Module: ActiveRecord::SpawnMethods

Included in:
Relation
Defined in:
lib/active_record/relation/spawn_methods.rb

Instance Method Summary collapse

Instance Method Details

#except(*skips) ⇒ Object

Removes from the query the condition(s) specified in skips.

Post.order('id asc').except(:order)                  # discards the order condition
Post.where('id > 10').order('id asc').except(:where) # discards the where condition but keeps the order



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# File 'lib/active_record/relation/spawn_methods.rb', line 58

def except(*skips)
  relation_with values.except(*skips)
end

#merge(other, *rest) ⇒ Object

Merges in the conditions from other, if other is an ActiveRecord::Relation. Returns an array representing the intersection of the resulting records with other, if other is an array.

Post.where(published: true).joins(:comments).merge( Comment.where(spam: false) )
# Performs a single join query with both where conditions.

recent_posts = Post.order('created_at DESC').first(5)
Post.where(published: true).merge(recent_posts)
# Returns the intersection of all published posts with the 5 most recently created posts.
# (This is just an example. You'd probably want to do this with a single query!)

Procs will be evaluated by merge:

Post.where(published: true).merge(-> { joins(:comments) })
# => Post.where(published: true).joins(:comments)

This is mainly intended for sharing common conditions between multiple associations.



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# File 'lib/active_record/relation/spawn_methods.rb', line 31

def merge(other, *rest)
  if other.is_a?(Array)
    records & other
  elsif other
    spawn.merge!(other, *rest)
  else
    raise ArgumentError, "invalid argument: #{other.inspect}."
  end
end

#merge!(other, *rest) ⇒ Object

:nodoc:



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# File 'lib/active_record/relation/spawn_methods.rb', line 41

def merge!(other, *rest) # :nodoc:
  options = rest.extract_options!
  if other.is_a?(Hash)
    Relation::HashMerger.new(self, other, options[:rewhere]).merge
  elsif other.is_a?(Relation)
    Relation::Merger.new(self, other, options[:rewhere]).merge
  elsif other.respond_to?(:to_proc)
    instance_exec(&other)
  else
    raise ArgumentError, "#{other.inspect} is not an ActiveRecord::Relation"
  end
end

#only(*onlies) ⇒ Object

Removes any condition from the query other than the one(s) specified in onlies.

Post.order('id asc').only(:where)         # discards the order condition
Post.order('id asc').only(:where, :order) # uses the specified order



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# File 'lib/active_record/relation/spawn_methods.rb', line 66

def only(*onlies)
  relation_with values.slice(*onlies)
end

#spawn ⇒ Object

This is overridden by Associations::CollectionProxy



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# File 'lib/active_record/relation/spawn_methods.rb', line 10

def spawn #:nodoc:
  already_in_scope? ? klass.all : clone
end