Class: Neo4j::Rails::Relationships::NodesDSL

Inherits:

Object

• Object
• Neo4j::Rails::Relationships::NodesDSL

show all

Includes:

Enumerable

Defined in:

lib/neo4j/rails/relationships/node_dsl.rb

Overview

Constant Summary

CORE_TRAVERSAL_METHODS =

These methods are using the Neo4j::Core::Traversal::Traverser which means that only persisted relationship will be seen but more advanced traversal can be performed.

[:depth, :outgoing, :incoming, :both, :expand, :depth_first, :breadth_first, :eval_paths, :unique, :expander, :prune, :filter, :include_start_node, :rels, :eval_paths, :query]

Instance Method Summary (collapse)

• - (Object) <<(other)

  Adds a new node to the relationship, no transaction is needed.

• - (Object) [](index)

  Returns the n:th item in the relationship.

• - (Object) all(*args)

  Same as #find except that it returns an Enumerator of all nodes found.

• - (Boolean) blank?
• - (Neo4j::Rails::Model) build(attrs = {})

  Creates a new node given the specified attributes and connect it with a relationship.

• - (Object) count (also: #length)

  Counts all relationships.

• - (Neo4j::Rails::Model) create(attrs = {})

  Same as #build except that the relationship and node are saved.

• - (Neo4j::Rails::Model) create!(attrs)

  Same as #create but will raise an exception if an error (like validation) occurs.

• - (Object) delete(*nodes)

  Delete relationships to the given nodes.

• - (Object) delete_all

  Deletes all nodes and relationships, similar to #destroy_all.

• - (Object) destroy_all

  Destroys all nodes (!) and relationship.

• - (Object) each
• - (Boolean) empty?
• - (Neo4j::Rails::Model) find(*args, &block)

  Find one node in the relationship.

• - (Object) first(*args)

  Returns first node in the relationship specified by the arguments or returns nil.

• - (NodesDSL) initialize(storage, dir) constructor

  A new instance of NodesDSL.

• - (Boolean) is_a?(type)
• - (Boolean) persisted?
• - (Boolean) rel_changed?
• - (Object) to_ary
• - (Object) to_s

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 13

def initialize(storage, dir)
  @storage = storage
  @dir = dir
end

node.friends << other

node.friends = ['42', '32']

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 65

def <<(other)
  if other.is_a?(String)
    # this is typically called in an assignment operator, person.friends = ['42', '32']
    node = Neo4j::Node.load(other)
    @storage.create_relationship_to(node, @dir) unless all.include?(node)
  else
    # allow multiple relationships to the same node
    @storage.create_relationship_to(other, @dir)
  end
  self
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 87

def [](index)
  i = 0
  each { |x| return x if i == index; i += 1 }
  nil # out of index
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 143

def all(*args)
  unless args.empty?
    raise "Illegal argument, expected a node" unless args.first.kind_of?(Neo4j::NodeMixin)
    enum = Enumerator.new(@storage, :each_node, @dir).find { |n| n == args.first }
  else
    enum = Enumerator.new(@storage, :each_node, @dir)
  end
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 197

def blank?
  false unless empty?
end

class Person < Neo4j::Rails::Model
   has_n(:friends).to(Person).relationship(Friend)
   has_n(:knows)
end

Person.friends.build(:name => 'kalle')  # creates a Person and Friends class.
Person.knows.build(:name => 'kalle') # creates a Neo4j::Rails::Model and Neo4j::Rails::Relationship class

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 32

def build(attrs = {})
  self << (node = @storage.build(attrs))
  node
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 177

def count
  @storage.count(@dir)
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 40

def create(attrs = {})
  self << (node = @storage.create(attrs))
  node.save
  node
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 49

def create!(attrs)
  self << (node = @storage.create(attrs))
  node.save!
  node
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 189

def delete(*nodes)
  @storage.destroy_rels(@dir, *nodes)
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 172

def delete_all
  each { |n| n.delete }
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 167

def destroy_all
  each { |n| n.destroy }
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 183

def each
  @storage.each_node(@dir) { |n| yield n } # Why passing the &block through doesn't work on JRuby 1.9?
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 193

def empty?
  !@storage.relationships?(@dir)
end

class Actor < Neo4j::Rails::Model
  has_n(:acted_in)
end

actor.acted_in.find(:all)

actor.acted_in.find(:first)

actor.acted_in.find(some_movie)

actor.acted_in.find(some_movie.id)

actor.acted_in.find{|n| n.title == 'movie_1'}

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 123

def find(*args, &block)
  return super(*args, &block) if block

  case args.first
    when :all, :first
      kind = args.shift
      send(kind, *args)
    when "0", 0
      nil
    else
      if ((args.first.is_a?(Integer) || args.first.is_a?(String)) && args.first.to_i > 0)
        find_by_id(*args)
      else
        first(*args)
      end
  end
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 153

def first(*args)
  if result = all(*args)
    if result.respond_to?(:collect) #if it's enumerable, get the first result
      result.first
    else
      result
    end
  else
    nil
  end
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 93

def is_a?(type)
  # ActionView requires this for nested attributes to work
  return true if Array == type
  super
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 77

def persisted?
  @storage.persisted?
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 205

def rel_changed?
  @storage.persisted?
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 81

def to_ary
  all.to_a
end

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# File 'lib/neo4j/rails/relationships/node_dsl.rb', line 201

def to_s
  "Node dir: #{@dir}, #{@storage}"
end