Added registerExpansion method. Placeholder map interaction methods now return immutable objects

src/main/java/me/clip/placeholderapi/PlaceholderAPI.java

@@ -20,13 +20,14 @@
  */
 package me.clip.placeholderapi;
 
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import me.clip.placeholderapi.events.ExpansionRegisterEvent;
 import me.clip.placeholderapi.events.ExpansionUnregisterEvent;
-import me.clip.placeholderapi.events.PlaceholderHookUnloadEvent;
 import me.clip.placeholderapi.expansion.PlaceholderExpansion;
 import me.clip.placeholderapi.expansion.Relational;
 import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
-import org.bukkit.ChatColor;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.Plugin;
 
@@ -49,17 +50,18 @@ public class PlaceholderAPI {
 
     /**
      * check if a specific placeholder identifier is currently registered
+     *
      * @param identifier to check
      * @return true if identifier is already registered
      */
     public static boolean isRegistered(String identifier) {
-		return !placeholders.isEmpty() && getRegisteredIdentifiers().stream().filter(id -> id.equalsIgnoreCase(identifier)).findFirst().orElse(null) != null;
+        return getRegisteredIdentifiers().stream().filter(id -> id.equalsIgnoreCase(identifier)).findFirst().orElse(null) != null;
     }
 
     /**
      * Register a new placeholder hook
-	 * @param identifier Identifier of the placeholder -> "%(identifier)_(args...)%
      *
+     * @param identifier      Identifier of the placeholder -> "%(identifier)_(args...)%
      * @param placeholderHook implementing class that contains the onPlaceholderRequest method which is called when a value is needed for the specific placeholder
      * @return true if the hook was successfully registered, false if there is already a hook registered for the specified identifier
      */
@@ -73,6 +75,7 @@ public class PlaceholderAPI {
 
     /**
      * unregister a placeholder hook by identifier
+     *
      * @param identifier the identifier for the placeholder hook to unregister
      * @return true if the placeholder hook was successfully unregistered, false if there was no placeholder hook registered for the identifier specified
      */
@@ -83,27 +86,30 @@ public class PlaceholderAPI {
 
     /**
      * Get all registered placeholder identifiers
+     *
      * @return all registered placeholder identifiers
      */
     public static Set<String> getRegisteredIdentifiers() {
-		if (placeholders.isEmpty()) return new HashSet<>();
+        return ImmutableSet.copyOf(placeholders.keySet());
-		return new HashSet<>(placeholders.keySet());
     }
 
     /**
      * Get map of registered placeholders
+     *
      * @return copy of the internal placeholder map
      */
     public static Map<String, PlaceholderHook> getPlaceholders() {
-		return new HashMap<>(placeholders);
+        return ImmutableMap.copyOf(placeholders);
     }
 
     public static Set<PlaceholderExpansion> getExpansions() {
-		return getPlaceholders().values().stream().filter(PlaceholderExpansion.class::isInstance).map(PlaceholderExpansion.class::cast).collect(Collectors.toCollection(HashSet::new));
+        Set<PlaceholderExpansion> set = getPlaceholders().values().stream().filter(PlaceholderExpansion.class::isInstance).map(PlaceholderExpansion.class::cast).collect(Collectors.toCollection(HashSet::new));
+        return ImmutableSet.copyOf(set);
     }
 
     /**
      * check if a String contains any PlaceholderAPI placeholders
+     *
      * @param text String to check
      * @return true if String contains any registered placeholder identifiers, false otherwise
      */
@@ -113,6 +119,7 @@ public class PlaceholderAPI {
 
     /**
      * check if a String contains any PlaceholderAPI bracket placeholders
+     *
      * @param text String to check
      * @return true if String contains any registered placeholder identifiers, false otherwise
      */
@@ -123,6 +130,7 @@ public class PlaceholderAPI {
     /**
      * set placeholders in the list<String> text provided
      * placeholders are matched with the pattern {<placeholder>} when set with this method
+     *
      * @param p    Player to parse the placeholders for
      * @param text text to set the placeholder values in
      * @return modified list with all placeholders set to the corresponding values
@@ -134,6 +142,7 @@ public class PlaceholderAPI {
     /**
      * set placeholders in the list<String> text provided
      * placeholders are matched with the pattern %(identifier)_(params)>% when set with this method
+     *
      * @param p    Player to parse the placeholders for
      * @param text text to parse the placeholder values in
      * @return modified list with all placeholders set to the corresponding values
@@ -145,22 +154,20 @@ public class PlaceholderAPI {
     /**
      * set placeholders in the list<String> text provided
      * placeholders are matched with the pattern %(identifier)_(params)>% when set with this method
+     *
      * @param p    Player to parse the placeholders for
      * @param text text to parse the placeholder values in
      * @return modified list with all placeholders set to the corresponding values
      */
     public static List<String> setPlaceholders(Player p, List<String> text, Pattern pattern) {
         if (text == null) return null;
-        List<String> temp = new ArrayList<>();
+        return text.stream().map(line -> setPlaceholders(p, line, pattern)).collect(Collectors.toList());
-        text.forEach(line -> {
-            temp.add(setPlaceholders(p, line, pattern));
-        });
-        return temp;
     }
 
     /**
      * set placeholders in the text specified
      * placeholders are matched with the pattern {<placeholder>} when set with this method
+     *
      * @param player Player to parse the placeholders for
      * @param text   text to parse the placeholder values to
      * @return modified text with all placeholders set to the corresponding values
@@ -172,6 +179,7 @@ public class PlaceholderAPI {
     /**
      * set placeholders in the text specified
      * placeholders are matched with the pattern %<(identifier)_(params)>% when set with this method
+     *
      * @param player Player to parse the placeholders for
      * @param text   text to parse the placeholder values to
      * @return text with all placeholders set to the corresponding values
@@ -183,6 +191,7 @@ public class PlaceholderAPI {
     /**
      * set placeholders in the text specified
      * placeholders are matched with the pattern %<(identifier)_(params)>% when set with this method
+     *
      * @param player             Player to parse the placeholders for
      * @param text               text to parse the placeholder values to
      * @param placeholderPattern the pattern to match placeholders to. Capture group 1 must contain an underscore separating the identifier from the params
@@ -198,7 +207,7 @@ public class PlaceholderAPI {
             int index = format.indexOf("_");
             if (index <= 0 || index >= format.length()) continue;
             String identifier = format.substring(0, index).toLowerCase();
-			String params = format.substring(index+1);
+            String params = format.substring(index + 1);
             if (hooks.containsKey(identifier)) {
                 String value = hooks.get(identifier).onPlaceholderRequest(player, params);
                 if (value != null) {
@@ -212,6 +221,7 @@ public class PlaceholderAPI {
     /**
      * set relational placeholders in the text specified
      * placeholders are matched with the pattern %<rel_(identifier)_(params)>% when set with this method
+     *
      * @param one  Player to compare
      * @param two  Player to compare
      * @param text text to parse the placeholder values to
@@ -219,16 +229,13 @@ public class PlaceholderAPI {
      */
     public static List<String> setRelationalPlaceholders(Player one, Player two, List<String> text) {
         if (text == null) return null;
-		List<String> temp = new ArrayList<>();
+        return text.stream().map(line -> setRelationalPlaceholders(one, two, line)).collect(Collectors.toList());
-		text.forEach(line -> {
-			temp.add(setRelationalPlaceholders(one, two, line));
-		});
-		return temp;
     }
 
     /**
      * set relational placeholders in the text specified
      * placeholders are matched with the pattern %<rel_(identifier)_(params)>% when set with this method
+     *
      * @param one  Player to compare
      * @param two  Player to compare
      * @param text text to parse the placeholder values to
@@ -244,7 +251,7 @@ public class PlaceholderAPI {
             int index = format.indexOf("_");
             if (index <= 0 || index >= format.length()) continue;
             String identifier = format.substring(0, index).toLowerCase();
-		    String params = format.substring(index+1);
+            String params = format.substring(index + 1);
             if (hooks.containsKey(identifier)) {
                 if (!(hooks.get(identifier) instanceof Relational)) {
                     continue;
@@ -282,6 +289,14 @@ public class PlaceholderAPI {
         });
     }
 
+    public static boolean registerExpansion(PlaceholderExpansion ex) {
+        if (registerPlaceholderHook(ex.getIdentifier(), ex)) {
+            Bukkit.getPluginManager().callEvent(new ExpansionRegisterEvent(ex));
+            return true;
+        }
+        return false;
+    }
+
     public static boolean unregisterExpansion(PlaceholderExpansion ex) {
         if (unregisterPlaceholderHook(ex.getIdentifier())) {
             Bukkit.getPluginManager().callEvent(new ExpansionUnregisterEvent(ex));
@@ -306,14 +321,17 @@ public class PlaceholderAPI {
     public static Set<String> getRegisteredPlaceholderPlugins() {
         return getRegisteredIdentifiers();
     }
+
     @Deprecated
     public static Set<String> getExternalPlaceholderPlugins() {
         return null;
     }
+
     @Deprecated
     public static boolean registerPlaceholderHook(Plugin plugin, PlaceholderHook placeholderHook) {
         return plugin != null && registerPlaceholderHook(plugin.getName(), placeholderHook);
     }
+
     @Deprecated
     public static boolean unregisterPlaceholderHook(Plugin plugin) {
         return plugin != null && unregisterPlaceholderHook(plugin.getName());