added startup and shutdown events. fixes #586

docs/scarpet/api/Events.md

@@ -32,6 +32,13 @@ if it accepts required number of parameters.
 Global events will be handled once per app that is with `'global'` scope. With `player` scoped apps, each player instance
  is responsible independently from handling their events, so a global event may be executed multiple times for each player.
 
+### `__on_server_starts()`
+Event triggers after world is loaded and after all startup apps have started. It won't be triggered with `/reload`.
+
+### `__on_server_shuts_down()`
+Event triggers when the server started the shutdown process, before `__on_close()` is executed. Unlike `__on_close()`, it doesn't
+trigger with `/reload`.
+
 ### `__on_tick()`
 Event triggers at the beginning of each tick, located in the overworld. You can use `in_dimension()`
 to access other dimensions from there.

src/main/java/carpet/CarpetServer.java

@@ -102,9 +102,9 @@ public class CarpetServer implements ClientModInitializer,DedicatedServerModInit
 
     public static void onServerLoadedWorlds(MinecraftServer minecraftServer)
     {
+        HopperCounter.resetAll(minecraftServer);
         extensions.forEach(e -> e.onServerLoadedWorlds(minecraftServer));
         scriptServer.initializeForWorld();
-        HopperCounter.resetAll(minecraftServer);
     }
 
     public static void tick(MinecraftServer server)
@@ -169,9 +169,9 @@ public class CarpetServer implements ClientModInitializer,DedicatedServerModInit
 
     public static void onServerClosed(MinecraftServer server)
     {
+        if (scriptServer != null) scriptServer.onClose();
         ServerNetworkHandler.close();
         currentCommandDispatcher = null;
-        if (scriptServer != null) scriptServer.onClose();
 
         LoggerRegistry.stopLoggers();
         extensions.forEach(e -> e.onServerClosed(server));

src/main/java/carpet/script/CarpetEventServer.java

@@ -309,6 +309,30 @@ public class CarpetEventServer
             return events;
         }
 
+        public static final Event START = new Event("server_starts", 0, true)
+        {
+            @Override
+            public void onTick()
+            {
+                handler.call(Collections::emptyList, () ->
+                        CarpetServer.minecraft_server.getCommandSource().
+                                withWorld(CarpetServer.minecraft_server.getWorld(World.OVERWORLD))
+                );
+            }
+        };
+
+        public static final Event SHUTDOWN = new Event("server_shuts_down", 0, true)
+        {
+            @Override
+            public void onTick()
+            {
+                handler.call(Collections::emptyList, () ->
+                        CarpetServer.minecraft_server.getCommandSource().
+                                withWorld(CarpetServer.minecraft_server.getWorld(World.OVERWORLD))
+                );
+            }
+        };
+
         public static final Event TICK = new Event("tick", 0, true)
         {
             @Override

src/main/java/carpet/script/CarpetScriptServer.java

@@ -127,7 +127,7 @@ public class CarpetScriptServer
                 addScriptHost(server.getCommandSource(), moduleName, null, true, true, false);
             }
         }
-
+        CarpetEventServer.Event.START.onTick();
     }
 
     public Module getModule(String name, boolean allowLibraries)
@@ -489,6 +489,7 @@ public class CarpetScriptServer
 
     public void onClose()
     {
+        CarpetEventServer.Event.SHUTDOWN.onTick();
         for (ScriptHost host : modules.values())
         {
             host.onClose();