How to format a case class which its paramters is more than 22

Question

well,I have looked over the playframework document about json transformers ,it worked well until my case class's parameters more than 22 . When the parameters of case class is more than 22,An error which tell me that the case class's unapplay function couldn't be found has occurred

Answer 1

First, if you have a case class with 22 fields, it is a sign of a incorrect bad. However, if you have no choice to refactor your code you can do the following:

for example here is my case class:

case class MyClass(arg1: String, arg2: String, arg3: String)

I can rewrite the above class with two fields as follows:

case class Helper(arg1: String, arg2: String)
case class MyClass(arg12: Helper, arg3: String)

So by factoring out the first two argument in a case class, MyClass will have two fields instead of three. Of course I demonstrated it just by three fields because demonstrating it with 22 fields is tedious ;).