original_string: protected function _foreignOnClause($on)
      {
          if ($on === TableSchema::ACTION_SET_NULL) {
              return 'SET NULL';
          }
          if ($on === TableSchema::ACTION_SET_DEFAULT) {
              return 'SET DEFAULT';
          }
          if ($on === TableSchema::ACTION_CASCADE) {
              return 'CASCADE';
          }
          if ($on === TableSchema::ACTION_RESTRICT) {
              return 'RESTRICT';
          }
          if ($on === TableSchema::ACTION_NO_ACTION) {
              return 'NO ACTION';
          }
      }
code: protected function _foreignOnClause($on)
      {
          if ($on === TableSchema::ACTION_SET_NULL) {
              return 'SET NULL';
          }
          if ($on === TableSchema::ACTION_SET_DEFAULT) {
              return 'SET DEFAULT';
          }
          if ($on === TableSchema::ACTION_CASCADE) {
              return 'CASCADE';
          }
          if ($on === TableSchema::ACTION_RESTRICT) {
              return 'RESTRICT';
          }
          if ($on === TableSchema::ACTION_NO_ACTION) {
              return 'NO ACTION';
          }
      }
code_tokens: protected function _foreignOnClause ( $ on ) { if ( $ on === TableSchema :: ACTION_SET_NULL ) { return 'SET NULL' ; } if ( $ on === TableSchema :: ACTION_SET_DEFAULT ) { return 'SET DEFAULT' ; } if ( $ on === TableSchema :: ACTION_CASCADE ) { return 'CASCADE' ; } if ( $ on === TableSchema :: ACTION_RESTRICT ) { return 'RESTRICT' ; } if ( $ on === TableSchema :: ACTION_NO_ACTION ) { return 'NO ACTION' ; } }
docstring: Generate an ON clause for a foreign key.
  
  @param string|null $on The on clause
  @return string
docstring_tokens: Generate an ON clause for a foreign key .