[Added] Service interface for cross-mod communication

[m8f]

I've changed the implementation so the service iterator accepts partial name matches too.
So, modA1 defines "HealthService_A1", modA2 defines "HealthService_A2", modB searches for "HealthService" and finds both.

I had to remove the convenience method ServiceIterator.ServiceExists(). Now the only way to know if there are no Services found is to count how many times Next() returns not NULL.

I updated the PR, and here is the standalone preview:

service-new.zip

There are four directories in this archive, each is meant to be loaded separately, with service directory first.

[Major Cooke]

I'll implement this into QZDoom soon. Sorry for not responding sooner. Just been busy with RL but things have finally settled down.

[Major Cooke]

Alright, I gave this a thorough testing, and it seems to work as anticipated, which is very useful for cross mod messaging indeed. I hope Graf will consider merging this.

[Graf Zahl]

I'm going to take your word for it. I still can't wrap my head around a potential use case.

[Rachael]

I think the goal is to modularize addons. If there is a standard for addon-to-addon communication it makes it possible to establish a generic framework for them, or even any number of them, while making some parts of addons optional and reducing overall addon cross-dependency while increasing cross compatibility. That's just my guess, though.

[Major Cooke]

That guess is actually 100% accurate. Here's an example.

m8f's TargetSpy modification has a service that searches for MaxHealth named services that allows overriding the display of a monster's maximum health. As his mod is doing the searching anything with MaxHealth, this is how its set up.

Code: Select all • Expand view

static ui bool, int getMaxFromService(string className)
{
   ServiceIterator i = ServiceIterator.Find("MaxHealthService");

   Service s;
   if (s = i.Next())
   {
      String maxHealth = s.UiGet(className);
      if (maxHealth == "none")
      {
         return false, 0;
      }
      else
      {
         return true, maxHealth.ToInt();
      }
   }

   return false, 0;
}


Any mods that wish to make use of this just need to do something like this (note: there is a Get for Play and UIGet for UI scopes):

Code: Select all • Expand view

class StubMaxHealthService : Service
{
   override String UiGet(String className)
   {
      if (className ~== "DoomImp")
      {
         return "1000";
      }
      else
      {
         return "none";
      }
   }
}

And that's it.