Class: Spira::Base

Inherits:
Object
  • Object
show all
Extended by:
ActiveModel::Callbacks, ActiveModel::Naming, Reflections, Resource
Includes:
ActiveModel::Conversion, ActiveModel::Dirty, ActiveModel::Serialization, RDF, RDF::Enumerable, RDF::Queryable, Persistence, Serialization, Types, Utils, Validations
Defined in:
lib/spira/base.rb

Overview

Spira::Base aims to perform similar to ActiveRecord::Base You should inherit your models from it.

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Resource

configure, has_many, property

Methods included from Reflections

reflect_on_association, reflections

Methods included from Serialization

#encode_with, #init_with

Methods included from Validations

#save, #save!, #valid?

Methods included from Persistence

#count, #destroy, #destroy!, #destroyed?, #each, #new_record?, #persisted?, #save, #save!, #update_attributes

Methods included from Utils

#rename!

Constructor Details

#initialize(props = {}, options = {}) {|self| ... } ⇒ Base

Initialize a new Spira::Base instance of this resource class using a new blank node subject. Accepts a hash of arguments for initial attributes. To use a URI or existing blank node as a subject, use the `.for` method on the subclass instead.

Examples:

class Person < Spira::Base; end
bob = Person.for("bob")

Parameters:

  • props (Hash{Symbol => Any}) (defaults to: {})

    Default attributes for this instance

Yields:

  • (self)

    Executes a given block

Yield Parameters:

  • self (self)

    The newly created instance

See Also:


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# File 'lib/spira/base.rb', line 122

def initialize(props = {}, options = {})
  @subject = props.delete(:_subject) || RDF::Node.new
  @attrs = {}

  reload props

  yield self if block_given?
end

Class Attribute Details

.propertiesObject (readonly)

Returns the value of attribute properties.


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# File 'lib/spira/base.rb', line 36

def properties
  @properties
end

.reflectionsObject (readonly)

Returns the value of attribute reflections.


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# File 'lib/spira/base.rb', line 36

def reflections
  @reflections
end

Instance Attribute Details

#subjectRDF::URI (readonly)

This instance's URI.

Returns:


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# File 'lib/spira/base.rb', line 33

def subject
  @subject
end

Class Method Details

.base_uriVoid

The base URI for this class. Attempts to create instances for non-URI objects will be appended to this base URI.

Returns:

  • (Void)

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# File 'lib/spira/base.rb', line 47

def base_uri
  # should be redefined in children, if required
  # see also Spira::Resource.configure :base_uri option
  nil
end

.default_vocabularyVoid

The default vocabulary for this class. Setting a default vocabulary will allow properties to be defined without a `:predicate` option. Predicates will instead be created by appending the property name to the given string.

Returns:

  • (Void)

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# File 'lib/spira/base.rb', line 60

def default_vocabulary
  # should be redefined in children, if required
  # see also Spira::Resource.configure :default_vocabulary option
  nil
end

.serialize(node, options = {}) ⇒ Object


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# File 'lib/spira/base.rb', line 66

def serialize(node, options = {})
  if node.respond_to?(:subject)
    node.subject
  elsif node.respond_to?(:blank?) && node.blank?
    nil
  else
    raise TypeError, "cannot serialize #{node.inspect} as a Spira resource"
  end
end

.typesObject


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# File 'lib/spira/base.rb', line 38

def types
  Set.new
end

.unserialize(value, options = {}) ⇒ Object


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# File 'lib/spira/base.rb', line 76

def unserialize(value, options = {})
  if value.respond_to?(:blank?) && value.blank?
    nil
  else
    # Spira resources are instantiated as "promised"
    # to avoid instantiation loops in case of resource-to-resource relations.
    promise { instantiate_record(value) }
  end
end

Instance Method Details

#==(other) ⇒ Object

Compare this instance with another instance. The comparison is done on an RDF level, and will work across subclasses as long as the attributes are the same.


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# File 'lib/spira/base.rb', line 196

def ==(other)
  # TODO: define behavior for equality on subclasses.
  # TODO: should we compare attributes here?
  if self.class == other.class
    subject == other.uri
  elsif other.is_a?(RDF::Enumerable)
    self.isomorphic_with?(other)
  else
    false
  end
end

#assign_attributes(attrs) ⇒ Object

Assign attributes to the resource without persisting it.


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# File 'lib/spira/base.rb', line 283

def assign_attributes(attrs)
  attrs.each do |name, value|
    attribute_will_change!(name.to_s)
    send "#{name}=", value
  end
end

#attributesObject

Returns the attributes


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# File 'lib/spira/base.rb', line 132

def attributes
  @attrs
end

#copy(new_subject) ⇒ Spira::Base

Returns a new instance of this class with the new subject instead of self.subject

Parameters:

  • new_subject (RDF::Resource)

Returns:


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# File 'lib/spira/base.rb', line 266

def copy(new_subject)
  self.class.new(@attrs.merge(_subject: new_subject))
end

#copy!(new_subject) ⇒ Spira::Base, String

Returns a new instance of this class with the new subject instead of self.subject after saving the new copy to the repository.

Parameters:

  • new_subject (RDF::Resource)

Returns:


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# File 'lib/spira/base.rb', line 276

def copy!(new_subject)
  copy(new_subject).save!
end

#freezeObject

Freeze the attributes hash such that associations are still accessible, even on destroyed records.


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# File 'lib/spira/base.rb', line 137

def freeze
  @attrs.freeze; self
end

#frozen?Boolean

Returns true if the attributes hash has been frozen.

Returns:


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# File 'lib/spira/base.rb', line 142

def frozen?
  @attrs.frozen?
end

#idObject


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# File 'lib/spira/base.rb', line 102

def id
  new_record? ? nil : subject.path.split(/\//).last
end

#inspectObject

A developer-friendly view of this projection


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# File 'lib/spira/base.rb', line 186

def inspect
  "<#{self.class}:#{self.object_id} @subject: #{@subject}>"
end

#node?true, false

Returns true if the subject associated with this instance is a blank node.

Returns:

  • (true, false)

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# File 'lib/spira/base.rb', line 247

def node?
  subject.node?
end

#reload(props = {}) ⇒ Object

Assign all attributes from the given hash.


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# File 'lib/spira/base.rb', line 168

def reload(props = {})
  reset_changes
  super
  assign_attributes(props)
  self
end

#respond_to?(*args) ⇒ Boolean

Returns true for :to_uri if this instance's subject is a URI, and false if it is not. Returns true for :to_node if this instance's subject is a Node, and false if it is not. Calls super otherwise.

Returns:


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# File 'lib/spira/base.rb', line 213

def respond_to?(*args)
  case args[0]
  when :to_uri
    subject.respond_to?(:to_uri)
  when :to_node
    subject.node?
  else
    super(*args)
  end
end

#to_nodeRDF::Node

Returns the Node subject of this resource, if available. If this resource's subject is a URI, raises a NoMethodError.

Returns:

Raises:

  • (NoMethodError)

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# File 'lib/spira/base.rb', line 257

def to_node
  subject.node? ? subject : (raise NoMethodError, "No such method: :to_uri (this instance's subject is not a URI)")
end

#to_rdfRDF::Enumerable

Returns the RDF representation of this resource.

Returns:

  • (RDF::Enumerable)

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# File 'lib/spira/base.rb', line 179

def to_rdf
  self
end

#to_uriRDF::URI

Returns the URI representation of this resource, if available. If this resource's subject is a BNode, raises a NoMethodError.

Returns:

Raises:

  • (NoMethodError)

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# File 'lib/spira/base.rb', line 239

def to_uri
  uri || (raise NoMethodError, "No such method: :to_uri (this instance's subject is not a URI)")
end

#typenil, RDF::URI

The `RDF.type` associated with this class.

This just takes a first type from “types” list, so make sure you know what you're doing if you use it.

Returns:

  • (nil, RDF::URI)

    The RDF type associated with this instance's class.


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# File 'lib/spira/base.rb', line 153

def type
  self.class.type
end

#typesnil, RDF::URI

All `RDF.type` nodes associated with this class.

Returns:

  • (nil, RDF::URI)

    The RDF type associated with this instance's class.


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# File 'lib/spira/base.rb', line 161

def types
  self.class.types
end

#uriRDF::URI?

Returns the RDF::URI associated with this instance if this instance's subject is an RDF::URI, and nil otherwise.

Returns:


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# File 'lib/spira/base.rb', line 229

def uri
  subject.respond_to?(:to_uri) ? subject : nil
end