Method: Zena::Use::QueryNode::Compiler#resolve_scope_idx_fields

Defined in:

lib/zena/use/query_node.rb

#resolve_scope_idx_fields(arg1, arg2) ⇒ Object

# File 'lib/zena/use/query_node.rb', line 347

def resolve_scope_idx_fields(arg1, arg2)
  if arg1.first == :function
    # contact.log_at.year
    # arg1 = [:function, [:field, "tag"], [:method, "created_at"]]
    # arg2 = [:method, "year"]
    class_name = arg1[1][1]
    field_name = arg1[2][1]
    function  = arg2
  elsif arg1[0] == :field && arg2[0] == :method
    # contact.log_at  or  log_at.year
    # arg1 = [:field, "contact"]
    class_name = arg1[1]
    # arg2 = [:method, "name"]
    field_name = arg2[1]
    function   = nil
  else
    return [arg1, arg2]
  end

  scope_idx_field = "#{class_name}_#{field_name}"
  if fld = get_scope_index_field(scope_idx_field)
    return [[:idx_field, fld], function]
  else
    # 2. Try to use relation as scope filter 'hot.title = "xxx"', 'hot.title = "xxx"'
    # Multiple links with hot.id = 334 and hot2.id = 323...
    rel = class_name.sub(/\d$/,'')

    source_kpath = @query.main_class.kpath

    if rel = RelationProxy.find_by_role(rel.singularize, source_kpath)
      table_to_use = add_key_value_table('jnode', 'nodes', class_name) do |tbl_name|
        # This block is only executed once per relation name (once for 'hot', once for 'hot2')
        # TODO: Can we remove this ?
        distinct!
        lnk = add_key_value_table('links', 'links', class_name) do |lt|
          "#{lt}.#{rel.link_side} = #{table(main_table)}.id AND #{lt}.relation_id = #{rel.id}"
        end
        
        %Q{#{tbl_name}.id = #{lnk}.#{rel.other_side}}
      end
      
      # Temporarily move to the remote class
      tbl_alias_bak = context[:table_alias]
      context[:table_alias] = table_to_use
      main_class_bak = @query.main_class
      
        @query.main_class = rel.other_vclass
        fld = process_field(field_name)
        
      # Move back
      @query.main_class = main_class_bak
      context[:table_alias] = tbl_alias_bak
      if fld
        [[:idx_field, fld], function]
      else
        nil
      end
    else
      # not a scope index field
      return [arg1, arg2]
    end
  end
end