A method and navigation helper for generating constraint language codes for navigation in a constraint language editor. The constraint language editor generates model/instance-related constraint expressions according to the loaded model/instance and related constraints. The navigation is a path implementing the constraints. The method includes parsing the loaded model/instance; calculating a possible association related to the element through the type of the navigation-related element in the model/instance; and calculating a possible navigation path according to the association. A method for generating constraint language codes in a constraint language editor and the constraint language editor includes loading the model/instance; loading constraint patterns for storing parameters and a constraint code template; invoking corresponding helpers, according to the types of parameters stored in the constraint patterns; and generating constraint codes according to the generated parameters and the constraint code template.