Class: Gcloud::Datastore::Key

Inherits:
Object
  • Object
show all
Defined in:
lib/gcloud/datastore/key.rb

Overview

Key

Every Datastore record has an identifying key, which includes the record’s entity kind and a unique identifier. The identifier may be either a key name string, assigned explicitly by the application, or an integer numeric ID, assigned automatically by Datastore.

key = Gcloud::Datastore::Key.new "User", "username"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(kind = nil, id_or_name = nil) ⇒ Key

Returns a new instance of Key.



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# File 'lib/gcloud/datastore/key.rb', line 85

def initialize kind = nil, id_or_name = nil
  @kind = kind
  if id_or_name.is_a? Integer
    @id = id_or_name
  else
    @name = id_or_name
  end
end

Instance Attribute Details

#dataset_id ⇒ Object

The dataset_id of the Key.

Returns

String

Example

require "gcloud"

gcloud = Gcloud.new "my-todo-project",
                    "/path/to/keyfile.json"

dataset = gcloud.datastore
entity = dataset.find "User", "heidi"
entity.key.dataset_id #=> "my-todo-project"



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# File 'lib/gcloud/datastore/key.rb', line 63

def dataset_id
  @dataset_id
end

#id ⇒ Object

The id of the Key.

Returns

Integer or nil

Example

key = Gcloud::Datastore::Key.new "User", 123456
key.id #=> 123456



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# File 'lib/gcloud/datastore/key.rb', line 128

def id
  @id
end

#kind ⇒ Object

The kind of the Key.

Returns

String

Example

key = Gcloud::Datastore::Key.new "User"
key.kind #=> "User"
key.kind = "Task"



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# File 'lib/gcloud/datastore/key.rb', line 43

def kind
  @kind
end

#name ⇒ Object

The name of the Key.

Returns

String or nil

Example

key = Gcloud::Datastore::Key.new "User", "heidi"
key.name #=> "heidi"



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# File 'lib/gcloud/datastore/key.rb', line 164

def name
  @name
end

#namespace ⇒ Object

The namespace of the Key.

Returns

String or nil

Example

require "gcloud"

gcloud = Gcloud.new "my-todo-project",
                    "/path/to/keyfile.json"

dataset = gcloud.datastore
entity = dataset.find "User", "heidi"
entity.key.namespace #=> "ns~todo-project"



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# File 'lib/gcloud/datastore/key.rb', line 83

def namespace
  @namespace
end

#parent ⇒ Object

The parent of the Key.

Returns

Key or nil

Example

require "gcloud"

gcloud = Gcloud.new
dataset = gcloud.datastore

user = dataset.find "User", "heidi"
query = Gcloud::Datastore::Query.new
query.kind("List").
  ancestor(user.key)
lists = dataset.run query
lists.first.key.parent #=> Key("User", "heidi")



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# File 'lib/gcloud/datastore/key.rb', line 205

def parent
  @parent
end

Class Method Details

.from_proto(proto) ⇒ Object

Create a new Key from a protocol buffer object. This is not part of the public API.



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# File 'lib/gcloud/datastore/key.rb', line 262

def self.from_proto proto #:nodoc:
  # Disable rules because the complexity here is neccessary.
  key_proto = proto.dup
  key = Key.new
  proto_path_element = Array(key_proto.path_element).pop
  if proto_path_element
    key = Key.new proto_path_element.kind,
                  proto_path_element.id || proto_path_element.name
  end
  if key_proto.partition_id
    key.dataset_id = key_proto.partition_id.dataset_id
    key.namespace  = key_proto.partition_id.namespace
  end
  if Array(key_proto.path_element).count > 0
    key.parent = Key.from_proto(key_proto)
  end
  # Freeze the key to make it immutable.
  key.freeze
  key
end

Instance Method Details

#complete? ⇒ Boolean

Determine if the key is complete. A complete key has either an id or a name.

Inverse of #incomplete?

Returns:

  • (Boolean) 


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# File 'lib/gcloud/datastore/key.rb', line 232

def complete?
  !incomplete?
end

#incomplete? ⇒ Boolean

Determine if the key is incomplete. An incomplete key has neither an id nor a name.

Inverse of #complete?

Returns:

  • (Boolean) 


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# File 'lib/gcloud/datastore/key.rb', line 241

def incomplete?
  kind.nil? || (id.nil? && (name.nil? || name.empty?))
end

#path ⇒ Object

Represent the Key’s path (including parent) as an array of arrays. Each inner array contains two values, the kind and the id or name. If neither an id or name exist then nil will be returned.

Returns

Array of arrays

Example

key = Gcloud::Datastore::Key.new "List", "todos"
key.parent = Gcloud::Datastore::Key.new "User", "heidi"
key.path #=> [["User", "heidi"], ["List", "todos"]]



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# File 'lib/gcloud/datastore/key.rb', line 222

def path
  new_path = parent ? parent.path : []
  new_path << [kind, (id || name)]
end

#to_proto ⇒ Object

Convert the Key to a protocol buffer object. This is not part of the public API.



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# File 'lib/gcloud/datastore/key.rb', line 248

def to_proto #:nodoc:
  Proto::Key.new.tap do |k|
    k.path_element = path.map do |pe_kind, pe_id_or_name|
      Proto.new_path_element pe_kind, pe_id_or_name
    end
    k.partition_id = Proto.new_partition_id dataset_id, namespace
  end
end