module ClosureTree::Finders::ClassMethods
Public Instance Methods
find_all_by_generation(generation_level)
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# File lib/closure_tree/finders.rb, line 115 def find_all_by_generation(generation_level) s = joins(<<-SQL.squish) INNER JOIN ( SELECT #{primary_key} as root_id FROM #{_ct.quoted_table_name} WHERE #{_ct.quoted_parent_column_name} IS NULL ) #{ _ct.t_alias_keyword } roots ON (1 = 1) INNER JOIN ( SELECT ancestor_id, descendant_id FROM #{_ct.quoted_hierarchy_table_name} GROUP BY ancestor_id, descendant_id HAVING MAX(generations) = #{generation_level.to_i} ) #{ _ct.t_alias_keyword } descendants ON ( #{_ct.quoted_table_name}.#{primary_key} = descendants.descendant_id AND roots.root_id = descendants.ancestor_id ) SQL _ct.scope_with_order(s) end
find_by_path(path, attributes = {}, parent_id = nil)
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Find the node whose ancestry_path
is path
# File lib/closure_tree/finders.rb, line 136 def find_by_path(path, attributes = {}, parent_id = nil) return nil if path.blank? path = _ct.build_ancestry_attr_path(path, attributes) if path.size > _ct.max_join_tables return _ct.find_by_large_path(path, attributes, parent_id) end scope = where(path.pop) last_joined_table = _ct.table_name path.reverse.each_with_index do |ea, idx| next_joined_table = "p#{idx}" scope = scope.joins(<<-SQL.squish) INNER JOIN #{_ct.quoted_table_name} #{ _ct.t_alias_keyword } #{next_joined_table} ON #{next_joined_table}.#{_ct.quoted_id_column_name} = #{connection.quote_table_name(last_joined_table)}.#{_ct.quoted_parent_column_name} SQL scope = _ct.scoped_attributes(scope, ea, next_joined_table) last_joined_table = next_joined_table end scope.where("#{last_joined_table}.#{_ct.parent_column_name}" => parent_id).readonly(false).first end
find_or_create_by_path(path, attributes = {})
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Find or create nodes such that the ancestry_path
is path
# File lib/closure_tree/finders.rb, line 158 def find_or_create_by_path(path, attributes = {}) attr_path = _ct.build_ancestry_attr_path(path, attributes) find_by_path(attr_path) || begin root_attrs = attr_path.shift _ct.with_advisory_lock do # shenanigans because find_or_create can't infer that we want the same class as this: # Note that roots will already be constrained to this subclass (in the case of polymorphism): root = roots.where(root_attrs).first || _ct.create!(self, root_attrs) root.find_or_create_by_path(attr_path) end end end
leaves()
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# File lib/closure_tree/finders.rb, line 72 def leaves s = joins(<<-SQL.squish) INNER JOIN ( SELECT ancestor_id FROM #{_ct.quoted_hierarchy_table_name} GROUP BY ancestor_id HAVING MAX(#{_ct.quoted_hierarchy_table_name}.generations) = 0 ) #{ _ct.t_alias_keyword } leaves ON (#{_ct.quoted_table_name}.#{primary_key} = leaves.ancestor_id) SQL _ct.scope_with_order(s.readonly(false)) end
lowest_common_ancestor(*descendants)
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# File lib/closure_tree/finders.rb, line 102 def lowest_common_ancestor(*descendants) descendants = descendants.first if descendants.length == 1 && descendants.first.respond_to?(:each) ancestor_id = hierarchy_class .where(descendant_id: descendants) .group(:ancestor_id) .having("COUNT(ancestor_id) = #{descendants.count}") .order(Arel.sql('MIN(generations) ASC')) .limit(1) .pluck(:ancestor_id).first find_by(primary_key => ancestor_id) if ancestor_id end
root()
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Returns an arbitrary node that has no parents.
# File lib/closure_tree/finders.rb, line 68 def root roots.first end
roots()
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# File lib/closure_tree/finders.rb, line 63 def roots _ct.scope_with_order(where(_ct.parent_column_name => nil)) end
with_ancestor(*ancestors)
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# File lib/closure_tree/finders.rb, line 84 def with_ancestor(*ancestors) ancestor_ids = ancestors.map { |ea| ea.is_a?(ActiveRecord::Base) ? ea._ct_id : ea } scope = ancestor_ids.blank? ? all : joins(:ancestor_hierarchies). where("#{_ct.hierarchy_table_name}.ancestor_id" => ancestor_ids). where("#{_ct.hierarchy_table_name}.generations > 0"). readonly(false) _ct.scope_with_order(scope) end
with_descendant(*descendants)
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# File lib/closure_tree/finders.rb, line 93 def with_descendant(*descendants) descendant_ids = descendants.map { |ea| ea.is_a?(ActiveRecord::Base) ? ea._ct_id : ea } scope = descendant_ids.blank? ? all : joins(:descendant_hierarchies). where("#{_ct.hierarchy_table_name}.descendant_id" => descendant_ids). where("#{_ct.hierarchy_table_name}.generations > 0"). readonly(false) _ct.scope_with_order(scope) end
without_instance(instance)
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# File lib/closure_tree/finders.rb, line 55 def without_instance(instance) if instance.new_record? all else where(["#{_ct.quoted_table_name}.#{_ct.quoted_id_column_name} != ?", instance.id]) end end