aboutsummaryrefslogtreecommitdiffstats
path: root/activerecord/lib/active_record/relation/spawn_methods.rb
blob: 1d2151fdb26bd28fa758db3c3cacf07f71b54acd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/hash/slice'
require 'active_record/relation/merger'

module ActiveRecord
  module SpawnMethods
    
    # Merges in the conditions from <tt>other</tt>, if <tt>other</tt> is an <tt>ActiveRecord::Relation</tt>.
    # Returns an array representing the union of the resulting records with <tt>other</tt>, if <tt>other</tt> is an array.
    #
    # ==== Examples
    #
    #   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 union 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!)
    #
    def merge(other)
      if other.is_a?(Array)
        to_a & other
      elsif other
        clone.merge!(other)
      else
        self
      end
    end

    def merge!(other)
      if other.is_a?(Hash)
        Relation::HashMerger.new(self, other).merge
      else
        Relation::Merger.new(self, other).merge
      end
    end

    # Removes from the query the condition(s) specified in +skips+.
    #
    # Example:
    #
    #   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
    #
    def except(*skips)
      result = self.class.new(@klass, table, values.except(*skips))
      result.default_scoped = default_scoped
      result.extend(*extending_values) if extending_values.any?
      result
    end

    # Removes any condition from the query other than the one(s) specified in +onlies+.
    #
    # Example:
    #
    #   Post.order('id asc').only(:where)         # discards the order condition
    #   Post.order('id asc').only(:where, :order) # uses the specified order
    #
    def only(*onlies)
      result = self.class.new(@klass, table, values.slice(*onlies))
      result.default_scoped = default_scoped
      result.extend(*extending_values) if extending_values.any?
      result
    end

  end
end