!Fixed: Player data wasn't loading. Added: Event when called when a player used an attribute.

src/main/java/net/Indyuce/mmocore/api/event/PlayerAttributeUseEvent.java

@@ -0,0 +1,22 @@
+package net.Indyuce.mmocore.api.event;
+
+import net.Indyuce.mmocore.api.player.PlayerData;
+import org.bukkit.event.HandlerList;
+
+public class PlayerAttributeUseEvent extends PlayerDataEvent{
+    private static final HandlerList handlers = new HandlerList();
+
+    public PlayerAttributeUseEvent(PlayerData playerData) {
+        super(playerData);
+    }
+
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}

src/main/java/net/Indyuce/mmocore/api/player/PlayerData.java

@@ -92,16 +92,11 @@ public class PlayerData extends OfflinePlayerData {
 		this.questData = new PlayerQuests(this);
 	}
 
-	/*
-	 * easily solves some issues where other plugins use PlayerData.get
-	 */
-	public static final PlayerData NOT_LOADED = new PlayerData();
-
 	@Deprecated
 	private PlayerData() {
 		super(UUID.randomUUID());
 
-		mmoData = new MMOPlayerData(null, null);
+		mmoData = new MMOPlayerData();
 		playerStats = new PlayerStats(this);
 		questData = new PlayerQuests(this, null);
 	}
@@ -447,7 +442,7 @@ public class PlayerData extends OfflinePlayerData {
 	 * 
 	 * @param value  Experience to give the player
 	 * @param source How the player earned experience
-	 * @param loc    Location used to display the hologram. If it's null, no
+	 * @param hologramLocation    Location used to display the hologram. If it's null, no
 	 *               hologram will be displayed
 	 */
 	public void giveExperience(int value, EXPSource source, @Nullable Location hologramLocation) {
@@ -789,6 +784,11 @@ public class PlayerData extends OfflinePlayerData {
 		return cast;
 	}
 
+	@Override
+	public int hashCode() {
+		return mmoData.hashCode();
+	}
+
 	@Override
 	public boolean equals(Object obj) {
 		return obj instanceof PlayerData && ((PlayerData) obj).getUniqueId().equals(getUniqueId());

src/main/java/net/Indyuce/mmocore/comp/placeholder/RPGPlaceholders.java

@@ -13,8 +13,6 @@ import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.attribute.Attribute;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 
 public class RPGPlaceholders extends PlaceholderExpansion {
@@ -45,7 +43,7 @@ public class RPGPlaceholders extends PlaceholderExpansion {
 
 	@SuppressWarnings("DuplicateExpressions")
 	@Override
-	public String onRequest(@Nullable OfflinePlayer player, @NotNull String identifier) {
+	public String onRequest(OfflinePlayer player, String identifier) {
 		PlayerData playerData = PlayerData.get(player);
 
 		if (identifier.equals("mana_icon"))

src/main/java/net/Indyuce/mmocore/gui/AttributeView.java

@@ -1,5 +1,7 @@
 package net.Indyuce.mmocore.gui;
 
+import net.Indyuce.mmocore.api.event.PlayerAttributeUseEvent;
+import org.bukkit.Bukkit;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.event.inventory.InventoryClickEvent;
 
@@ -127,6 +129,10 @@ public class AttributeView extends EditableInventory {
 				playerData.giveAttributePoints(-1);
 				MMOCore.plugin.configManager.getSimpleMessage("attribute-level-up", "attribute", attribute.getName(), "level", "" + ins.getBase()).send(player);
 				MMOCore.plugin.soundManager.play(getPlayer(), SoundManager.SoundEvent.LEVEL_ATTRIBUTE);
+
+				PlayerAttributeUseEvent playerAttributeUseEvent = new PlayerAttributeUseEvent(playerData);
+				Bukkit.getServer().getPluginManager().callEvent(playerAttributeUseEvent);
+
 				open();
 			}
 		}

src/main/java/net/Indyuce/mmocore/listener/PlayerListener.java

@@ -12,6 +12,7 @@ import org.bukkit.event.entity.EntityRegainHealthEvent;
 import org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason;
 import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
 import org.bukkit.event.player.PlayerJoinEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
 
@@ -20,15 +21,21 @@ import net.Indyuce.mmocore.api.event.PlayerRegenResourceEvent;
 import net.Indyuce.mmocore.api.player.PlayerData;
 import net.Indyuce.mmocore.api.player.profess.resource.PlayerResource;
 import net.Indyuce.mmocore.gui.api.PluginInventory;
+import org.bukkit.scheduler.BukkitRunnable;
 
 public class PlayerListener implements Listener {
 
-	/*
-	 * initialize player data
-	 */
-	@EventHandler(priority = EventPriority.LOW)
-	public void a(PlayerJoinEvent event) {
-		MMOCore.plugin.dataProvider.getDataManager().setup(event.getPlayer().getUniqueId());
+    /*
+    	We load our player data.
+     */
+	@EventHandler(priority = EventPriority.NORMAL)
+	public void playerLoadingEvent(PlayerJoinEvent e) {
+		new BukkitRunnable() {
+			@Override
+			public void run() {
+				MMOCore.plugin.dataProvider.getDataManager().setup(e.getPlayer().getUniqueId());
+			}
+		}.runTaskAsynchronously(MMOCore.plugin);
 	}
 
 	/*

src/main/java/net/Indyuce/mmocore/manager/data/PlayerDataManager.java

@@ -1,9 +1,6 @@
 package net.Indyuce.mmocore.manager.data;
 
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
+import java.util.*;
 
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
@@ -14,9 +11,11 @@ import net.Indyuce.mmocore.api.event.PlayerDataLoadEvent;
 import net.Indyuce.mmocore.api.player.OfflinePlayerData;
 import net.Indyuce.mmocore.api.player.PlayerData;
 import io.lumine.mythic.lib.api.player.MMOPlayerData;
+import org.bukkit.scheduler.BukkitRunnable;
 
 public abstract class PlayerDataManager {
-	private final static Map<UUID, PlayerData> data = new HashMap<>();
+	private final static Map<UUID, PlayerData> data = Collections.synchronizedMap(new HashMap<>());
+
 	private DefaultPlayerData defaultData = new DefaultPlayerData(1, 0, 0, 0, 0);
 
 	public PlayerData get(OfflinePlayer player) {
@@ -33,34 +32,29 @@ public abstract class PlayerDataManager {
 
 	public abstract OfflinePlayerData getOffline(UUID uuid);
 
-	public PlayerData setup(UUID uuid) {
-		/*
-		 * Setup playerData based on loadData method to support both MySQL and
-		 * YAML data storage
-		 */
-		PlayerData playerData = data.get(uuid);
-		if (playerData == null) {
-			playerData = data.put(uuid, new PlayerData(MMOPlayerData.get(uuid)));
+	public PlayerData setup(UUID uniqueId) {
+		return data.compute(uniqueId, (uuid, searchData) -> {
+			if (searchData == null) {
+				PlayerData playerData = new PlayerData(MMOPlayerData.get(uniqueId));
 
-			/*
-			 * Loads player data and ONLY THEN refresh the player statistics and
-			 * calls the load event on the MAIN thread
-			 */
-			Bukkit.getScheduler().runTaskAsynchronously(MMOCore.plugin, () -> {
-				PlayerData loaded = PlayerData.get(uuid);
-				if (!loaded.isOnline())
-					return;
-				loadData(loaded);
-				Bukkit.getScheduler().runTask(MMOCore.plugin, () -> {
-					if (loaded.isOnline())
-						Bukkit.getPluginManager().callEvent(new PlayerDataLoadEvent(loaded));
-				});
-				loaded.getStats().updateStats();
-			});
-		}
-		return playerData;
+				loadData(playerData);
+				playerData.getStats().updateStats();
+
+				// We call the player data load event. TODO: Convert this event to async.
+				new BukkitRunnable() {
+					@Override
+					public void run() {
+						Bukkit.getPluginManager().callEvent(new PlayerDataLoadEvent(playerData));
+					}
+				}.runTask(MMOCore.plugin);
+
+				return playerData;
+			} else return searchData;
+
+		});
 	}
 
+
 	public DefaultPlayerData getDefaultData() {
 		return defaultData;
 	}

src/main/resources/plugin.yml

@@ -4,7 +4,7 @@ main: net.Indyuce.mmocore.MMOCore
 author: Indyuce
 description: ${project.description}
 loadbefore: [MMOItems]
-depend: [MMOLib]
+depend: [MythicLib]
 softdepend: [Vault,MythicMobs,PlaceholderAPI,Residence]
 api-version: 1.13
 commands: