Class: Rumbly::Model::Relationship

Inherits:
Object
  • Object
show all
Extended by:
Abstract
Defined in:
lib/rumbly/model/relationship.rb

Overview

This is an abstract class that represents a (one-way) relationship between two classes within an MVC application. Object mapper-specific implementations should subclass this class and implement the following methods: type, source, target, name, multiplicity, through, and navigable.

According to the UML spec, generalizations don’t really have a name or a multiplicity, so these attributes should should be nil for this Relationship type; navigable should always return true for generalizations, and the subclass should be the source, whereas the superclass should be the target.

Direct Known Subclasses

ActiveRecord::Relationship

Constant Summary collapse

ATTRIBUTES =

Attributes and default values of a Relationship

{
  type: :association, source: nil, target: nil, name: '',
  multiplicity: nil, through: nil, navigable: false
}
RELATIONSHIP_TYPES =

Valid Relationship types

[
  :dependency, :association, :aggregation, :composition, :generalization
]

Instance Method Summary collapse

Methods included from Abstract

stub_required_methods

Instance Method Details

#<=>(other) ⇒ Object

Compares two Relationship objects by first seeing if their sources or targets differ. If those are the same, then use the name, then type, then through.



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# File 'lib/rumbly/model/relationship.rb', line 39

def <=> (other)
  (source <=> other.source).nonzero? || (target <=> other.target).nonzero? ||
  (name <=> other.name).nonzero? || (type <=> other.type).nonzero? ||
  (through <=> other.through)
end

#label ⇒ Object

Returns a string that fully describes this Relationship, including its type, name, source, target, through class, and multiplicity.



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# File 'lib/rumbly/model/relationship.rb', line 47

def label
  label  = "#{type.to_s}"
  label += " '#{name}'"
  label += " from #{source.name}"
  label += " to #{target.name}"
  label += " through #{through.name}" unless through.nil?
  label += " #{multiplicity.inspect}"
end

#navigable? ⇒ Boolean

Simple question mark-style wrapper for the Relationship#navigable attribute.

Returns:

  • (Boolean) 


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# File 'lib/rumbly/model/relationship.rb', line 33

def navigable?
  navigable
end