Module: DataMapper::Resource

Extended by:
Deprecate
Includes:
Assertions
Defined in:
lib/dm-core/resource.rb,
lib/dm-core/backwards.rb,
lib/dm-core/resource/persistence_state.rb,
lib/dm-core/resource/persistence_state/clean.rb,
lib/dm-core/resource/persistence_state/dirty.rb,
lib/dm-core/resource/persistence_state/deleted.rb,
lib/dm-core/resource/persistence_state/immutable.rb,
lib/dm-core/resource/persistence_state/persisted.rb,
lib/dm-core/resource/persistence_state/transient.rb

Defined Under Namespace

Classes: PersistenceState

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Deprecate

deprecate

Methods included from Assertions

#assert_kind_of

Class Method Details

.included(model) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Makes sure a class gets all the methods when it includes Resource

Note that including this module into an anonymous class will leave the model descendant tracking mechanism with no possibility to reliably track the anonymous model across code reloads. This means that DescendantSet will currently leak memory in scenarios where anonymous models are reloaded multiple times (as is the case in dm-rails development mode for example).


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# File 'lib/dm-core/resource.rb', line 55

def self.included(model)
  model.extend Model
  super
end

Instance Method Details

#<=>(other) ⇒ Integer

Compares two Resources to allow them to be sorted

Parameters:

  • other (Resource) —

    The other Resource to compare with

Returns:

  • (Integer) —

    Return 0 if Resources should be sorted as the same, -1 if the other Resource should be after self, and 1 if the other Resource should be before self


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# File 'lib/dm-core/resource.rb', line 491

def <=>(other)
  model = self.model
  unless other.kind_of?(model.base_model)
    raise ArgumentError, "Cannot compare a #{other.class} instance with a #{model} instance"
  end
  model.default_order(repository_name).each do |direction|
    cmp = direction.get(self) <=> direction.get(other)
    return cmp if cmp.nonzero?
  end
  0
end

#==(other) ⇒ Boolean

Compares another Resource for equivalency

Resource is equivalent to other if they are the same object (identical object_id) or all of their attribute are equivalent

Parameters:

  • other (Resource) —

    the other Resource to compare with

Returns:

  • (Boolean) —

    true if they are equivalent, false if not


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# File 'lib/dm-core/resource.rb', line 474

def ==(other)
  return true if equal?(other)
  return false unless other.kind_of?(Resource) && model.base_model.equal?(other.model.base_model)
  cmp?(other, :==)
end

#after_create_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks after resource creation

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 689

def after_create_hook
  execute_hooks_for(:after, :create)
end

#after_destroy_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks after resource destruction

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 725

def after_destroy_hook
  execute_hooks_for(:after, :destroy)
end

#after_save_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks after resource saving

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 671

def after_save_hook
  execute_hooks_for(:after, :save)
end

#after_update_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks after resource updating

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 707

def after_update_hook
  execute_hooks_for(:after, :update)
end

#attribute_dirty?(name) ⇒ Boolean

Checks if an attribute has unsaved changes

Parameters:

  • name (Symbol) —

    name of attribute to check for unsaved changes

Returns:

  • (Boolean) —

    true if attribute has unsaved changes


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# File 'lib/dm-core/resource.rb', line 586

def attribute_dirty?(name)
  dirty_attributes.key?(properties[name])
end

#attribute_get(name) ⇒ Object Also known as: []

Returns the value of the attribute.

Do not read from instance variables directly, but use this method. This method handles lazy loading the attribute and returning of defaults if nessesary.

Examples:

class Foo
  include DataMapper::Resource

  property :first_name, String
  property :last_name,  String

  def full_name
    "#{attribute_get(:first_name)} #{attribute_get(:last_name)}"
  end

  # using the shorter syntax
  def name_for_address_book
    "#{last_name}, #{first_name}"
  end
end

Parameters:

  • name (Symbol) —

    name of attribute to retrieve

Returns:

  • (Object) —

    the value stored at that given attribute (nil if none, and default if necessary)


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# File 'lib/dm-core/resource.rb', line 225

def attribute_get(name)
  property = properties[name]
  persistence_state.get(property) if property
end

#attribute_loaded?(name) ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Checks if an attribute has been loaded from the repository

Examples:

class Foo
  include DataMapper::Resource

  property :name,        String
  property :description, Text,   :lazy => false
end

Foo.new.attribute_loaded?(:description)   #=> false

Returns:

  • (Boolean) —

    true if ivar name has been loaded

  • (Boolean) —

    true if ivar name has been loaded


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# File 'lib/dm-core/resource.rb', line 573

def attribute_loaded?(name)
  properties[name].loaded?(self)
end

#attribute_set(name, value) ⇒ undefined Also known as: []=

Sets the value of the attribute and marks the attribute as dirty if it has been changed so that it may be saved. Do not set from instance variables directly, but use this method. This method handles the lazy loading the property and returning of defaults if nessesary.

Examples:

class Foo
  include DataMapper::Resource

  property :first_name, String
  property :last_name,  String

  def full_name(name)
    name = name.split(' ')
    attribute_set(:first_name, name[0])
    attribute_set(:last_name, name[1])
  end

  # using the shorter syntax
  def name_from_address_book(name)
    name = name.split(', ')
    self.first_name = name[1]
    self.last_name = name[0]
  end
end

Parameters:

  • name (Symbol) —

    name of attribute to set

  • value (Object) —

    value to store

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 267

def attribute_set(name, value)
  property = properties[name]
  if property
    value = property.typecast(value)
    self.persistence_state = persistence_state.set(property, value)
  end
end

#attributes(key_on = :name) ⇒ Hash

Gets all the attributes of the Resource instance

Parameters:

  • key_on (Symbol) (defaults to: :name) —

    Use this attribute of the Property as keys. defaults to :name. :field is useful for adapters :property or nil use the actual Property object.

Returns:

  • (Hash) —

    All the attributes


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# File 'lib/dm-core/resource.rb', line 288

def attributes(key_on = :name)
  attributes = {}

  lazy_load(properties)
  fields.each do |property|
    if model.public_method_defined?(name = property.name)
      key = case key_on
        when :name  then name
        when :field then property.field
        else             property
      end

      attributes[key] = __send__(name)
    end
  end

  attributes
end

#attributes=(attributes) ⇒ Hash

Assign values to multiple attributes in one call (mass assignment)

Parameters:

  • attributes (Hash) —

    names and values of attributes to assign

Returns:

  • (Hash) —

    names and values of attributes assigned


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# File 'lib/dm-core/resource.rb', line 316

def attributes=(attributes)
  model = self.model
  attributes.each do |name, value|
    case name
      when String, Symbol
        if model.allowed_writer_methods.include?(setter = "#{name}=")
          __send__(setter, value)
        else
          raise ArgumentError, "The attribute '#{name}' is not accessible in #{model}"
        end
      when Associations::Relationship, Property
        # only call a public #typecast (e.g. on Property instances)
        if name.respond_to?(:typecast)
          value = name.typecast(value)
        end
        self.persistence_state = persistence_state.set(name, value)
    end
  end
end

#before_create_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks before resource creation

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 680

def before_create_hook
  execute_hooks_for(:before, :create)
end

#before_destroy_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks before resource destruction

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 716

def before_destroy_hook
  execute_hooks_for(:before, :destroy)
end

#before_save_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks before resource saving

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 662

def before_save_hook
  execute_hooks_for(:before, :save)
end

#before_update_hook ⇒ undefined (protected)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Method for hooking callbacks before resource updating

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 698

def before_update_hook
  execute_hooks_for(:before, :update)
end

#clean? ⇒ Boolean

Checks if the resource has no changes to save

Returns:

  • (Boolean) —

    true if the resource may not be persisted


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# File 'lib/dm-core/resource.rb', line 167

def clean?
  persistence_state.kind_of?(PersistenceState::Clean) ||
    persistence_state.kind_of?(PersistenceState::Immutable)
end

#collection ⇒ nil, Collection

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the Collection the Resource is associated with

Returns:

  • (nil) —

    nil if this is a new record

  • (Collection) —

    a Collection that self belongs to


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# File 'lib/dm-core/resource.rb', line 615

def collection
  return @_collection if @_collection || new? || readonly?
  collection_for_self
end

#collection=(collection) ⇒ nil, Collection

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Associates a Resource to a Collection

Parameters:

  • collection (Collection, nil) —

    the collection to associate the resource with

Returns:

  • (nil) —

    nil if this is a new record

  • (Collection) —

    a Collection that self belongs to


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# File 'lib/dm-core/resource.rb', line 631

def collection=(collection)
  @_collection = collection
end

#collection_for_self ⇒ Collection

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Return a collection including the current resource only

Returns:


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# File 'lib/dm-core/resource.rb', line 641

def collection_for_self
  Collection.new(query, [ self ])
end

#destroy ⇒ Boolean

Destroy the instance, remove it from the repository

Returns:

  • (Boolean) —

    true if resource was destroyed


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# File 'lib/dm-core/resource.rb', line 422

def destroy
  return true if destroyed?
  catch :halt do
    before_destroy_hook
    _destroy
    after_destroy_hook
  end
  destroyed?
end

#destroy! ⇒ Boolean

Destroy the instance, remove it from the repository, bypassing hooks

Returns:

  • (Boolean) —

    true if resource was destroyed


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# File 'lib/dm-core/resource.rb', line 438

def destroy!
  return true if destroyed?
  _destroy(false)
  destroyed?
end

#destroyed? ⇒ Boolean

Checks if this Resource instance is destroyed

Returns:

  • (Boolean) —

    true if the resource has been destroyed


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# File 'lib/dm-core/resource.rb', line 157

def destroyed?
  readonly? && !key.nil?
end

#dirty? ⇒ Boolean

Checks if the resource has unsaved changes

Returns:

  • (Boolean) —

    true if resource may be persisted


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# File 'lib/dm-core/resource.rb', line 178

def dirty?
  run_once(true) do
    dirty_self? || dirty_parents? || dirty_children?
  end
end

#dirty_attributes ⇒ Hash

Hash of attributes that have unsaved changes

Returns:

  • (Hash) —

    attributes that have unsaved changes


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# File 'lib/dm-core/resource.rb', line 596

def dirty_attributes
  dirty_attributes = {}

  original_attributes.each_key do |property|
    next unless property.respond_to?(:dump)
    dirty_attributes[property] = property.dump(property.get!(self))
  end

  dirty_attributes
end

#eql?(other) ⇒ Boolean

Compares another Resource for equality

Resource is equal to other if they are the same object (identical object_id) or if they are both of the *same model* and all of their attributes are equivalent

Parameters:

  • other (Resource) —

    the other Resource to compare with

Returns:

  • (Boolean) —

    true if they are equal, false if not


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# File 'lib/dm-core/resource.rb', line 457

def eql?(other)
  return true if equal?(other)
  instance_of?(other.class) && cmp?(other, :eql?)
end

#hash ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns hash value of the object. Two objects with the same hash value assumed equal (using eql? method)

DataMapper resources are equal when their models have the same hash and they have the same set of properties

When used as key in a Hash or Hash subclass, objects are compared by eql? and thus hash value has direct effect on lookup


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# File 'lib/dm-core/resource.rb', line 513

def hash
  model.hash ^ key.hash
end

#inspect ⇒ String

Get a Human-readable representation of this Resource instance

Foo.new   #=> #<Foo name=nil updated_at=nil created_at=nil id=nil>

Returns:

  • (String) —

    Human-readable representation of this Resource instance


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# File 'lib/dm-core/resource.rb', line 525

def inspect
  # TODO: display relationship values
  attrs = properties.map do |property|
    value = if new? || property.loaded?(self)
      property.get!(self).inspect
    else
      '<not loaded>'
    end

    "#{property.instance_variable_name}=#{value}"
  end

  "#<#{model.name} #{attrs.join(' ')}>"
end

#key ⇒ Array(Key)

Retrieve the key(s) for this resource.

This always returns the persisted key value, even if the key is changed and not yet persisted. This is done so all relations still work.

Returns:

  • (Array(Key)) —

    the key(s) identifying this resource


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# File 'lib/dm-core/resource.rb', line 118

def key
  return @_key if defined?(@_key)

  model_key = model.key(repository_name)

  key = model_key.map do |property|
    original_attributes[property] || (property.loaded?(self) ? property.get!(self) : nil)
  end

  # only memoize a valid key
  @_key = key if model_key.valid?(key)
end

#new? ⇒ Boolean

Checks if this Resource instance is new

Returns:

  • (Boolean) —

    true if the resource is new and not saved


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# File 'lib/dm-core/resource.rb', line 137

def new?
  persistence_state.kind_of?(PersistenceState::Transient)
end

#original_attributes ⇒ Hash

Hash of original values of attributes that have unsaved changes

Returns:

  • (Hash) —

    original values of attributes that have unsaved changes


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# File 'lib/dm-core/resource.rb', line 546

def original_attributes
  if persistence_state.respond_to?(:original_attributes)
    persistence_state.original_attributes.dup.freeze
  else
    {}.freeze
  end
end

#persistence_state ⇒ Resource::PersistenceState

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Get the persisted state for the resource

Returns:


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# File 'lib/dm-core/resource.rb', line 69

def persistence_state
  @_persistence_state ||= Resource::PersistenceState::Transient.new(self)
end

#persistence_state=(state) ⇒ undefined

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Set the persisted state for the resource

Parameters:

Returns:

  • (undefined) 

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# File 'lib/dm-core/resource.rb', line 81

def persistence_state=(state)
  @_persistence_state = state
end

#persistence_state? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Test if the persisted state is set

Returns:

  • (Boolean) —

    true if the persisted state is set


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# File 'lib/dm-core/resource.rb', line 91

def persistence_state?
  defined?(@_persistence_state) ? true : false
end

#query ⇒ Query

Returns a Query that will match the resource

Returns:

  • (Query) —

    Query that will match the resource


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# File 'lib/dm-core/resource.rb', line 651

def query
  repository.new_query(model, :fields => fields, :conditions => conditions)
end

#raise_on_save_failure ⇒ Boolean

Return if Resource#save should raise an exception on save failures (per-resource)

This delegates to model.raise_on_save_failure by default.

user.raise_on_save_failure  # => false

Returns:

  • (Boolean) —

    true if a failure in Resource#save should raise an exception


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# File 'lib/dm-core/resource.rb', line 15

def raise_on_save_failure
  if defined?(@raise_on_save_failure)
    @raise_on_save_failure
  else
    model.raise_on_save_failure
  end
end

#raise_on_save_failure=(raise_on_save_failure) ⇒ Boolean

Specify if Resource#save should raise an exception on save failures (per-resource)

Parameters:

  • a (Boolean) —

    boolean that if true will cause Resource#save to raise an exception

Returns:

  • (Boolean) —

    true if a failure in Resource#save should raise an exception


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# File 'lib/dm-core/resource.rb', line 32

def raise_on_save_failure=(raise_on_save_failure)
  @raise_on_save_failure = raise_on_save_failure
end

#readonly? ⇒ Boolean

Checks if this Resource instance is readonly

Returns:

  • (Boolean) —

    true if the resource cannot be persisted


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# File 'lib/dm-core/resource.rb', line 190

def readonly?
  persistence_state.kind_of?(PersistenceState::Immutable)
end

#reload ⇒ Resource

Reloads association and all child association

This is accomplished by resetting the Resource key to it's original value, and then removing all the ivars for properties and relationships. On the next access of those ivars, the resource will eager load what it needs. While this is more of a lazy reload, it should result in more consistent behavior since no cached results will remain from the initial load.

Returns:

  • (Resource) —

    the receiver, the current Resource instance


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# File 'lib/dm-core/resource.rb', line 349

def reload
  if key
    reset_key
    clear_subjects
  end

  self.persistence_state = persistence_state.rollback

  self
end

#repository ⇒ Repository

Repository this resource belongs to in the context of this collection or of the resource's class.

Returns:

  • (Repository) —

    the respository this resource belongs to, in the context of a collection OR in the instance's Model's context


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# File 'lib/dm-core/resource.rb', line 103

def repository
  # only set @_repository explicitly when persisted
  defined?(@_repository) ? @_repository : model.repository
end

#save ⇒ Boolean

Save the instance and loaded, dirty associations to the data-store

Returns:

  • (Boolean) —

    true if Resource instance and all associations were saved


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# File 'lib/dm-core/resource.rb', line 396

def save
  assert_not_destroyed(:save)
  retval = _save
  assert_save_successful(:save, retval)
  retval
end

#save! ⇒ Boolean

Save the instance and loaded, dirty associations to the data-store, bypassing hooks

Returns:

  • (Boolean) —

    true if Resource instance and all associations were saved


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# File 'lib/dm-core/resource.rb', line 409

def save!
  assert_not_destroyed(:save!)
  retval = _save(false)
  assert_save_successful(:save!, retval)
  retval
end

#saved? ⇒ Boolean

Checks if this Resource instance is saved

Returns:

  • (Boolean) —

    true if the resource has been saved


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# File 'lib/dm-core/resource.rb', line 147

def saved?
  persistence_state.kind_of?(PersistenceState::Persisted)
end

#update(attributes) ⇒ Boolean

Updates attributes and saves this Resource instance

Parameters:

  • attributes (Hash) —

    attributes to be updated

Returns:

  • (Boolean) —

    true if resource and storage state match


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# File 'lib/dm-core/resource.rb', line 369

def update(attributes)
  assert_update_clean_only(:update)
  self.attributes = attributes
  save
end

#update!(attributes) ⇒ Boolean

Updates attributes and saves this Resource instance, bypassing hooks

Parameters:

  • attributes (Hash) —

    attributes to be updated

Returns:

  • (Boolean) —

    true if resource and storage state match


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# File 'lib/dm-core/resource.rb', line 384

def update!(attributes)
  assert_update_clean_only(:update!)
  self.attributes = attributes
  save!
end

#update_attributes(attributes = {}, *allowed) ⇒ Object

Deprecated.

Deprecated API for updating attributes and saving Resource

See Also:


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# File 'lib/dm-core/resource.rb', line 41

def update_attributes(attributes = {}, *allowed)
  raise "#{model}#update_attributes is deprecated, use #{model}#update instead (#{caller.first})"
end