PlayerChatEvent: introduce new formatting API

this API is simultaneously more powerful and cleaner than the previous system.
The previous system relied on undocumented behaviour and was limited to non-localizable strings.

This enables custom servers to implement their own chat formats (e.g. containing localizable tags) which will be displayed in each player's own language (once per-player language has been properly implemented, anyway).

src/event/player/PlayerChatEvent.php

@@ -26,7 +26,7 @@ namespace pocketmine\event\player;
 use pocketmine\command\CommandSender;
 use pocketmine\event\Cancellable;
 use pocketmine\event\CancellableTrait;
-use pocketmine\lang\KnownTranslationKeys;
+use pocketmine\player\chat\ChatFormatter;
 use pocketmine\player\Player;
 use pocketmine\utils\Utils;
 
@@ -43,7 +43,7 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 		Player $player,
 		protected string $message,
 		protected array $recipients,
-		protected string $format = KnownTranslationKeys::CHAT_TYPE_TEXT
+		protected ChatFormatter $formatter
 	){
 		$this->player = $player;
 	}
@@ -63,12 +63,12 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 		$this->player = $player;
 	}
 
-	public function getFormat() : string{
-		return $this->format;
+	public function getFormatter() : ChatFormatter{
+		return $this->formatter;
 	}
 
-	public function setFormat(string $format) : void{
-		$this->format = $format;
+	public function setFormatter(ChatFormatter $formatter) : void{
+		$this->formatter = $formatter;
 	}
 
 	/**

src/player/Player.php

@@ -114,6 +114,7 @@ use pocketmine\permission\DefaultPermissionNames;
 use pocketmine\permission\DefaultPermissions;
 use pocketmine\permission\PermissibleBase;
 use pocketmine\permission\PermissibleDelegateTrait;
+use pocketmine\player\chat\StandardChatFormatter;
 use pocketmine\Server;
 use pocketmine\timings\Timings;
 use pocketmine\utils\AssumptionFailedError;
@@ -1445,10 +1446,10 @@ class Player extends Human implements CommandSender, ChunkListener, IPlayer{
 					$this->server->dispatchCommand($this, substr($messagePart, 1));
 					Timings::$playerCommand->stopTiming();
 				}else{
-					$ev = new PlayerChatEvent($this, $messagePart, $this->server->getBroadcastChannelSubscribers(Server::BROADCAST_CHANNEL_USERS));
+					$ev = new PlayerChatEvent($this, $messagePart, $this->server->getBroadcastChannelSubscribers(Server::BROADCAST_CHANNEL_USERS), new StandardChatFormatter());
 					$ev->call();
 					if(!$ev->isCancelled()){
-						$this->server->broadcastMessage($this->getServer()->getLanguage()->translateString($ev->getFormat(), [$ev->getPlayer()->getDisplayName(), $ev->getMessage()]), $ev->getRecipients());
+						$this->server->broadcastMessage($ev->getFormatter()->format($ev->getPlayer()->getDisplayName(), $ev->getMessage()), $ev->getRecipients());
 					}
 				}
 			}

src/player/chat/ChatFormatter.php

@@ -0,0 +1,38 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+ */
+
+declare(strict_types=1);
+
+namespace pocketmine\player\chat;
+
+use pocketmine\lang\Translatable;
+
+/**
+ * Formats chat messages for broadcasting. Used in PlayerChatEvent.
+ */
+interface ChatFormatter{
+	/**
+	 * Returns the formatted message to broadcast.
+	 * This can return a plain string (which will be used as-is) or a Translatable (which will be translated into
+	 * each recipient's language).
+	 */
+	public function format(string $username, string $message) : Translatable|string;
+}

src/player/chat/LegacyRawChatFormatter.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+ */
+
+declare(strict_types=1);
+
+namespace pocketmine\player\chat;
+
+use function str_replace;
+
+/**
+ * Legacy raw string chat formatter with the same behaviour as the old PlayerChatEvent::setFormat() API.
+ * The format string should contain the placeholders {%0} and {%1} for the username and message respectively.
+ */
+final class LegacyRawChatFormatter implements ChatFormatter{
+
+	public function __construct(
+		private string $format
+	){}
+
+	public function format(string $username, string $message) : string{
+		return str_replace(["{%0}", "{%1}"], [$username, $message], $this->format);
+	}
+}

src/player/chat/StandardChatFormatter.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+ */
+
+declare(strict_types=1);
+
+namespace pocketmine\player\chat;
+
+use pocketmine\lang\KnownTranslationFactory;
+use pocketmine\lang\Translatable;
+
+/**
+ * Standard chat formatter, formats messages in the default Minecraft way.
+ */
+final class StandardChatFormatter implements ChatFormatter{
+
+	public function format(string $username, string $message) : Translatable{
+		return KnownTranslationFactory::chat_type_text($username, $message);
+	}
+}