It will be a lot easier for mutators to add their own screens to the web-admin. The only thing needed is to add a data-provider entry to the mutator ini file and to create a page handler class (it must implement a dedicated interface).
Here is an example of such a data-provider:
[MyMutator ROUIDataProvider_MenuEntry]
URI=/mutators/mymutator
ClassName=MyMutator.MyMutator.SettingsClass
Title=MyMutatorTitle
Description=Manages the my-mutator configuration
The above example will add a menu entry just below the
Mutators entry with the title
MyMutatorTitle.
This means that you can directly access a mutator page from out of the menu and you do not need to go to the Mutators page and to select it there in the drop-down box.
This approach also opens the door for replacing a stock RS2 page by a mutator page. In other words you can remake for instance the Current - Players page with a mutator and let it be accessed directly from the stock menu entry.
Here an example on how to set-up the data-provider for such a replacement page:
[MyCurrentPlayers ROUIDataProvider_MenuEntry]
URI=/current/players
ClassName=MyMutator.MyCurrentPlayers
The
MyCurrentPlayers class within your
MyMutator will from that moment on be serving the
ServerAdmin/current/players URI.
For the handler class itself you can use all the tools available for the stock screens. Thus you can even write HTML page with <%label%> replacement/substitution tags in it.
Regarding the template mentioned by dibbler, the intention is to add that one to the RS2 SDK as a normal class (because if in the stock base, then it's not needed as a template).