Scoops of scopes

 

Hegedüs Zoltán

Ordinary scopes

class Foo < ActiveRecord::Base
  scope :published, -> { where(published: true) }      
  scope :published_and_commented, -> { published.where("comments_count > 0") }
end

irb(main):005:0> Foo.published
=> #<ActiveRecord::Relation [#<Foo id: 1>, #<Foo id: 5>]>

irb(main):006:0> Foo.published.joins(bar: :baz).where(id: [1,9])
=> #<ActiveRecord::Relation [#<Foo id: 1>]>

Ordinary scopes cont'd

class Foo < ActiveRecord::Base
  scope :published, -> { where(published: true) }      
  scope :published_and_commented, -> { published.where("comments_count > 0") }

  scope :wanted, -> (good_ids = nil) {
    join_clause = <<-JOINS
     LEFT JOIN (SELECT
            sessions.id AS session_id,
            articles.person_id AS person_id,
            COUNT(articles.id) AS session_activity_count
          FROM sessions
            INNER JOIN session_inclusions
              ON session_inclusions.session_id = sessions.id) tmp1 ON
                tmp1.session_id = foos.session_id
    JOINS
    relation = published
      .joins(join_clause)

    if good_ids
      relation.where(id: good_ids)
    else
      relation
    end
  }
end

irb(main):005:0> Foo.wanted([1,9])
=> #<ActiveRecord::Relation [#<Foo id: 1>]>

Ordinary scopes cont'd

SELECT
  people.*,
  routing_paths.title AS routing_path_title,
  teams.title AS team_title
FROM (SELECT
        people.id,
        people.name,
        people.team_id,
        scv.routing_path_id,
        start_date,
        end_date,
        session_description,
        session_value * session_length_ratio AS session_value,
        session_per_capita_value * session_length_ratio AS session_per_capita_value,
        COALESCE(session_activity_count, 0) AS session_activity_count,
        COALESCE(session_activity_value, 0) AS session_activity_value,
        0 AS out_of_contract_activity_value,
        0 AS out_of_contract_activity_count
      FROM "people"
        INNER JOIN "teams" ON "teams"."id" = "people"."team_id"
        JOIN (SELECT
          sessions.id AS session_id,
          sessions.description AS session_description,
          sessions.start_date,
          sessions.end_date,
          sessions.routing_path_id,
          (UPPER(daterange(sessions.start_date, sessions.end_date) * '[2019-01-01, 2019-12-31)' :: DATERANGE)
              - LOWER(daterange(sessions.start_date, sessions.end_date) *
                          '[2019-01-01, 2019-12-31)' :: DATERANGE)) :: FLOAT / (364) AS session_length_ratio,
          sessions.value_amount / 100 AS session_value,
          session_inclusions.subject_id AS person_id,
          session_inclusions.weight AS session_per_capita_value
        FROM "sessions"
          INNER JOIN "session_inclusions" ON "session_inclusions"."session_id" = "sessions"."id" AND
              "session_inclusions"."deleted_at" IS NULL
        WHERE "sessions"."deleted_at" IS NULL AND "sessions"."id" IN (SELECT "sessions"."id"
        FROM "sessions"
        WHERE "sessions"."deleted_at" IS NULL AND "sessions"."investor_id" = 851 AND (
          (sessions.start_date >= '2019-01-01' AND
              '2019-12-31' BETWEEN sessions.start_date AND sessions.end_date)
              OR (sessions.end_date <= '2019-12-31' AND
              '2019-01-01' BETWEEN sessions.start_date AND sessions.end_date)
              OR (sessions.start_date > '2019-01-01' AND sessions.end_date < '2019-12-31')
              OR (sessions.start_date < '2019-01-01' AND sessions.end_date > '2019-12-31')
        )) AND "session_inclusions"."subject_type" = 'Person') AS scv ON scv.person_id = people.id
        LEFT JOIN (SELECT
          sessions.id AS session_id,
          articles.person_id AS person_id,
          sessions.routing_path_id,
          SUM(articles.value_amount) / 100 AS session_activity_value,
          COUNT(articles.id) AS session_activity_count
        FROM "sessions"
          INNER JOIN "session_inclusions" ON "session_inclusions"."session_id" = "sessions"."id" AND
              "session_inclusions"."deleted_at" IS NULL
          JOIN articles
            ON session_inclusions.subject_id = articles.person_id AND
              articles.status IN ('granted', 'not_attend')
          JOIN activities
            ON articles.activity_id = activities.id
              AND activities.routing_path_id = sessions.routing_path_id
              AND activities.deleted_at IS NULL
              AND activities.aggregate_status = 'consumed'
              AND activities.start_date BETWEEN sessions.start_date AND sessions.end_date
              AND activities.classification_id IN (SELECT classification_id
          FROM session_classifications
          WHERE session_classifications.session_id = sessions.id
              AND session_classifications.deleted_at IS NULL)
        WHERE "sessions"."deleted_at" IS NULL AND "sessions"."id" IN (SELECT "sessions"."id"
        FROM "sessions"
        WHERE "sessions"."deleted_at" IS NULL AND "sessions"."investor_id" = 851 AND (
          (sessions.start_date >= '2019-01-01' AND
              '2019-12-31' BETWEEN sessions.start_date AND sessions.end_date)
              OR (sessions.end_date <= '2019-12-31' AND
              '2019-01-01' BETWEEN sessions.start_date AND sessions.end_date)
              OR (sessions.start_date > '2019-01-01' AND sessions.end_date < '2019-12-31')
              OR (sessions.start_date < '2019-01-01' AND sessions.end_date > '2019-12-31')
        )) AND "session_inclusions"."subject_type" = 'Person'
        LEFT JOIN (SELECT
          SUM(session_activity_value) AS session_activity_value,
          SUM(session_activity_count) AS session_activity_count,
          scv.routing_path_id,
          people.id AS person_id
        FROM "people"
          INNER JOIN "teams" ON "teams"."id" = "people"."team_id"
          JOIN (SELECT
            sessions.id AS session_id,
            sessions.description AS session_description,
            sessions.start_date,
            sessions.end_date,
            sessions.routing_path_id,
            (UPPER(
                daterange(sessions.start_date, sessions.end_date) * '[2019-01-01, 2019-12-31)' :: DATERANGE) -
                LOWER(daterange(sessions.start_date, sessions.end_date) *
                          '[2019-01-01, 2019-12-31)' :: DATERANGE)) :: FLOAT / (364) AS session_length_ratio,
            sessions.value_amount / 100 AS session_value,
            session_inclusions.subject_id AS person_id,
            session_inclusions.weight AS session_per_capita_value
          FROM "sessions"
            INNER JOIN "session_inclusions"
              ON "session_inclusions"."session_id" = "sessions"."id" AND
                "session_inclusions"."deleted_at" IS NULL
          WHERE "sessions"."deleted_at" IS NULL AND "sessions"."id" IN (SELECT "sessions"."id"
          FROM "sessions"
          WHERE "sessions"."deleted_at" IS NULL AND "sessions"."investor_id" = 851 AND (
            (sessions.start_date >= '2019-01-01' AND
                '2019-12-31' BETWEEN sessions.start_date AND sessions.end_date)
                OR (sessions.end_date <= '2019-12-31' AND
                '2019-01-01' BETWEEN sessions.start_date AND sessions.end_date)
                OR (sessions.start_date > '2019-01-01' AND sessions.end_date < '2019-12-31')
                OR (sessions.start_date < '2019-01-01' AND sessions.end_date > '2019-12-31')
          )) AND "session_inclusions"."subject_type" = 'Person') AS scv ON scv.person_id = people.id
          LEFT JOIN (SELECT
            sessions.id AS session_id,
            articles.person_id AS person_id,
            sessions.routing_path_id,
            SUM(articles.value_amount) / 100 AS session_activity_value,
            COUNT(articles.id) AS session_activity_count
          FROM "sessions"
            INNER JOIN "session_inclusions"
              ON "session_inclusions"."session_id" = "sessions"."id" AND
                "session_inclusions"."deleted_at" IS NULL
            JOIN articles
              ON session_inclusions.subject_id = articles.person_id AND
                articles.status IN ('granted', 'not_attend')
            JOIN activities
              ON articles.activity_id = activities.id
                AND activities.routing_path_id = sessions.routing_path_id
                AND activities.deleted_at IS NULL
                AND activities.aggregate_status = 'consumed'
                AND activities.start_date BETWEEN sessions.start_date AND sessions.end_date
                AND activities.classification_id IN (SELECT classification_id
            FROM session_classifications
            WHERE session_classifications.session_id = sessions.id
                AND session_classifications.deleted_at IS NULL)
          WHERE "sessions"."deleted_at" IS NULL AND "sessions"."id" IN (SELECT "sessions"."id"
          FROM "sessions"
          WHERE "sessions"."deleted_at" IS NULL AND "sessions"."investor_id" = 851 AND (
            (sessions.start_date >= '2019-01-01' AND
                '2019-12-31' BETWEEN sessions.start_date AND sessions.end_date)
                OR (sessions.end_date <= '2019-12-31' AND
                '2019-01-01' BETWEEN sessions.start_date AND sessions.end_date)
                OR (sessions.start_date > '2019-01-01' AND sessions.end_date < '2019-12-31')
                OR (sessions.start_date < '2019-01-01' AND sessions.end_date > '2019-12-31')
          )) AND "session_inclusions"."subject_type" = 'Person'
          GROUP BY sessions.id, articles.person_id) AS sav
            ON sav.person_id = people.id AND sav.session_id = scv.session_id
        WHERE "people"."id" IN (SELECT "people"."id"
        FROM "people"
          INNER JOIN "teams" ON "teams"."id" = "people"."team_id"
          INNER JOIN "offices" ON "offices"."id" = "people"."office_id"
        WHERE "offices"."firm_id" = 851)
        GROUP BY people.id, scv.routing_path_id) AS sessions
          ON sessions.person_id = people.id AND sessions.routing_path_id = rpav.routing_path_id

Enter Query objects

class Query
  class << self
    def create(**params)
      new(**params).tap(&:save)
    end
  end

  def save
    @relation = @scopes.inject(base_relation) { |relation, scope| scope.call(relation) }
  end

  def results
    @relation
  end
end

class Query::WantedFoos < Query
  def initialize(ids: nil)
    @scopes = [bars_scope]
    @scopes << id_scope(ids) if ids
  end

  private

  def base_relation
    Foo.all
  end

  def bars_scope
   join_clause = <<-JOINS
      LEFT JOIN bars ON bars.id < 5
    JOINS
    ->(relation) { relation.joins(join_clause)}
  end

  def id_scope(ids)
    ->(relation) { relation.where(id: ids)}        
  end
end

Scope objects

class BarScope
  def call(relation)
    join_clause = <<-JOINS
      LEFT JOIN bars ON bars.id < 5
    JOINS
   relation.joins(join_clause)
  end
end

class IdScope
  def initialize(ids)
    @ids = ids
  end

  def call(relation)
    relation.where(id: @ids)
  end
end

class Query::WantedFoos < Query
  def initialize(ids: nil)
    @scopes = [bars]
    @scopes << id_scope(ids) if ids
  end

  private

  def base_relation
    Foo.all
  end

  def bars
   BarScope.new
  end

  def id_scope(ids)
    IdScope.new(ids)       
  end
end

Scope objects cont'd

class BarScope
  def call(relation)
    join_clause = <<-JOINS
      LEFT JOIN bars ON bars.id < 5
    JOINS
   relation.joins(join_clause)
  end
end

class IdScope
  def initialize(ids)
    @ids = ids
  end

  def call(relation)
    relation.where(id: @ids)
  end
end

class Query::WantedFoos < Query
  def initialize(ids: nil)
    @scopes = [bars]
    @scopes << id_scope(ids) if ids
  end

  private

  def base_relation
    Foo.all
  end

  def bars
   BarScope.new
  end

  def id_scope(ids)
    IdScope.new(ids)       
  end
end
 require 'rails_helper'

describe IdScope do
  let(:scope) { described_class.new(params) }
  
  describe "#call" do
    subject { scope.call(relation) }
    let(:relation) { Foo.all }

    context "with existing id" do
      let(:params) { [Foo.first.id] }
      it "should return that foo" do
        subject.should include(Foo.first)
      end
    end
  end
end


class Query::InterestingBar < Query
  def initialize(ids: nil)
    @scopes = [id_scope]
  end

  private

  def base_relation
    Bar.all
  end

  def id_scope(ids)
    IdScope.new(ids)       
  end
end

Scope objects cont'd

class Scope::Consumption
  def initialize(investor:, date_range:, user: )
    @user = user
    @investor = investor
    @date_range = date_range

    @scopes = [managed_teams_scope]
    @scopes << subscriptions_scope
    @scopes << activities_scope
  end

  def call(relation)
    scopes.inject(relation) { |relashun, scope| scope.call(relashun) }
  end

  private

  attr_reader :scopes, :date_range, :investor, :user

  def managed_teams_scope
    if user.administrator?
      scope = Scope::ManagedTeams.new(user.person)
      ->(relation) { relation.where(people: { id: Person.where(team_id: scope.call(Team.all)) }) }
    elsif user.manager?
      ->(relation) { relation }
    else
      ->(relation) { relation.where(people: { id: user.person.id }) }
    end
  end

  def subscriptions_scope
    Scope::Consumption::Subscriptions.new(investor: investor, date_range: date_range)
  end

  def activities_scope
    Scope::Consumption::Activities.new(investor: investor)
  end
end

Thank you!

 

 

Questions?

 

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