Class: Ransack::Adapters::ActiveRecord::Context

Inherits:
Context
  • Object
show all
Defined in:
lib/ransack/adapters/active_record/context.rb

Instance Attribute Summary

Attributes inherited from Context

#arel_visitor, #auth_object, #base, #engine, #klass, #object, #search, #search_key

Instance Method Summary collapse

Methods inherited from Context

#association_path, #bind, #bind_pair_for, #chain_scope, #contextualize, for, for_class, for_object, #initialize, #ransackable_alias, #ransackable_association?, #ransackable_attribute?, #ransackable_scope?, #ransackable_scope_skip_sanitize_args?, #scope_arity, #searchable_associations, #searchable_attributes, #sortable_attributes, #traverse, #unpolymorphize_association

Constructor Details

This class inherits a constructor from Ransack::Context

Instance Method Details

#alias_trackerObject


119
120
121
# File 'lib/ransack/adapters/active_record/context.rb', line 119

def alias_tracker
  @join_dependency.send(:alias_tracker)
end

#attribute_method?(str, klass = @klass) ⇒ Boolean

Returns:

  • (Boolean)

53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
# File 'lib/ransack/adapters/active_record/context.rb', line 53

def attribute_method?(str, klass = @klass)
  exists = false
  if ransackable_attribute?(str, klass)
    exists = true
  elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
    remainder = []
    found_assoc = nil
    while !found_assoc && remainder.unshift(segments.pop) &&
    segments.size > 0 do
      assoc, poly_class = unpolymorphize_association(
        segments.join(Constants::UNDERSCORE)
        )
      if found_assoc = get_association(assoc, klass)
        exists = attribute_method?(
          remainder.join(Constants::UNDERSCORE),
          poly_class || found_assoc.klass
          )
      end
    end
  end
  exists
end

#build_correlated_subquery(association) ⇒ Object

Build an Arel subquery that selects keys for the top query, drawn from the first join association's foreign_key.

Example: for an Article that has_and_belongs_to_many Tags

context = Article.search.context
attribute = Attribute.new(context, "tags_name").tap do |a|
  context.bind(a, a.name)
end
context.build_correlated_subquery(attribute.parent).to_sql

# SELECT "articles_tags"."article_id" FROM "articles_tags"
# INNER JOIN "tags" ON "tags"."id" = "articles_tags"."tag_id"
# WHERE "articles_tags"."article_id" = "articles"."id"

The WHERE condition on this query makes it invalid by itself, because it is correlated to the primary key on the outer query.


155
156
157
158
159
160
161
162
163
164
165
166
# File 'lib/ransack/adapters/active_record/context.rb', line 155

def build_correlated_subquery(association)
  join_constraints = extract_joins(association)
  join_root = join_constraints.shift
  correlated_key = extract_correlated_key(join_root)
  subquery = Arel::SelectManager.new(association.base_klass)
  subquery.from(join_root.left)
  subquery.project(correlated_key)
  join_constraints.each do |j|
    subquery.join_sources << Arel::Nodes::InnerJoin.new(j.left, j.right)
  end
  subquery.where(correlated_key.eq(primary_key))
end

#evaluate(search, opts = {}) ⇒ Object


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
# File 'lib/ransack/adapters/active_record/context.rb', line 24

def evaluate(search, opts = {})
  viz = Visitor.new
  relation = @object.where(viz.accept(search.base))

  if search.sorts.any?
    relation = relation.except(:order)
    # Rather than applying all of the search's sorts in one fell swoop,
    # as the original implementation does, we apply one at a time.
    #
    # If the sort (returned by the Visitor above) is a symbol, we know
    # that it represents a scope on the model and we can apply that
    # scope.
    #
    # Otherwise, we fall back to the applying the sort with the "order"
    # method as the original implementation did. Actually the original
    # implementation used "reorder," which was overkill since we already
    # have a clean slate after "relation.except(:order)" above.
    viz.accept(search.sorts).each do |scope_or_sort|
      if scope_or_sort.is_a?(Symbol)
        relation = relation.send(scope_or_sort)
      else
        relation = relation.order(scope_or_sort)
      end
    end
  end

  opts[:distinct] ? relation.distinct : relation
end

#join_sourcesObject

All dependent Arel::Join nodes used in the search query.

This could otherwise be done as `@object.arel.join_sources`, except that ActiveRecord's build_joins sets up its own JoinDependency. This extracts what we need to access the joins using our existing JoinDependency to track table aliases.


99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
# File 'lib/ransack/adapters/active_record/context.rb', line 99

def join_sources
  base, joins = begin
    alias_tracker = ::ActiveRecord::Associations::AliasTracker.create(self.klass.connection, @object.table.name, [])
    constraints   = if ::Gem::Version.new(::ActiveRecord::VERSION::STRING) >= ::Gem::Version.new(Constants::RAILS_6_0)
      @join_dependency.join_constraints(@object.joins_values, alias_tracker)
    else
      @join_dependency.join_constraints(@object.joins_values, @join_type, alias_tracker)
    end

    [
      Arel::SelectManager.new(@object.table),
      constraints
    ]
  end
  joins.each do |aliased_join|
    base.from(aliased_join)
  end
  base.join_sources
end

#klassify(obj) ⇒ Object


80
81
82
83
84
85
86
87
88
89
90
# File 'lib/ransack/adapters/active_record/context.rb', line 80

def klassify(obj)
  if Class === obj && ::ActiveRecord::Base > obj
    obj
  elsif obj.respond_to? :klass
    obj.klass
  elsif obj.respond_to? :base_klass
    obj.base_klass
  else
    raise ArgumentError, "Don't know how to klassify #{obj}"
  end
end

#lock_association(association) ⇒ Object


123
124
125
# File 'lib/ransack/adapters/active_record/context.rb', line 123

def lock_association(association)
  @lock_associations << association
end

#primary_keyObject


168
169
170
# File 'lib/ransack/adapters/active_record/context.rb', line 168

def primary_key
  @object.table[@object.primary_key]
end

#relation_for(object) ⇒ Object


9
10
11
# File 'lib/ransack/adapters/active_record/context.rb', line 9

def relation_for(object)
  object.all
end

#remove_association(association) ⇒ Object


127
128
129
130
131
132
133
134
135
# File 'lib/ransack/adapters/active_record/context.rb', line 127

def remove_association(association)
  return if @lock_associations.include?(association)
  @join_dependency.instance_variable_get(:@join_root).children.delete_if { |stashed|
    stashed.eql?(association)
  }
  @object.joins_values.delete_if { |jd|
    jd.instance_variable_get(:@join_root).children.map(&:object_id) == [association.object_id]
  }
end

#table_for(parent) ⇒ Object


76
77
78
# File 'lib/ransack/adapters/active_record/context.rb', line 76

def table_for(parent)
  parent.table
end

#type_for(attr) ⇒ Object


13
14
15
16
17
18
19
20
21
22
# File 'lib/ransack/adapters/active_record/context.rb', line 13

def type_for(attr)
  return nil unless attr && attr.valid?
  name         = attr.arel_attribute.name.to_s
  table        = attr.arel_attribute.relation.table_name
  schema_cache = self.klass.connection.schema_cache
  unless schema_cache.send(:data_source_exists?, table)
    raise "No table named #{table} exists."
  end
  attr.klass.columns.find { |column| column.name == name }.type
end