Module: NoFlyList::TaggableRecord::Query::MysqlStrategy

Extended by:
BaseStrategy
Defined in:
lib/no_fly_list/taggable_record/query/mysql_strategy.rb

Class Method Summary collapse

Methods included from BaseStrategy

case_insensitive_where

Class Method Details

.define_query_methods(setup) ⇒ Object 



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# File 'lib/no_fly_list/taggable_record/query/mysql_strategy.rb', line 11

def define_query_methods(setup)
  context = setup.context
  taggable_klass = setup.taggable_klass
  tagging_klass = setup.tagging_class_name.constantize
  tagging_table = tagging_klass.arel_table # Arel
  tag_klass = setup.tag_class_name.constantize
  tag_table = tag_klass.arel_table
  singular_name = context.to_s.singularize

  taggable_klass.class_eval do
    # Find records with any of the specified tags
    scope "with_any_#{context}", lambda { |*tags|
      tags = tags.flatten.compact.uniq
      return none if tags.empty?

      query = Arel::SelectManager.new(self)
                                 .from(table_name)
                                 .project(arel_table[primary_key])
                                 .distinct
                                 .join(tagging_table).on(tagging_table[:taggable_id].eq(arel_table[primary_key]))
                                 .join(tag_table).on(tag_table[:id].eq(tagging_table[:tag_id]))
                                 .where(tagging_table[:context].eq(singular_name))
                                 .where(tag_table[:name].in(tags))

      where(arel_table[primary_key].in(query))
    }

    scope "with_all_#{context}", lambda { |*tags|
      tags = tags.flatten.compact.uniq
      return none if tags.empty?

      count_function = Arel::Nodes::NamedFunction.new(
        "COUNT",
        [ Arel::Nodes::NamedFunction.new("DISTINCT", [ tag_table[:name] ]) ]
      )

      query = Arel::SelectManager.new(self)
                                 .from(table_name)
                                 .project(arel_table[primary_key])
                                 .join(tagging_table).on(tagging_table[:taggable_id].eq(arel_table[primary_key]))
                                 .join(tag_table).on(tag_table[:id].eq(tagging_table[:tag_id]))
                                 .where(tagging_table[:context].eq(singular_name))
                                 .where(tag_table[:name].in(tags))
                                 .group(arel_table[primary_key])
                                 .having(count_function.eq(tags.size))

      where(arel_table[primary_key].in(query))
    }

    # Find records without any of the specified tags
    scope "without_any_#{context}", lambda { |*tags|
      tags = tags.flatten.compact.uniq
      return all if tags.empty?

      subquery = joins(tagging_table)
                 .where(tagging_table[:context].eq(singular_name))
                 .where(tagging_table.name => { context: singular_name })
                 .where(tag_table.name => { name: tags })
                 .select(primary_key)

      where("#{table_name}.#{primary_key} NOT IN (?)", subquery)
    }

    # Find records without any tags
    scope "without_#{context}", lambda {
      subquery = if setup.polymorphic
                   setup.tagging_class_name.constantize
                        .where(context: singular_name)
                        .where(taggable_type: name)
                        .select(:taggable_id)
      else
                   setup.tagging_class_name.constantize
                        .where(context: singular_name)
                        .select(:taggable_id)
      end

      where("#{table_name}.#{primary_key} NOT IN (?)", subquery)
    }

    # Find records with exactly these tags
    scope "with_exact_#{context}", lambda { |*tags|
      tags = tags.flatten.compact.uniq

      if tags.empty?
        send("without_#{context}")
      else
        Arel::Nodes::NamedFunction.new(
          "COUNT",
          [ Arel::Nodes::NamedFunction.new("DISTINCT", [ tag_table[:id] ]) ]
        )

        # Build the query for records having exactly the tags
        all_tags_query = select(arel_table[primary_key])
                         .joins("INNER JOIN #{tagging_table.name} ON #{tagging_table.name}.taggable_id = #{table_name}.#{primary_key}")
                         .joins("INNER JOIN #{tag_table.name} ON #{tag_table.name}.id = #{tagging_table.name}.tag_id")
                         .where("#{tagging_table.name}.context = ?", context.to_s.singularize)
                         .where("#{tag_table.name}.name IN (?)", tags)
                         .group(arel_table[primary_key])
                         .having("COUNT(DISTINCT #{tag_table.name}.id) = ?", tags.size)

        # Build query for records with other tags
        other_tags_query = select(arel_table[primary_key])
                           .joins("INNER JOIN #{tagging_table.name} ON #{tagging_table.name}.taggable_id = #{table_name}.#{primary_key}")
                           .joins("INNER JOIN #{tag_table.name} ON #{tag_table.name}.id = #{tagging_table.name}.tag_id")
                           .where("#{tagging_table.name}.context = ?", context.to_s.singularize)
                           .where("#{tag_table.name}.name NOT IN (?)", tags)

        # Combine queries
        where("#{table_name}.#{primary_key} IN (?)", all_tags_query)
          .where("#{table_name}.#{primary_key} NOT IN (?)", other_tags_query)
      end
    }
  end
end