Class: Google::Cloud::Datastore::Key

Inherits:
Object
  • Object
show all
Defined in:
lib/google/cloud/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.

Examples:

task_key = Google::Cloud::Datastore::Key.new "Task", "sampleTask"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(kind = nil, id_or_name = nil) ⇒ Google::Cloud::Datastore::Dataset::Key

Create a new Key instance.

Examples:

task_key = Google::Cloud::Datastore::Key.new "Task", "sampleTask"

Parameters:

  • kind (String) (defaults to: nil) —

    The kind of the Key. This is optional.

  • id_or_name (Integer, String) (defaults to: nil) —

    The id or name of the Key. This is optional.



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# File 'lib/google/cloud/datastore/key.rb', line 93

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

#id ⇒ Integer?

The id of the Key.

Examples:

task_key = Google::Cloud::Datastore::Key.new "Task", 123456
task_key.id #=> 123456

Returns:

  • (Integer, nil) 


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# File 'lib/google/cloud/datastore/key.rb', line 130

def id
  @id
end

#kind ⇒ String

The kind of the Key.

Examples:

key = Google::Cloud::Datastore::Key.new "TaskList"
key.kind #=> "TaskList"
key.kind = "Task"

Returns:

  • (String) 


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# File 'lib/google/cloud/datastore/key.rb', line 41

def kind
  @kind
end

#name ⇒ String?

The name of the Key.

Examples:

task_key = Google::Cloud::Datastore::Key.new "Task", "sampleTask"
task_key.name #=> "sampleTask"

Returns:

  • (String, nil) 


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# File 'lib/google/cloud/datastore/key.rb', line 160

def name
  @name
end

#namespace ⇒ String?

The namespace of the Key.

Examples:

require "google/cloud/datastore"

datastore = Google::Cloud::Datastore.new(
  project: "my-todo-project",
  keyfile: "/path/to/keyfile.json"
)

task = datastore.find "Task", "sampleTask"
task.key.namespace #=> "ns~todo-project"

Returns:

  • (String, nil) 


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# File 'lib/google/cloud/datastore/key.rb', line 79

def namespace
  @namespace
end

#parent ⇒ Key?

The parent of the Key.

Examples:

require "google/cloud/datastore"

datastore = Google::Cloud::Datastore.new

task_list = datastore.find "TaskList", "default"
query = datastore.query("Task").
  ancestor(task_list)
lists = datastore.run query
lists.first.key.parent #=> Key("TaskList", "default")

Returns:



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# File 'lib/google/cloud/datastore/key.rb', line 201

def parent
  @parent
end

#project ⇒ String Also known as: dataset_id

The project of the Key.

Examples:

require "google/cloud/datastore"

datastore = Google::Cloud::Datastore.new(
  project: "my-todo-project",
  keyfile: "/path/to/keyfile.json"
)

task = datastore.find "Task", "sampleTask"
task.key.project #=> "my-todo-project"

Returns:

  • (String) 


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# File 'lib/google/cloud/datastore/key.rb', line 59

def project
  @project
end

Class Method Details

.from_grpc(grpc) ⇒ Object

object.



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# File 'lib/google/cloud/datastore/key.rb', line 268

def self.from_grpc grpc
  return nil if grpc.nil?
  key_grpc = grpc.dup
  key = Key.new
  path_grpc = key_grpc.path.pop
  if path_grpc
    id_or_name =
      (path_grpc.id_type == :id ? path_grpc.id : path_grpc.name)
    key = Key.new path_grpc.kind, id_or_name
  end
  if key_grpc.partition_id
    key.project = key_grpc.partition_id.project_id
    key.namespace = key_grpc.partition_id.namespace_id
  end
  key.parent = Key.from_grpc(key_grpc) if key_grpc.path.count > 0
  # 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/google/cloud/datastore/key.rb', line 226

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/google/cloud/datastore/key.rb', line 235

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

#path ⇒ Array<Array<(String, String)>>

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.

Examples:

parent_key = Google::Cloud::Datastore::Key.new "TaskList", "default"
task_key = Google::Cloud::Datastore::Key.new "Task", "sampleTask"
task_key.parent = parent_key
task_key.path #=> [["TaskList", "default"], ["Task", "sampleTask"]]

Returns:

  • (Array<Array<(String, String)>>) 


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# File 'lib/google/cloud/datastore/key.rb', line 216

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

#serialized_size ⇒ Object

The number of bytes the Key will take to serialize during API calls.



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

def serialized_size
  to_grpc.to_proto.length
end

#to_grpc ⇒ Object 



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# File 'lib/google/cloud/datastore/key.rb', line 247

def to_grpc
  grpc_path = path.map do |pe_kind, pe_id_or_name|
    path_args = { kind: pe_kind }
    if pe_id_or_name.is_a? Integer
      path_args[:id] = pe_id_or_name
    elsif pe_id_or_name.is_a? String
      path_args[:name] = pe_id_or_name unless pe_id_or_name.empty?
    end
    Google::Datastore::V1::Key::PathElement.new(path_args)
  end
  grpc = Google::Datastore::V1::Key.new(path: grpc_path)
  if project || namespace
    grpc.partition_id = Google::Datastore::V1::PartitionId.new(
      project_id: project.to_s, namespace_id: namespace.to_s)
  end
  grpc
end