When should you really use the visitor pattern

Question

Ok before marking this as a duplicate let me clarify myself. I\'m reading about the visitor pattern and its applicable uses.

I\'ve stumbled upon this post: When should I

Answer 1

you can use the visitor pattern to design a db saver, like shown in this diagram here: class diagram for an object saver in different dbs

you can choose what db to use, the client class will look similar to this:

    Visitor mongosaver = new MongodbSaver();
    Visitable user = new User();
    //save the user object using mongodb saver
    user.accept(mongosaver);
    Visitable post = new BlogPost();
    Visitor mysqlsaver = new MysqlSaver();
    //save the BlogPost using Mysql saver
    post.accept(mysqlsaver);

you can refer to this also: https://www.oodesign.com/visitor-pattern.html