Method: Zena::Use::QueryNode::Compiler#process_field

Defined in:

lib/zena/use/query_node.rb

#process_field(field_name) ⇒ Object

Overwrite this and take care to check for valid fields.

# File 'lib/zena/use/query_node.rb', line 204

def process_field(field_name)
  if fld = @query.attributes_alias[field_name]
    # use custom query alias value defined in select clause: 'custom_a AS validation'
    if processing_filter?
      # We need to use the full original clause, except when the clause contains group functions (MAX, MIN, etc).
      # If the clause is too complex, we need to use something simpler or it will break (custom queries).
      "(#{fld})"
    else
      fld
    end
  elsif processing_filter? && map_def = self.class.filter_fields[field_name]
    # Special filter fields such as 'role', 'tag' or 'class'
    if map_def.kind_of?(String)
      return map_def
    elsif table_def = map_def[:table]
      use_name, source, target, filter = table_def
      table_to_use = add_key_value_table(use_name, target, map_def[:key]) do |tbl_name|
        # This block is only executed once
        filter.gsub(
          'TABLE1', table(source)
        ).gsub(
          'TABLE2', tbl_name
        )
      end
    else
      table_to_use = table
    end
    "#{table_to_use}.#{map_def[:key]}"
  elsif %w{id parent_id project_id section_id user_id}.include?(field_name) ||
    (Node.safe_method_type([field_name]) && Node.column_names.include?(field_name))
    "#{table}.#{field_name}"
  elsif @query.tables.include?('links') &&
       (key = field_name[/^l_(.+)$/,1]) &&
       (key == 'id' ||
        Zena::Use::Relations::LINK_ATTRIBUTES.include?(key.to_sym))
    "#{table('links')}.#{key}"
  elsif field_name == 'random'
    Zena::Db.sql_function(field_name, nil)
  else
    # property or real column

    # FIXME !!!! Why does this happen ?
    return nil if @query.main_class.columns.kind_of?(Array)


    column = @query.main_class.columns[field_name]
    if column && column.indexed?
      if column.index == true
        group_name = column.type
      elsif column.index =~ Property::Index::FIELD_INDEX_REGEXP
        # field in nodes
        return "#{table}.#{$1}"
      else
        group_name = column.index
      end

      index_table = @query.main_class.real_class.index_table_name(group_name)

      # We use the add_key_value_table rule to avoid inserting the
      # same index access twice.

      tbl = add_key_value_table(group_name, index_table, field_name) do |tbl_name|
        # This block is only executed once
        on_clause = "#{tbl_name}.node_id = #{table}.id AND #{tbl_name}.key = #{quote(field_name)}"
        if group_name.to_s =~ /^ml_/
          on_clause << " AND #{tbl_name}.lang = #{quote(visitor.lang)}"
        end
        # no need for distinct, the new table makes a 1-1 relation
        # ON CLAUSE
        on_clause
        
      end

      "#{tbl}.value"
    else
      super # raises an error
    end
  end
end