updated placeholderexpansion to define its own unregister method

src/main/java/me/clip/placeholderapi/commands/impl/local/CommandExpansionUnregister.java

@@ -39,7 +39,7 @@ public final class CommandExpansionUnregister extends PlaceholderCommand
 		}
 
 
-		final String message = !plugin.getLocalExpansionManager().unregister(expansion.get()) ?
+		final String message = !expansion.get().unregister() ?
 							   "&cFailed to unregister expansion: &f" :
 							   "&aSuccessfully unregistered expansion: &f";
 

src/main/java/me/clip/placeholderapi/expansion/PlaceholderExpansion.java

@@ -20,7 +20,6 @@
  */
 package me.clip.placeholderapi.expansion;
 
-import me.clip.placeholderapi.PlaceholderAPI;
 import me.clip.placeholderapi.PlaceholderAPIPlugin;
 import me.clip.placeholderapi.PlaceholderHook;
 import org.bukkit.Bukkit;
@@ -32,6 +31,7 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 public abstract class PlaceholderExpansion extends PlaceholderHook
 {
@@ -122,7 +122,7 @@ public abstract class PlaceholderExpansion extends PlaceholderHook
 	 */
 	public final boolean isRegistered()
 	{
-		return PlaceholderAPI.isRegistered(getIdentifier());
+		return getPlaceholderAPI().getLocalExpansionManager().findExpansionByIdentifier(getIdentifier()).map(it -> it.equals(this)).orElse(false);
 	}
 
 
@@ -141,12 +141,24 @@ public abstract class PlaceholderExpansion extends PlaceholderHook
 	 * Attempt to register this PlaceholderExpansion
 	 *
 	 * @return true if this expansion is now registered with PlaceholderAPI
+	 * @deprecated This is going to be final in the future, startup and shutdown logic will have their own methods soon.
 	 */
+	@Deprecated
 	public boolean register()
 	{
 		return canRegister() && getPlaceholderAPI().getLocalExpansionManager().register(this);
 	}
 
+	/**
+	 * Attempt to unregister this PlaceholderExpansion
+	 *
+	 * @return true if this expansion is now unregistered with PlaceholderAPI
+	 */
+	public final boolean unregister()
+	{
+		return getPlaceholderAPI().getLocalExpansionManager().unregister(this);
+	}
+
 
 	/**
 	 * Quick getter for the {@link PlaceholderAPIPlugin} instance
@@ -222,6 +234,36 @@ public abstract class PlaceholderExpansion extends PlaceholderHook
 		return section != null && section.contains(path);
 	}
 
+	@Override
+	public final boolean equals(final Object o)
+	{
+		if (this == o)
+		{
+			return true;
+		}
+		if (!(o instanceof PlaceholderExpansion))
+		{
+			return false;
+		}
+
+		final PlaceholderExpansion expansion = (PlaceholderExpansion) o;
+
+		return getIdentifier().equals(expansion.getIdentifier()) &&
+			   getAuthor().equals(expansion.getAuthor()) &&
+			   getVersion().equals(expansion.getVersion());
+	}
+
+	@Override
+	public final int hashCode()
+	{
+		return Objects.hash(getIdentifier(), getAuthor(), getVersion());
+	}
+
+	@Override
+	public final String toString()
+	{
+		return String.format("PlaceholderExpansion[name: '%s', author: '%s', version: '%s']", getName(), getAuthor(), getVersion());
+	}
 
 	// === Deprecated API ===
 

src/main/java/me/clip/placeholderapi/expansion/manager/LocalExpansionManager.java

@@ -124,6 +124,27 @@ public final class LocalExpansionManager implements Listener
 	}
 
 
+	public Optional<PlaceholderExpansion> register(@NotNull final Class<? extends PlaceholderExpansion> clazz)
+	{
+		try
+		{
+			final PlaceholderExpansion expansion = createExpansionInstance(clazz);
+			if (expansion == null || !expansion.register())
+			{
+				return Optional.empty();
+			}
+
+			return Optional.of(expansion);
+		}
+		catch (final LinkageError ex)
+		{
+			plugin.getLogger().severe("expansion class " + clazz.getSimpleName() + " is outdated: \n" +
+									  "Failed to load due to a [" + ex.getClass().getSimpleName() + "], attempted to use " + ex.getMessage());
+		}
+
+		return Optional.empty();
+	}
+
 	/**
 	 * Do not call this method yourself, use {@link PlaceholderExpansion#register()}
 	 */
@@ -188,7 +209,7 @@ public final class LocalExpansionManager implements Listener
 		}
 
 		final PlaceholderExpansion removed = expansions.get(expansion.getIdentifier());
-		if (removed != null && !unregister(removed))
+		if (removed != null && !removed.unregister())
 		{
 			return false;
 		}
@@ -228,27 +249,9 @@ public final class LocalExpansionManager implements Listener
 		return true;
 	}
 
-	public Optional<PlaceholderExpansion> register(@NotNull final Class<? extends PlaceholderExpansion> clazz)
+	/**
-	{
+	 * Do not call this method yourself, use {@link PlaceholderExpansion#unregister()}
-		try
+	 */
-		{
-			final PlaceholderExpansion expansion = createExpansionInstance(clazz);
-			if (expansion == null || !expansion.register())
-			{
-				return Optional.empty();
-			}
-
-			return Optional.of(expansion);
-		}
-		catch (final LinkageError ex)
-		{
-			plugin.getLogger().severe("expansion class " + clazz.getSimpleName() + " is outdated: \n" +
-									  "Failed to load due to a [" + ex.getClass().getSimpleName() + "], attempted to use " + ex.getMessage());
-		}
-
-		return Optional.empty();
-	}
-
 	public boolean unregister(@NotNull final PlaceholderExpansion expansion)
 	{
 		if (expansions.remove(expansion.getIdentifier()) == null)
@@ -314,7 +317,7 @@ public final class LocalExpansionManager implements Listener
 				continue;
 			}
 
-			unregister(expansion);
+			expansion.unregister();
 		}
 	}
 
@@ -399,7 +402,7 @@ public final class LocalExpansionManager implements Listener
 				continue;
 			}
 
-			unregister(expansion);
+			expansion.unregister();
 			plugin.getLogger().info("Unregistered placeholder expansion: " + expansion.getName());
 		}
 	}