[Missing doc] How to generate the table for Custom Version Classes?

[qwert321]

With README(v3.0.0rc), section "Custom Version Classes", I didn't find any text about how to generate the database table for Custom Version Classes.

1. Need I run some rake script to generate migration script, then run the migration script?
   then, what's rake commands to do it?
2. Or the same fields for Custom Version Classe table as for the model table?
3. Or the same fields for Custom Version Classe table as for the generic Version table?

Thanks

[batter]

As that section of the README insinuates, one way to do it is to create a migration that is identical to the one PaperTrail generates for your versions table, and then use that (number 3 in your suggested methods). Another easy way to do it would be to use Single Table Inheritance, and make your custom version class a sub-class of the PaperTrail::Version class. Simply add an extra field to your migration for the versions table like so:

t.string     :type

And then subclass your custom version model under the PaperTrail::Version class like the README suggests, but don't use the self.table_name option on the model. Rails will then know to use the type column as the indicator for which type of version your using. (But this will result in all version types being stored in the versions table, which may not be desired). Those are the options that I would recommend.

Here is an example in the test suite of one way to generate a custom versions table.

[batter]

Oh, there is also a 3rd way to make a custom version class, and that involves using the new PaperTrail::VersionConcern module. Please see the discussion on #289 for more details about usage of that module.