Method: ThroughHierarchy::Hierarchicals::Hierarchical#join_best_rank

Defined in:
lib/through_hierarchy/hierarchicals/hierarchical.rb

#join_best_rank(group_by: nil) ⇒ Object

Join @model to @source only on best hierarchy matches FASTER METHOD: join source to source alias on source.rank < alias.rank where alias does not exist This performs OK. TODO: return arel once we know how to use the binds properly



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# File 'lib/through_hierarchy/hierarchicals/hierarchical.rb', line 97

def join_best_rank(group_by: nil)
  better_rank = spawn(@source.alias("better_hierarchy"))
  join_condition_array = [
    better_rank.filters,
    better_rank.hierarchy_rank.lt(hierarchy_rank)
  ]
  join_condition_array << better_rank.source[group_by].eq(@source[group_by]) if group_by.present?
  arel = @model.arel_table.
    join(@source).on(filters).
    join(better_rank.source, Arel::Nodes::OuterJoin).
    on(and_conditions(join_condition_array)).
    where(better_rank.source[:id].eq(nil))
  result = @model.joins(@hierarchy).joins(arel.join_sources).order(arel.orders)
    arel.constraints.each{|cc| result = result.where(cc)}
    return result
end