Class: Neo4j::Wrapper::HasN::Nodes

Inherits:
Object
  • Object
show all
Includes:
Enumerable, Core::ToJava
Defined in:
lib/neo4j-wrapper/has_n/nodes.rb

Overview

The object created by a has_n or has_one Neo4j::NodeMixin class method which enables creating and traversal of nodes.

See Also:

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node, decl_rel, cypher_query_hash = nil, &cypher_block) ⇒ Nodes

:nodoc:



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 12

def initialize(node, decl_rel, cypher_query_hash = nil, &cypher_block) # :nodoc:
  @node = node
  @decl_rel = decl_rel
  @cypher_block = cypher_block
  @cypher_query_hash = cypher_query_hash
  self.class.define_rule_methods_on(self, decl_rel)
end

Class Method Details

.define_rule_methods_on(instance, decl_rel) ⇒ Object 



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 20

def self.define_rule_methods_on(instance, decl_rel )
  rule_node = Neo4j::Wrapper::Rule::Rule.rule_node_for(decl_rel.target_class)

  singelton = class << instance;
    self;
  end

  rule_node && rule_node.rules.each do |rule|
    next if rule.rule_name == :all
    singelton.send(:define_method, rule.rule_name) do |*cypher_query_hash, &cypher_block|
      raise "Not a hash, can't create a cypher where clause'" if cypher_query_hash.first && !cypher_query_hash.first.is_a?(Hash)
      proc = Proc.new do |m|
        m.incoming(rule.rule_name)
        if cypher_block
          self.instance_exec(m, &cypher_block)
        end
      end
      query(cypher_query_hash.first, &proc)
    end
  end
end

Instance Method Details

#<<(other) ⇒ Object

Creates a relationship between this and the other node.

Examples:

Person includes the Neo4j::NodeMixin and declares a has_n :friends


p = Person.new # Node has declared having a friend type of relationship
n1 = Node.new
n2 = Node.new

p.friends << n2 << n3

Returns:

  • self



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 113

def <<(other)
  @decl_rel.create_relationship_to(@node, other)
  self
end

#[](index) ⇒ Neo4j::NodeMixin, ...

Traverse the relationship till the index position

Returns:



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 57

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

#_each ⇒ Object

returns none wrapped nodes, you may get better performance using this method



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 80

def _each
  @decl_rel._each_node(@node) { |n| yield n }
end

#each ⇒ Object

Required by the Enumerable mixin.



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 71

def each
  if @cypher_block || @cypher_query_hash
    query(@cypher_query_hash, &@cypher_block).each { |i| yield i }
  else
    @decl_rel.each_node(@node) { |n| yield n } # Should use yield here as passing &block through doesn't always work (why?)
  end
end

#empty? ⇒ Boolean

Returns true if there are no node in this type of relationship

Returns:

  • (Boolean) 


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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 90

def empty?
  first == nil
end

#is_a?(type) ⇒ Boolean

Pretend we are an array - this is necessarily for Rails actionpack/actionview/formhelper to work with this

Returns:

  • (Boolean) 


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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 64

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

#new(other) ⇒ Object

Creates a relationship instance between this and the other node. Returns the relationship object



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 97

def new(other)
  @decl_rel.create_relationship_to(@node, other)
end

#query(cypher_query_hash = nil, &block) ⇒ Object 



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 51

def query(cypher_query_hash = nil, &block)
  Neo4j::Core::Traversal::CypherQuery.new(@node.neo_id, @decl_rel.dir, [@decl_rel.rel_type], cypher_query_hash, &block)
end

#to_ary ⇒ Object

Returns an real ruby array.



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 85

def to_ary
  self.to_a
end

#to_s ⇒ Object 



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# File 'lib/neo4j-wrapper/has_n/nodes.rb', line 43

def to_s
  if @cypher_block || @cypher_query_hash
    query(@cypher_query_hash, &@cypher_block).to_s
  else
    "HasN::Nodes [#{@decl_rel.dir}, id: #{@node.neo_id} type: #{@decl_rel && @decl_rel.rel_type} decl_rel:#{@decl_rel}]"
  end
end