Class: Squeel::Nodes::Join

Inherits:
Object
  • Object
show all
Defined in:
lib/squeel/nodes/join.rb

Overview

A node representing a joined association

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, type = Arel::InnerJoin, klass = nil) ⇒ Join

Create a new Join node

Parameters:

  • name (Symbol) —

    The association name

  • type (Arel::InnerJoin, Arel::OuterJoin) (defaults to: Arel::InnerJoin) —

    The ARel join class

  • klass (Class, String, Symbol) (defaults to: nil) —

    The polymorphic belongs_to class or class name



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# File 'lib/squeel/nodes/join.rb', line 21

def initialize(name, type = Arel::InnerJoin, klass = nil)
  @_name, @_type = name, type
  @_klass = convert_to_class(klass) if klass
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#node_name ⇒ KeyPath #node_name(klass) ⇒ KeyPath

Ensures that a Join can be used as the base of a new KeyPath

Overloads:

  • #node_name ⇒ KeyPath

    Creates a new KeyPath with this Join as the base and the method_name as the endpoint

    Returns:

  • #node_name(klass) ⇒ KeyPath

    Creates a new KeyPath with this Join as the base and a polymorphic belongs_to join as the endpoint

    Parameters:

    • klass (Class) —

      The polymorphic class for the join

    Returns:



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# File 'lib/squeel/nodes/join.rb', line 70

def method_missing(method_id, *args)
  super if method_id == :to_ary
  if (args.size == 1) && (Class === args[0])
    KeyPath.new(self, Join.new(method_id, Arel::InnerJoin, args[0]))
  else
    KeyPath.new(self, method_id)
  end
end

Instance Attribute Details

#_klass ⇒ Class, NilClass

Returns:

  • (Class) —

    The polymorphic belongs_to join class

  • (NilClass) —

    If the join is not a polymorphic belongs_to join



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# File 'lib/squeel/nodes/join.rb', line 15

def _klass
  @_klass
end

#_name ⇒ Symbol (readonly)

Returns The join’s association name.

Returns:

  • (Symbol) —

    The join’s association name



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# File 'lib/squeel/nodes/join.rb', line 8

def _name
  @_name
end

#_type ⇒ Arel::InnerJoin, Arel::OuterJoin (readonly)

Returns The ARel join type.

Returns:

  • (Arel::InnerJoin, Arel::OuterJoin) —

    The ARel join type



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# File 'lib/squeel/nodes/join.rb', line 11

def _type
  @_type
end

Instance Method Details

#convert_to_class(value) ⇒ Class (private)

Convert the given value into a class.

Parameters:

  • value (Class, String, Symbol) —

    The value to be converted

Returns:

  • (Class) —

    The class after conversion



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# File 'lib/squeel/nodes/join.rb', line 100

def convert_to_class(value)
  case value
  when String, Symbol
    Kernel.const_get(value)
  when Class
    value
  else
    raise ArgumentError, "#{value} cannot be converted to a Class"
  end
end

#eql?(other) ⇒ Boolean Also known as: ==

Compare with other objects

Returns:

  • (Boolean) 


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# File 'lib/squeel/nodes/join.rb', line 54

def eql?(other)
  self.class == other.class &&
  self._name  == other._name &&
  self._type == other._type &&
  self._klass == other._klass
end

#inner ⇒ Join

Set the join type to an inner join

Returns:

  • (Join) —

    The join, with an updated join type.



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# File 'lib/squeel/nodes/join.rb', line 28

def inner
  @_type = Arel::InnerJoin
  self
end

#outer ⇒ Join

Set the join type to an outer join

Returns:

  • (Join) —

    The join, with an updated join type.



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# File 'lib/squeel/nodes/join.rb', line 35

def outer
  @_type = Arel::OuterJoin
  self
end

#polymorphic? ⇒ NilClass, Class

Returns a true value (the class itself) if a polymorphic belongs_to class has been set

Returns:

  • (NilClass, Class) —

    The class, if present.



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# File 'lib/squeel/nodes/join.rb', line 49

def polymorphic?
  @_klass
end

#to_sym ⇒ NilClass

expand_hash_conditions_for_aggregates assumes our hash keys can be converted to symbols, so this has to be implemented, but it doesn’t really have to do anything useful.

Returns:

  • (NilClass) —

    Just to avoid bombing out on expand_hash_conditions_for_aggregates



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# File 'lib/squeel/nodes/join.rb', line 91

def to_sym
  nil
end

#~ ⇒ KeyPath

Return a KeyPath containing only this Join, but flagged as absolute. This helps Joins behave more like a KeyPath, as anyone using the Squeel DSL is likely to think of them as such.

Returns:

  • (KeyPath) —

    An absolute KeyPath, containing only this Join



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# File 'lib/squeel/nodes/join.rb', line 83

def ~
  KeyPath.new [], self, true
end