Class: ActiveFacts::Metamodel::ValueType

Inherits:
DomainObjectType show all
Defined in:
lib/activefacts/persistence/columns.rb,
lib/activefacts/generate/cql.rb,
lib/activefacts/persistence/index.rb,
lib/activefacts/persistence/tables.rb,
lib/activefacts/vocabulary/metamodel.rb,
lib/activefacts/vocabulary/extensions.rb,
lib/activefacts/generate/transform/surrogate.rb

Overview

The ValueType class is defined in the metamodel; full documentation is not generated. This section shows the features relevant to relational Persistence.

Direct Known Subclasses

ImplicitBooleanValueType

Instance Attribute Summary

Attributes inherited from ObjectType

#injected_surrogate_role, #tentative

Instance Method Summary collapse

Methods inherited from ObjectType

#add_surrogate, #all_absorbed_foreign_key_reference_path, #clear_indices, #clear_references, #columns, #definitely_not_table, #definitely_table, #foreign_keys, #foreign_keys_to, #has_references, #indices, #populate_columns, #populate_indices, #populate_reference, #populate_references, #probably_not_table, #probably_table, #rails_class_name, #rails_name, #rails_singular_name, #references_from, #references_to, #show_tabular

Instance Method Details

#absorbed_via ⇒ Object

:nodoc:



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# File 'lib/activefacts/persistence/tables.rb', line 21

def absorbed_via  #:nodoc:
  # ValueTypes aren't absorbed in the way EntityTypes are
  nil
end

#all_columns(excluded_supertypes) ⇒ Object

When absorbing this ValueType, what columns must be absorbed? This must be a fresh copy, because the columns will have References prepended.



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# File 'lib/activefacts/persistence/columns.rb', line 271

def all_columns(excluded_supertypes)    #:nodoc:
  columns = []
  debug :columns, "All Columns for #{name}" do
    if is_table
      self_value_reference
    else
      columns << ActiveFacts::Persistence::Column.new
    end
    references_from.each do |ref|
      debug :columns, "Columns absorbed via #{ref}" do
        columns += ref.columns({})
      end
    end
  end
  columns
end

#as_cql ⇒ Object 



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# File 'lib/activefacts/generate/cql.rb', line 617

def as_cql
  parameters =
    [ length != 0 || scale != 0 ? length : nil,
      scale != 0 ? scale : nil
    ].compact
  parameters = parameters.length > 0 ? "("+parameters.join(",")+")" : ""

  "#{name
    } #{
      (is_independent ? '[independent] ' : '')
    }is written as #{
      (supertype || self).name
    }#{
      parameters
    }#{
      unit && " "+unit.name
    }#{
	    concept.all_context_note_as_relevant_concept.map do |cn|
 cn.verbalise
	    end.join("\n")
	  }#{
      value_constraint && " "+value_constraint.describe
    };"
end

#identifier_columns ⇒ Object

The identifier_columns for a ValueType can only ever be the self-value role that was injected



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# File 'lib/activefacts/persistence/columns.rb', line 241

def identifier_columns
  debug :columns, "Identifier Columns for #{name}" do
    raise "Illegal call to identifier_columns for absorbed ValueType #{name}" unless is_table
    if isr = injected_surrogate_role
      columns.select{|column| column.references[0].from_role == isr }
    else
      columns.select{|column| column.references[0] == self_value_reference}
    end
  end
end

#inject_surrogate ⇒ Object 



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# File 'lib/activefacts/generate/transform/surrogate.rb', line 73

def inject_surrogate
	debug :transform_surrogate, "Adding surrogate ID to Value Type #{name}"
	add_surrogate('Auto Counter', 'ID')
end

#is_auto_assigned ⇒ Object

Is this ValueType auto-assigned on first save to the database?



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# File 'lib/activefacts/persistence/tables.rb', line 50

def is_auto_assigned
  # REVISIT: Find a better way to determine AutoCounters (ValueType unary role?)
  type = self
  type = type.supertype while type.supertype
  type.name =~ /^Auto/
end

#is_table ⇒ Object

Returns true if this ValueType is a table



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# File 'lib/activefacts/persistence/tables.rb', line 27

def is_table
  return @is_table if @is_table != nil

  # Always a table if marked so:
  if is_independent
    debug :absorption, "ValueType #{name} is declared independent"
    @tentative = false
    return @is_table = true
  end

  # Only a table if it has references (to another ValueType)
  if !references_from.empty? && !is_auto_assigned
    debug :absorption, "#{name} is a table because it has #{references_from.size} references to it"
    @is_table = true
  else
    @is_table = false
  end
  @tentative = false

  @is_table
end

#needs_surrogate ⇒ Object 



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# File 'lib/activefacts/generate/transform/surrogate.rb', line 68

def needs_surrogate
	supertype_names = supertypes_transitive.map(&:name)
	!(supertype_names.include?('Auto Counter') or supertype_names.include?('Guid') or supertype_names.include?('ID'))
end

#reference_columns(excluded_supertypes) ⇒ Object

When creating a foreign key to this ValueType, what columns must we include? This must be a fresh copy, because the columns will have References prepended



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# File 'lib/activefacts/persistence/columns.rb', line 254

def reference_columns(excluded_supertypes)  #:nodoc:
  debug :columns, "Reference Columns for #{name}" do
    if is_table
      if isr = injected_surrogate_role
        ref_from = references_from.detect{|ref| ref.from_role == isr}
        [ActiveFacts::Persistence::Column.new(ref_from)]
      else
        [ActiveFacts::Persistence::Column.new(self_value_reference)]
      end
    else
      [ActiveFacts::Persistence::Column.new]
    end
  end
end

#self_index ⇒ Object 



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# File 'lib/activefacts/persistence/index.rb', line 93

def self_index
	ActiveFacts::Persistence::Index.new(
	  nil,	  # The implied uniqueness constraint is not created
	  self,	  # ValueType being indexed
	  self,	  # Absorbed object being indexed
	  columns.select{|c| c.references[0].is_self_value},
	  injected_surrogate_role ? false : true
	)
end

#self_value_reference ⇒ Object

If someone asks for this, it’s because it’s needed, so create it.



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# File 'lib/activefacts/persistence/columns.rb', line 289

def self_value_reference  #:nodoc:
  # Make a reference for the self-value column
  @self_value_reference ||= ActiveFacts::Persistence::Reference.new(self, nil).tabulate
end

#subtypes ⇒ Object 



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# File 'lib/activefacts/vocabulary/extensions.rb', line 258

def subtypes
  all_value_type_as_supertype
end

#subtypes_transitive ⇒ Object 



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# File 'lib/activefacts/vocabulary/extensions.rb', line 262

def subtypes_transitive
  [self] + subtypes.map{|st| st.subtypes_transitive}.flatten
end

#supertypes_transitive ⇒ Object 



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# File 'lib/activefacts/vocabulary/extensions.rb', line 254

def supertypes_transitive
  [self] + (supertype ? supertype.supertypes_transitive : [])
end