Added PlaceholderAPI support 🎉

pom.xml

@@ -60,6 +60,10 @@
 			<id>vault-repo</id>
 			<url>http://nexus.hc.to/content/repositories/pub_releases</url>
 		</repository>
+		<repository>
+			<id>placeholderapi</id>
+			<url>http://repo.extendedclip.com/content/repositories/placeholderapi/</url>
+		</repository>
 	</repositories>
 
 	<dependencies>
@@ -108,6 +112,13 @@
 			<version>1.7</version>
 			<scope>provided</scope>
 		</dependency>
+		<!-- Placeholders -->
+		<dependency>
+			<groupId>me.clip</groupId>
+			<artifactId>placeholderapi</artifactId>
+			<version>2.9.2</version>
+			<scope>provided</scope>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/world/bentobox/bentobox/BentoBox.java

@@ -12,6 +12,7 @@ import world.bentobox.bentobox.api.configuration.WorldSettings;
 import world.bentobox.bentobox.api.events.BentoBoxReadyEvent;
 import world.bentobox.bentobox.api.user.Notifier;
 import world.bentobox.bentobox.commands.BentoBoxCommand;
+import world.bentobox.bentobox.hooks.PlaceholderAPIHook;
 import world.bentobox.bentobox.hooks.VaultHook;
 import world.bentobox.bentobox.listeners.BannedVisitorCommands;
 import world.bentobox.bentobox.listeners.BlockEndDragon;
@@ -27,6 +28,7 @@ import world.bentobox.bentobox.managers.HooksManager;
 import world.bentobox.bentobox.managers.IslandWorldManager;
 import world.bentobox.bentobox.managers.IslandsManager;
 import world.bentobox.bentobox.managers.LocalesManager;
+import world.bentobox.bentobox.managers.PlaceholdersManager;
 import world.bentobox.bentobox.managers.PlayersManager;
 import world.bentobox.bentobox.managers.RanksManager;
 import world.bentobox.bentobox.managers.SchemsManager;
@@ -52,6 +54,7 @@ public class BentoBox extends JavaPlugin {
     private RanksManager ranksManager;
     private SchemsManager schemsManager;
     private HooksManager hooksManager;
+    private PlaceholdersManager placeholdersManager;
 
     // Settings
     private Settings settings;
@@ -143,6 +146,10 @@ public class BentoBox extends JavaPlugin {
             // Load hooks
             hooksManager = new HooksManager(this);
             hooksManager.registerHook(new VaultHook());
+            hooksManager.registerHook(new PlaceholderAPIHook());
+
+            // Setup the Placeholders manager
+            placeholdersManager = new PlaceholdersManager(this);
 
             // Fire plugin ready event
             isLoaded = true;

src/main/java/world/bentobox/bentobox/api/placeholders/PlaceholderReplacer.java

@@ -0,0 +1,8 @@
+package world.bentobox.bentobox.api.placeholders;
+
+import world.bentobox.bentobox.api.user.User;
+
+public interface PlaceholderReplacer {
+
+    String onReplace(User user);
+}

src/main/java/world/bentobox/bentobox/hooks/PlaceholderAPIHook.java

@@ -0,0 +1,128 @@
+package world.bentobox.bentobox.hooks;
+
+import me.clip.placeholderapi.expansion.PlaceholderExpansion;
+import org.bukkit.entity.Player;
+import world.bentobox.bentobox.BentoBox;
+import world.bentobox.bentobox.api.addons.Addon;
+import world.bentobox.bentobox.api.hooks.Hook;
+import world.bentobox.bentobox.api.placeholders.PlaceholderReplacer;
+import world.bentobox.bentobox.api.user.User;
+
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * Provides implementations and interfacing needed to register and get placeholders from PlaceholderAPI.
+ *
+ * @author Poslovitch
+ */
+public class PlaceholderAPIHook extends Hook {
+
+    private BentoBoxPlaceholderExpansion bentoboxExpansion;
+    private Map<Addon, AddonPlaceholderExpansion> addonsExpansions;
+
+    public PlaceholderAPIHook() {
+        super("PlaceholderAPI");
+        this.bentoboxExpansion = new BentoBoxPlaceholderExpansion(BentoBox.getInstance());
+        this.addonsExpansions = new HashMap<>();
+    }
+
+    @Override
+    public boolean hook() {
+        return bentoboxExpansion.canRegister() && bentoboxExpansion.register();
+    }
+
+    @Override
+    public String getFailureCause() {
+        return "could not register BentoBox's expansion";
+    }
+
+    public void registerBentoBoxPlaceholder(String placeholder, PlaceholderReplacer replacer) {
+        bentoboxExpansion.registerPlaceholder(placeholder, replacer);
+    }
+
+    public void registerAddonPlaceholder(Addon addon, String placeholder, PlaceholderReplacer replacer) {
+        // Check if the addon expansion does not exist
+        if (!addonsExpansions.containsKey(addon)) {
+            AddonPlaceholderExpansion addonPlaceholderExpansion = new AddonPlaceholderExpansion(addon);
+            addonPlaceholderExpansion.register();
+            addonsExpansions.put(addon, addonPlaceholderExpansion);
+        }
+
+        addonsExpansions.get(addon).registerPlaceholder(placeholder, replacer);
+    }
+
+    abstract class BasicPlaceholderExpansion extends PlaceholderExpansion {
+        private Map<String, PlaceholderReplacer> placeholders;
+
+        BasicPlaceholderExpansion() {
+            this.placeholders = new HashMap<>();
+        }
+
+        @Override
+        public String getIdentifier() {
+            return getName().toLowerCase(Locale.ENGLISH);
+        }
+
+        void registerPlaceholder(String placeholder, PlaceholderReplacer replacer) {
+            placeholders.putIfAbsent(placeholder, replacer);
+        }
+
+        @Override
+        public String onPlaceholderRequest(Player p, String placeholder) {
+            User user = User.getInstance(p);
+
+            if (placeholders.containsKey(placeholder)) {
+                return placeholders.get(placeholder).onReplace(user);
+            }
+            return null;
+        }
+    }
+
+    class BentoBoxPlaceholderExpansion extends BasicPlaceholderExpansion {
+        private BentoBox plugin;
+
+        BentoBoxPlaceholderExpansion(BentoBox plugin) {
+            this.plugin = plugin;
+        }
+
+        @Override
+        public String getName() {
+            return plugin.getName();
+        }
+
+        @Override
+        public String getAuthor() {
+            return "Tastybento and Poslovitch";
+        }
+
+        @Override
+        public String getVersion() {
+            return plugin.getDescription().getVersion();
+        }
+    }
+
+    class AddonPlaceholderExpansion extends BasicPlaceholderExpansion {
+        private Addon addon;
+
+        AddonPlaceholderExpansion(Addon addon) {
+            this.addon = addon;
+        }
+
+        @Override
+        public String getName() {
+            return addon.getDescription().getName();
+        }
+
+        @Override
+        public String getAuthor() {
+            return addon.getDescription().getAuthors().get(0);
+        }
+
+        @Override
+        public String getVersion() {
+            return addon.getDescription().getVersion();
+        }
+    }
+}

src/main/java/world/bentobox/bentobox/managers/PlaceholdersManager.java

@@ -0,0 +1,35 @@
+package world.bentobox.bentobox.managers;
+
+import world.bentobox.bentobox.BentoBox;
+import world.bentobox.bentobox.api.addons.Addon;
+import world.bentobox.bentobox.api.placeholders.PlaceholderReplacer;
+import world.bentobox.bentobox.hooks.PlaceholderAPIHook;
+
+public class PlaceholdersManager {
+
+    private BentoBox plugin;
+
+    public PlaceholdersManager(BentoBox plugin) {
+        this.plugin = plugin;
+    }
+
+    public void registerPlaceholder(String placeholder, PlaceholderReplacer replacer) {
+        // Register it in PlaceholderAPI
+        plugin.getHooks().getHook("PlaceholderAPI").ifPresent(hook -> {
+            PlaceholderAPIHook placeholderAPIHook = (PlaceholderAPIHook) hook;
+            placeholderAPIHook.registerBentoBoxPlaceholder(placeholder, replacer);
+        });
+    }
+
+    public void registerPlaceholder(Addon addon, String placeholder, PlaceholderReplacer replacer) {
+        if (addon == null) {
+            registerPlaceholder(placeholder, replacer);
+            return;
+        }
+        // Register it in PlaceholderAPI
+        plugin.getHooks().getHook("PlaceholderAPI").ifPresent(hook -> {
+            PlaceholderAPIHook placeholderAPIHook = (PlaceholderAPIHook) hook;
+            placeholderAPIHook.registerAddonPlaceholder(addon, placeholder, replacer);
+        });
+    }
+}