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

Inherits:
Context
  • Object
show all
Defined in:
lib/ransack/adapters/active_record/context.rb,
lib/ransack/adapters/active_record/3.0/context.rb,
lib/ransack/adapters/active_record/3.1/context.rb,
lib/ransack/adapters/active_record/3.2/context.rb

Constant Summary collapse

JoinDependency = 
::ActiveRecord::Associations::ClassMethods::JoinDependency

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, #chain_scope, #contextualize, for, for_class, for_object, #ransackable_alias, #ransackable_association?, #ransackable_attribute?, #ransackable_scope?, #scope_arity, #searchable_associations, #searchable_attributes, #sortable_attributes, #traverse, #unpolymorphize_association

Constructor Details

#initialize(object, options = {}) ⇒ Context

Redefine a few things for ActiveRecord 3.2.



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# File 'lib/ransack/adapters/active_record/3.0/context.rb', line 18

def initialize(object, options = {})
  super
  @arel_visitor = @engine.connection.visitor
end

Instance Method Details

#alias_tracker ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/ransack/adapters/active_record/context.rb', line 137

def alias_tracker
  @join_dependency.alias_tracker
end

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

Returns:

  • (Boolean) 


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# File 'lib/ransack/adapters/active_record/context.rb', line 44

def attribute_method?(str, klass = @klass)
  exists = false
  if ransackable_attribute?(str, klass)
    exists = true
  elsif (segments = str.split(/_/)).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.



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# File 'lib/ransack/adapters/active_record/context.rb', line 181

def build_correlated_subquery(association)
  join_constraints = extract_joins(association)
  join_root = join_constraints.shift
  join_table = join_root.left
  correlated_key = join_root.right.expr.left
  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 



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# File 'lib/ransack/adapters/active_record/context.rb', line 35

def evaluate(search, opts = {})
  viz = Visitor.new
  relation = @object.where(viz.accept(search.base))
  if search.sorts.any?
    relation = relation.except(:order).reorder(viz.accept(search.sorts))
  end
  opts[:distinct] ? relation.distinct : relation
end

#join_associations ⇒ Object

All dependent JoinAssociation items used in the search query



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# File 'lib/ransack/adapters/active_record/context.rb', line 122

def join_associations
  raise NotImplementedError,
  "ActiveRecord 4.1 and later does not use join_associations. Use join_sources."
end

#join_sources ⇒ Object

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.



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# File 'lib/ransack/adapters/active_record/context.rb', line 97

def join_sources
  base, joins =
  if ::ActiveRecord::VERSION::MAJOR >= 5
    [
      Arel::SelectManager.new(@object.table),
      @join_dependency.join_constraints(@object.joins_values, @join_type)
    ]
  else
    [
      Arel::SelectManager.new(@object.engine, @object.table),
      @join_dependency.join_constraints(@object.joins_values)
    ]
  end
  joins.each do |aliased_join|
    base.from(aliased_join)
  end
  base.join_sources
end

#klassify(obj) ⇒ Object 



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# File 'lib/ransack/adapters/active_record/context.rb', line 71

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 



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# File 'lib/ransack/adapters/active_record/context.rb', line 141

def lock_association(association)
  @lock_associations << association
end

#primary_key ⇒ Object 



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# File 'lib/ransack/adapters/active_record/context.rb', line 195

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

#relation_for(object) ⇒ Object 



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# File 'lib/ransack/adapters/active_record/context.rb', line 20

def relation_for(object)
  object.all
end

#remove_association(association) ⇒ Object 



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# File 'lib/ransack/adapters/active_record/context.rb', line 146

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

#table_for(parent) ⇒ Object 



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# File 'lib/ransack/adapters/active_record/context.rb', line 67

def table_for(parent)
  parent.table
end

#type_for(attr) ⇒ Object 



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

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 = @engine.connection.schema_cache
  unless schema_cache.send(database_table_exists?, table)
    raise "No table named #{table} exists."
  end
  schema_cache.columns_hash(table)[name].type
end