feature: introduce CommandFactory

Alexander Söderberg · Alexander Söderberg · commit 4cc54f0fe927 · 2023-11-12T19:04:30.000+01:00
diff --git a/cloud-core/src/main/java/cloud/commandframework/CommandBean.java b/cloud-core/src/main/java/cloud/commandframework/CommandBean.java
@@ -26,6 +26,8 @@
 import cloud.commandframework.context.CommandContext;
 import cloud.commandframework.execution.CommandExecutionHandler;
 import cloud.commandframework.meta.CommandMeta;
+import java.util.Collections;
+import java.util.List;
 import org.apiguardian.api.API;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
@@ -37,14 +39,15 @@
  * to implement your command handler. You may also provide custom handler when {@link #configure(Command.Builder)} is invoked.
  * <p>
  * Information about the command, such as aliases, should be provided by {@link #properties()}. The command bean may be
- * registered to the command manager by using {@link CommandManager#command(CommandBean)}. This will invoke {@link #configure(Command.Builder)}
+ * registered to the command manager by using {@link CommandManager#command(CommandFactory)}. This will invoke
+ * {@link #configure(Command.Builder)}
  * where you may configure the command. The command meta may be configured by overriding {@link #meta()}.
  *
  * @param <C> the command sender type
  * @since 2.0.0
  */
 @API(status = API.Status.STABLE, since = "2.0.0")
-public abstract class CommandBean<C> implements CommandExecutionHandler<C> {
+public abstract class CommandBean<C> implements CommandExecutionHandler<C>, CommandFactory<C> {
 
     protected CommandBean() {
     }
@@ -57,14 +60,15 @@ protected CommandBean() {
      * @param commandManager the command manager
      * @return the constructed command
      */
-    public @NonNull Command<C> constructCommand(final @NonNull CommandManager<C> commandManager) {
+    @Override
+    public @NonNull List<@NonNull Command<C>> createCommand(final @NonNull CommandManager<C> commandManager) {
         final Command.Builder<C> builder = commandManager.commandBuilder(
                 this.properties().name(),
                 this.properties().aliases(),
                 this.meta()
         ).handler(this);
         this.configure(builder);
-        return builder.build();
+        return Collections.singletonList(builder.build());
     }
 
     /**
diff --git a/cloud-core/src/main/java/cloud/commandframework/CommandFactory.java b/cloud-core/src/main/java/cloud/commandframework/CommandFactory.java
@@ -0,0 +1,49 @@
+//
+// MIT License
+//
+// Copyright (c) 2022 Alexander Söderberg & Contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+package cloud.commandframework;
+
+import java.util.List;
+import org.apiguardian.api.API;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * Factory producing command instances
+ *
+ * @param <C> the command sender type
+ */
+@API(status = API.Status.STABLE, since = "2.0.0")
+@FunctionalInterface
+public interface CommandFactory<C> {
+
+    /**
+     * Creates commands using the given {@code commandManager}. Each invocation produces unique instances of the commands.
+     * <p>
+     * This method has no side effects, meaning that the created commands will not be automatically registered to the
+     * {@link CommandManager command manager}.
+     *
+     * @param commandManager the command manager
+     * @return the created commands
+     */
+    @NonNull List<@NonNull Command<C>> createCommand(@NonNull CommandManager<C> commandManager);
+}
diff --git a/cloud-core/src/main/java/cloud/commandframework/CommandManager.java b/cloud-core/src/main/java/cloud/commandframework/CommandManager.java
@@ -246,21 +246,23 @@ protected CommandManager(
     }
 
     /**
-     * Register a new command to the command manager and insert it into the underlying command tree. The command will be
-     * forwarded to the {@link CommandRegistrationHandler} and will, depending on the platform, be forwarded to the platform.
+     * Creates a command using the given {@code commandFactory} and inserts it into the underlying command tree. The command
+     * will be forwarded to the {@link CommandRegistrationHandler} and will, depending on the platform, be forwarded to the
+     * platform.
      * <p>
      * Different command manager implementations have different requirements for the command registration. It is possible
      * that a command manager may only allow registration during certain stages of the application lifetime. Read the platform
      * command manager documentation to find out more about your particular platform
      *
-     * @param commandBean the command bean to register
+     * @param commandFactory the command factory to register
      * @return The command manager instance. This is returned so that these method calls may be chained. This will always
      *         return {@code this}
      * @since 2.0.0
      */
     @API(status = API.Status.STABLE, since = "2.0.0")
-    public @NonNull @This CommandManager<C> command(final @NonNull CommandBean<C> commandBean) {
-        return this.command(commandBean.constructCommand(this));
+    public @NonNull @This CommandManager<C> command(final @NonNull CommandFactory<C> commandFactory) {
+        commandFactory.createCommand(this).forEach(this::command);
+        return this;
     }
 
     /**
