Module: ActiveFacts::Metamodel

Defined in:

lib/activefacts/persistence/index.rb,
lib/activefacts/generate/cql.rb,
lib/activefacts/mapping/rails.rb,
lib/activefacts/persistence/tables.rb,
lib/activefacts/persistence/columns.rb,
lib/activefacts/vocabulary/metamodel.rb,
lib/activefacts/persistence/reference.rb,
lib/activefacts/vocabulary/extensions.rb,
lib/activefacts/vocabulary/verbaliser.rb,
lib/activefacts/generate/helpers/rails.rb,
lib/activefacts/persistence/foreignkey.rb,
lib/activefacts/generate/transform/surrogate.rb

Overview

:nodoc:

Defined Under Namespace

Classes: Adjective, Agent, AgentName, Aggregate, AggregateCode, Aggregation, Agreement, AllowedRange, AlternativeSet, Assimilation, Bound, Coefficient, Concept, Constraint, ConstraintShape, ContextAccordingTo, ContextAgreedBy, ContextNote, ContextNoteKind, Date, Denominator, Derivation, Diagram, Discussion, DisplayRoleNamesSetting, DomainObjectType, Enforcement, EnforcementCode, EntityType, EphemeraURL, Exponent, Facet, FacetRestriction, Fact, FactType, FactTypeShape, Frequency, Guid, ImplicationRule, ImplicationRuleName, ImplicitBooleanValueType, Instance, Length, LinkFactType, Literal, Location, ModelNoteShape, Name, Numerator, ORMDiagram, ObjectType, ObjectTypeShape, ObjectifiedFactTypeNameShape, Offset, Ordinal, Play, Population, PresenceConstraint, Pronoun, Query, Reading, ReadingShape, RegularExpression, RingConstraint, RingConstraintShape, RingType, Role, RoleDisplay, RoleNameShape, RoleRef, RoleSequence, RoleValue, RotationSetting, Scale, SetComparisonConstraint, SetComparisonRoles, SetConstraint, SetEqualityConstraint, SetExclusionConstraint, Shape, Step, Subscript, SubsetConstraint, Text, TransactionPhase, TypeInheritance, Unit, Value, ValueConstraint, ValueConstraintShape, ValueRange, ValueType, Variable, Verbaliser, Vocabulary, X, Y

Class Method Summary

• .plays_over(roles, options = :both) ⇒ Object

  Some queries must be over the proximate roles, some over the counterpart roles.

Class Method Details

.plays_over(roles, options = :both) ⇒ Object

Some queries must be over the proximate roles, some over the counterpart roles. Return the common superclass of the appropriate roles, and the actual roles

# File 'lib/activefacts/vocabulary/extensions.rb', line 915

def self.plays_over roles, options = :both   # Or :proximate, :counterpart
  # If we can stay inside this objectified FT, there's no query:
  roles = Array(roles)  # To be safe, in case we get a role collection proxy
  return nil if roles.size == 1 or
    options != :counterpart && roles.map{|role| role.fact_type}.uniq.size == 1
  proximate_sups, counterpart_sups, obj_sups, counterpart_roles, objectification_roles =
    *roles.inject(nil) do |d_c_o, role|
      object_type = role.object_type
      fact_type = role.fact_type

      proximate_role_supertypes = object_type.supertypes_transitive

      # A role in an objectified fact type may indicate either the objectification or the counterpart player.
      # This could be ambiguous. Figure out both and prefer the counterpart over the objectification.
      counterpart_role_supertypes =
        if fact_type.all_role.size > 2
          possible_roles = fact_type.all_role.select{|r| d_c_o && d_c_o[1].include?(r.object_type) }
          if possible_roles.size == 1 # Only one candidate matches the types of the possible variables
            counterpart_role = possible_roles[0]
            d_c_o[1]  # No change
          else
            # puts "#{constraint_type} #{name}: Awkward, try counterpart-role query on a >2ary '#{fact_type.default_reading}'"
            # Try all roles; hopefully we don't have two roles with a matching candidate here:
            # Find which role is compatible with the existing supertypes, if any
            if d_c_o
              st = nil
              counterpart_role =
                fact_type.all_role.detect{|r| ((st = r.object_type.supertypes_transitive) & d_c_o[1]).size > 0}
              st
            else
              counterpart_role = nil  # This can't work, we don't have any basis for a decision (must be objectification)
              []
            end
            #fact_type.all_role.map{|r| r.object_type.supertypes_transitive}.flatten.uniq
          end
        else
          # Get the supertypes of the counterpart role (care with unaries):
          ftr = role.fact_type.all_role.to_a
          (counterpart_role = ftr[0] == role ? ftr[-1] : ftr[0]).object_type.supertypes_transitive
        end

      if fact_type.entity_type
        objectification_role_supertypes =
          fact_type.entity_type.supertypes_transitive+object_type.supertypes_transitive
        objectification_role = role.link_fact_type.all_role.single # Find the phantom role here
      else
        objectification_role_supertypes = counterpart_role_supertypes
        objectification_role = counterpart_role
      end

      if !d_c_o
        d_c_o = [proximate_role_supertypes, counterpart_role_supertypes, objectification_role_supertypes, [counterpart_role], [objectification_role]]
        #puts "role player supertypes starts #{d_c_o.map{|dco| dco.map(&:name).inspect}*' or '}"
      else
        #puts "continues #{[proximate_role_supertypes, counterpart_role_supertypes, objectification_role_supertypes]map{|dco| dco.map(&:name).inspect}*' or '}"
        d_c_o[0] &= proximate_role_supertypes
        d_c_o[1] &= counterpart_role_supertypes
        d_c_o[2] &= objectification_role_supertypes
        d_c_o[3] << (counterpart_role || objectification_role)
        d_c_o[4] << (objectification_role || counterpart_role)
      end
      d_c_o
    end # inject

  # Discount a subtype step over an object type that's not a player here,
  # if we can use an objectification step to an object type that is:
  if counterpart_sups.size > 0 && obj_sups.size > 0 && counterpart_sups[0] != obj_sups[0]
    debug :query, "ambiguous query, could be over #{counterpart_sups[0].name} or #{obj_sups[0].name}"
    if !roles.detect{|r| r.object_type == counterpart_sups[0]} and roles.detect{|r| r.object_type == obj_sups[0]}
      debug :query, "discounting #{counterpart_sups[0].name} in favour of direct objectification"
      counterpart_sups = []
    end
  end

  # Choose the first entry in the first non-empty supertypes list:
  if options != :counterpart && proximate_sups[0]
    [ proximate_sups[0], roles ]
  elsif !counterpart_sups.empty?
    [ counterpart_sups[0], counterpart_roles ]
  else
    [ obj_sups[0], objectification_roles ]
  end
end