Added support for creation-time validation of generator options, closes #2717

src/world/generator/GeneratorManager.php

@@ -34,35 +34,49 @@ final class GeneratorManager{
 	use SingletonTrait;
 
 	/**
-	 * @var string[] name => classname mapping
-	 * @phpstan-var array<string, class-string<Generator>>
+	 * @var GeneratorManagerEntry[] name => classname mapping
+	 * @phpstan-var array<string, GeneratorManagerEntry>
 	 */
 	private $list = [];
 
 	public function __construct(){
-		$this->addGenerator(Flat::class, "flat");
-		$this->addGenerator(Normal::class, "normal");
-		$this->addGenerator(Normal::class, "default");
-		$this->addGenerator(Nether::class, "hell");
-		$this->addGenerator(Nether::class, "nether");
+		$this->addGenerator(Flat::class, "flat", \Closure::fromCallable(function(string $preset) : ?InvalidGeneratorOptionsException{
+			if($preset === ""){
+				return null;
+			}
+			try{
+				FlatGeneratorOptions::parsePreset($preset);
+				return null;
+			}catch(InvalidGeneratorOptionsException $e){
+				return $e;
+			}
+		}));
+		$this->addGenerator(Normal::class, "normal", fn() => null);
+		$this->addGenerator(Normal::class, "default", fn() => null);
+		$this->addGenerator(Nether::class, "hell", fn() => null);
+		$this->addGenerator(Nether::class, "nether", fn() => null);
 	}
 
 	/**
-	 * @param string $class Fully qualified name of class that extends \pocketmine\world\generator\Generator
-	 * @param string $name Alias for this generator type that can be written in configs
-	 * @param bool   $overwrite Whether to force overwriting any existing registered generator with the same name
+	 * @param string                          $class Fully qualified name of class that extends \pocketmine\world\generator\Generator
+	 * @param string                          $name Alias for this generator type that can be written in configs
+	 * @param \Closure                        $presetValidator Callback to validate generator options for new worlds
+	 * @param bool                            $overwrite Whether to force overwriting any existing registered generator with the same name
+	 *
+	 * @phpstan-param \Closure(string) : ?InvalidGeneratorOptionsException $presetValidator
+	 *
 	 * @phpstan-param class-string<Generator> $class
 	 *
 	 * @throws \InvalidArgumentException
 	 */
-	public function addGenerator(string $class, string $name, bool $overwrite = false) : void{
+	public function addGenerator(string $class, string $name, \Closure $presetValidator, bool $overwrite = false) : void{
 		Utils::testValidInstance($class, Generator::class);
 
 		if(!$overwrite and isset($this->list[$name = strtolower($name)])){
 			throw new \InvalidArgumentException("Alias \"$name\" is already assigned");
 		}
 
-		$this->list[$name] = $class;
+		$this->list[$name] = new GeneratorManagerEntry($class, $presetValidator);
 	}
 
 	/**
@@ -75,12 +89,9 @@ final class GeneratorManager{
 	}
 
 	/**
-	 * Returns a class name of a registered Generator matching the given name.
-	 *
-	 * @return string|null Name of class that extends Generator, or null if no generator is mapped to that name
-	 * @phpstan-return class-string<Generator>|null
+	 * Returns the generator entry of a registered Generator matching the given name, or null if not found.
 	 */
-	public function getGenerator(string $name) : ?string{
+	public function getGenerator(string $name) : ?GeneratorManagerEntry{
 		return $this->list[strtolower($name)] ?? null;
 	}
 
@@ -95,7 +106,7 @@ final class GeneratorManager{
 	public function getGeneratorName(string $class) : string{
 		Utils::testValidInstance($class, Generator::class);
 		foreach($this->list as $name => $c){
-			if($c === $class){
+			if($c->getGeneratorClass() === $class){
 				return $name;
 			}
 		}

src/world/generator/GeneratorManagerEntry.php

@@ -0,0 +1,48 @@
+<?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\world\generator;
+
+final class GeneratorManagerEntry{
+
+	/**
+	 * @phpstan-param class-string<Generator> $generatorClass
+	 * @phpstan-param \Closure(string) : ?InvalidGeneratorOptionsException $presetValidator
+	 */
+	public function __construct(
+		private string $generatorClass,
+		private \Closure $presetValidator
+	){}
+
+	/** @phpstan-return class-string<Generator> */
+	public function getGeneratorClass() : string{ return $this->generatorClass; }
+
+	/**
+	 * @throws InvalidGeneratorOptionsException
+	 */
+	public function validateGeneratorOptions(string $generatorOptions) : void{
+		if(($exception = ($this->presetValidator)($generatorOptions)) !== null){
+			throw $exception;
+		}
+	}
+}