_nils
    if time_zone_support?(relation)
      raise Groupdate::Error, "Invalid query - be sure to use a date or time column"
    else
      raise Groupdate::Error, "Database missing time zone support for #{time_zone.tzinfo.name} - see https://github.com/ankane/groupdate#for-mysql"
    end
  end
end

#perform(relation, result, default_value:) ⇒ Object 



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# File 'lib/groupdate/magic.rb', line 127

def perform(relation, result, default_value:)
  multiple_groups = relation.group_values.size > 1

  check_nils(result, multiple_groups, relation)
  result = cast_result(result, multiple_groups)

  series_builder.generate(
    result,
    default_value: options.key?(:default_value) ? options[:default_value] : default_value,
    multiple_groups: multiple_groups,
    group_index: group_index
  )
end

#time_zone_support?(relation) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/groupdate/magic.rb', line 178

def time_zone_support?(relation)
  if relation.connection.adapter_name =~ /mysql/i
    # need to call klass for Rails < 5.2
    sql = relation.klass.send(:sanitize_sql_array, ["SELECT CONVERT_TZ(NOW(), '+00:00', ?)", time_zone.tzinfo.name])
    !relation.connection.select_all(sql).first.values.first.nil?
  else
    true
  end
end