module ClosureTree::HashTreeSupport

Public Instance Methods

build_hash_tree(tree_scope) click to toggle source

Builds nested hash structure using the scope returned from the passed in scope

# File lib/closure_tree/hash_tree_support.rb, line 25
def build_hash_tree(tree_scope)
  tree = ActiveSupport::OrderedHash.new
  id_to_hash = {}

  tree_scope.each do |ea|
    h = id_to_hash[ea.id] = ActiveSupport::OrderedHash.new
    (id_to_hash[ea._ct_parent_id] || tree)[ea] = h
  end
  tree
end
default_tree_scope(scope, limit_depth = nil) click to toggle source
# File lib/closure_tree/hash_tree_support.rb, line 3
    def default_tree_scope(scope, limit_depth = nil)
        # Deepest generation, within limit, for each descendant
        # NOTE: Postgres requires HAVING clauses to always contains aggregate functions (!!)
        having_clause = limit_depth ? "HAVING MAX(generations) <= #{limit_depth - 1}" : ''
        generation_depth = <<-SQL.squish
          INNER JOIN (
            SELECT descendant_id, MAX(generations) as depth
            FROM #{quoted_hierarchy_table_name}
            GROUP BY descendant_id
            #{having_clause}
          ) #{ t_alias_keyword } generation_depth
            ON #{quoted_table_name}.#{model_class.primary_key} = generation_depth.descendant_id
        SQL
        scope_with_order(scope.joins(generation_depth), 'generation_depth.depth')
    end
hash_tree(tree_scope, limit_depth = nil) click to toggle source
# File lib/closure_tree/hash_tree_support.rb, line 19
def hash_tree(tree_scope, limit_depth = nil)
  limited_scope = limit_depth ? tree_scope.where("#{quoted_hierarchy_table_name}.generations <= #{limit_depth - 1}") : tree_scope
  build_hash_tree(limited_scope)
end