[WIP] Add dependency injection functionality, Closes #85 (#86)

MiniDigger · aikar · commit cebe28ef6c3f · 2018-01-25T14:21:16.000-05:00
* misc improvements (as suggested by intellij) * first draft of the DI functionality (#85) * address review * reenabled disabled inspections * overload registerDependency method * inject fields of superclasses two and remove invalid sponge default dependency
diff --git a/bukkit/src/main/java/co/aikar/commands/BukkitCommandCompletions.java b/bukkit/src/main/java/co/aikar/commands/BukkitCommandCompletions.java
@@ -74,7 +74,7 @@ public BukkitCommandCompletions(BukkitCommandManager manager) {
 
             Player senderPlayer = sender instanceof Player ? (Player) sender : null;
 
-            ArrayList<String> matchedPlayers = new ArrayList<String>();
+            ArrayList<String> matchedPlayers = new ArrayList<>();
             for (Player player : Bukkit.getOnlinePlayers()) {
                 String name = player.getName();
                 if ((senderPlayer == null || senderPlayer.canSee(player)) && StringUtil.startsWithIgnoreCase(name, c.getInput())) {
diff --git a/bukkit/src/main/java/co/aikar/commands/BukkitCommandManager.java b/bukkit/src/main/java/co/aikar/commands/BukkitCommandManager.java
@@ -35,8 +35,13 @@
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.SimpleCommandMap;
 import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemFactory;
 import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginManager;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.bukkit.scheduler.BukkitScheduler;
 import org.bukkit.scheduler.BukkitTask;
+import org.bukkit.scoreboard.ScoreboardManager;
 import org.jetbrains.annotations.NotNull;
 
 import java.lang.reflect.Field;
@@ -95,6 +100,15 @@ public BukkitCommandManager(Plugin plugin) {
             }
             Bukkit.getOnlinePlayers().forEach(this::readPlayerLocale);
         }, 5, 5);
+
+        registerDependency(plugin.getClass(), plugin);
+        registerDependency(Plugin.class, plugin);
+        registerDependency(JavaPlugin.class, plugin);
+        registerDependency(PluginManager.class, Bukkit.getPluginManager());
+        registerDependency(Server.class, Bukkit.getServer());
+        registerDependency(BukkitScheduler.class, Bukkit.getScheduler());
+        registerDependency(ScoreboardManager.class, Bukkit.getScoreboardManager());
+        registerDependency(ItemFactory.class, Bukkit.getItemFactory());
     }
 
     @NotNull private CommandMap hookCommandMap() {
@@ -261,7 +275,7 @@ void readPlayerLocale(Player player) {
             if (nmsPlayer != null) {
                 Field localeField = nmsPlayer.getClass().getField("locale");
                 Object localeString = localeField.get(nmsPlayer);
-                if (localeString != null && localeString instanceof String) {
+                if (localeString instanceof String) {
                     String[] split = ACFPatterns.UNDERSCORE.split((String) localeString);
                     Locale locale = split.length > 1 ? new Locale(split[0], split[1]) : new Locale(split[0]);
                     Locale prev = issuersLocale.put(player.getUniqueId(), locale);
diff --git a/bukkit/src/main/java/co/aikar/commands/ProxyCommandMap.java b/bukkit/src/main/java/co/aikar/commands/ProxyCommandMap.java
@@ -87,7 +87,7 @@ public boolean dispatch(CommandSender sender, String cmdLine) throws CommandExce
 
     @Override
     public void clearCommands() {
-        super.clearCommands();;
+        super.clearCommands();
         proxied.clearCommands();
     }
 
diff --git a/bungee/src/main/java/co/aikar/commands/ACFBungeeUtil.java b/bungee/src/main/java/co/aikar/commands/ACFBungeeUtil.java
@@ -79,7 +79,7 @@ public static String replaceChatString(String message, Pattern replace, String w
     public static final char COLOR_CHAR = '\u00A7';
 
     public static String getLastColors(String input) {
-        String result = "";
+        StringBuilder result = new StringBuilder();
         int length = input.length();
 
         // Search backwards from the end as it is faster
@@ -90,7 +90,7 @@ public static String getLastColors(String input) {
                 ChatColor color = ChatColor.getByChar(c);
 
                 if (color != null) {
-                    result = color.toString() + result;
+                    result.insert(0, color.toString());
 
                     // Once we find a color or reset we can stop searching
                     if (isChatColorAColor(color) || color.equals(ChatColor.RESET)) {
@@ -99,7 +99,7 @@ public static String getLastColors(String input) {
                 }
             }
         }
-        return result;
+        return result.toString();
     }
 
     public static boolean isChatColorAColor(ChatColor chatColor) {
diff --git a/bungee/src/main/java/co/aikar/commands/BungeeCommandManager.java b/bungee/src/main/java/co/aikar/commands/BungeeCommandManager.java
@@ -58,6 +58,10 @@ public BungeeCommandManager(Plugin plugin) {
         this.formatters.put(MessageType.INFO, new BungeeMessageFormatter(ChatColor.BLUE, ChatColor.DARK_GREEN, ChatColor.GREEN));
         this.formatters.put(MessageType.HELP, new BungeeMessageFormatter(ChatColor.AQUA, ChatColor.GREEN, ChatColor.YELLOW));
         getLocales(); // auto load locales
+
+        // TODO more default dependencies for bungee
+        registerDependency(plugin.getClass(), plugin);
+        registerDependency(Plugin.class, plugin);
     }
 
     public Plugin getPlugin() {
diff --git a/core/src/main/java/co/aikar/commands/BaseCommand.java b/core/src/main/java/co/aikar/commands/BaseCommand.java
@@ -123,6 +123,7 @@ void onRegister(CommandManager manager) {
         onRegister(manager, this.commandName);
     }
     void onRegister(CommandManager manager, String cmd) {
+        manager.injectDependencies(this);
         this.manager = manager;
         final Class<? extends BaseCommand> self = this.getClass();
         CommandAlias rootCmdAliasAnno = self.getAnnotation(CommandAlias.class);
diff --git a/core/src/main/java/co/aikar/commands/CommandManager.java b/core/src/main/java/co/aikar/commands/CommandManager.java
@@ -23,15 +23,19 @@
 
 package co.aikar.commands;
 
-import co.aikar.commands.annotation.Conditions;
+import co.aikar.commands.annotation.Dependency;
 import co.aikar.locales.MessageKeyProvider;
+import com.google.common.collect.HashBasedTable;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
+import com.google.common.collect.Table;
 import org.jetbrains.annotations.NotNull;
 
+import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
 import java.util.List;
@@ -53,18 +57,17 @@ public abstract class CommandManager <
     /**
      * This is a stack incase a command calls a command
      */
-    static ThreadLocal<Stack<CommandOperationContext>> commandOperationContext = ThreadLocal.withInitial(() -> {
-        return new Stack<CommandOperationContext>() {
-            @Override
-            public synchronized CommandOperationContext peek() {
-                return super.size() == 0 ? null : super.peek();
-            }
-        };
+    static ThreadLocal<Stack<CommandOperationContext>> commandOperationContext = ThreadLocal.withInitial(() -> new Stack<CommandOperationContext>() {
+        @Override
+        public synchronized CommandOperationContext peek() {
+            return super.size() == 0 ? null : super.peek();
+        }
     });
     protected Map<String, RootCommand> rootCommands = new HashMap<>();
     protected final CommandReplacements replacements = new CommandReplacements(this);
     protected final CommandConditions<I, CEC, CC> conditions = new CommandConditions<>(this);
     protected ExceptionHandler defaultExceptionHandler = null;
+    protected Table<Class<?>, String, Object> dependencies = HashBasedTable.create();
 
     protected boolean usePerIssuerLocale = false;
     protected List<IssuerLocaleChangedCallback<I>> localeChangedCallbacks = Lists.newArrayList();
@@ -377,6 +380,73 @@ public void addSupportedLanguage(Locale locale) {
         getLocales().loadMissingBundles();
     }
 
+    /**
+     * Registers an instance of a class to be registered as an injectable dependency.<br>
+     * The command manager will attempt to inject all fields in a command class that are annotated with
+     * {@link co.aikar.commands.annotation.Dependency} with the provided instance.
+     *
+     * @param clazz the class the injector should look for when injecting
+     * @param instance the instance of the class that should be injected
+     * @throws IllegalStateException when there is already an instance for the provided class registered
+     */
+    public <T> void registerDependency(Class<? extends T> clazz, T instance){
+        registerDependency(clazz, clazz.getName(), instance);
+    }
+
+    /**
+     * Registers an instance of a class to be registered as an injectable dependency.<br>
+     * The command manager will attempt to inject all fields in a command class that are annotated with
+     * {@link co.aikar.commands.annotation.Dependency} with the provided instance.
+     *
+     * @param clazz the class the injector should look for when injecting
+     * @param key the key which needs to be present if that
+     * @param instance the instance of the class that should be injected
+     * @throws IllegalStateException when there is already an instance for the provided class registered
+     */
+    public <T> void registerDependency(Class<? extends T> clazz, String key, T instance){
+        if(dependencies.containsRow(clazz) && dependencies.containsColumn(key)){
+            throw new IllegalStateException("There is already an instance of " + clazz.getName() + " with the key " + key + " registered!");
+        }
+
+        dependencies.put(clazz, key, instance);
+    }
+
+    /**
+     * Attempts to inject instances of classes registered with {@link CommandManager#registerDependency(Class, Object)}
+     * into all fields of the class and its superclasses that are marked with {@link Dependency}.
+     *
+     * @param baseCommand the instance which fields should be filled
+     */
+    void injectDependencies(BaseCommand baseCommand) {
+        Class clazz = baseCommand.getClass();
+        do {
+            for (Field field : clazz.getDeclaredFields()) {
+                if (field.isAnnotationPresent(Dependency.class)) {
+                    Dependency dependency = field.getAnnotation(Dependency.class);
+                    String key = (key = dependency.value()).equals("") ? field.getType().getName() : key;
+                    Object object = dependencies.row(field.getType()).get(key);
+                    if (object == null) {
+                        throw new UnresolvedDependencyException("Could not find a registered instance of " +
+                                field.getType().getName() + " with key " + key + " for field " + field.getName() +
+                                " in class " + baseCommand.getClass().getName());
+                    }
+
+                    try {
+                        boolean accessible = field.isAccessible();
+                        if (!accessible) {
+                            field.setAccessible(true);
+                        }
+                        field.set(baseCommand, object);
+                        field.setAccessible(accessible);
+                    } catch (IllegalAccessException e) {
+                        e.printStackTrace(); //TODO should we print our own exception here to make a more descriptive error?
+                    }
+                }
+            }
+            clazz = clazz.getSuperclass();
+        } while (!clazz.equals(BaseCommand.class));
+    }
+
     /**
      * @deprecated Use this with caution! If you enable and use Unstable API's, your next compile using ACF
      * may require you to update your implementation to those unstable API's
diff --git a/core/src/main/java/co/aikar/commands/InvalidCommandArgument.java b/core/src/main/java/co/aikar/commands/InvalidCommandArgument.java
@@ -32,7 +32,7 @@ public class InvalidCommandArgument extends Exception {
     final String[] replacements;
 
     public InvalidCommandArgument() {
-        this((String) null, true);
+        this(null, true);
     }
     public InvalidCommandArgument(boolean showSyntax) {
         this(null, showSyntax);
diff --git a/core/src/main/java/co/aikar/commands/UnresolvedDependencyException.java b/core/src/main/java/co/aikar/commands/UnresolvedDependencyException.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016-2018 Daniel Ennis (Aikar) - MIT License
+ *
+ *  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 co.aikar.commands;
+
+/**
+ * Thrown when a command mananger couldn't find a registered instance for a field that is marked with
+ * {@link co.aikar.commands.annotation.Dependency}
+ */
+public class UnresolvedDependencyException extends RuntimeException {
+    UnresolvedDependencyException(String message) {
+        super(message);
+    }
+}
diff --git a/core/src/main/java/co/aikar/commands/annotation/Dependency.java b/core/src/main/java/co/aikar/commands/annotation/Dependency.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2016-2018 Daniel Ennis (Aikar) - MIT License
+ *
+ *  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 co.aikar.commands.annotation;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Dependency {
+    /**
+     * The key that should be used to lookup the instances, defaults to \"\"
+     * @return the key
+     */
+    String value() default "";
+}
diff --git a/example/src/main/java/co/aikar/acfexample/ACFExample.java b/example/src/main/java/co/aikar/acfexample/ACFExample.java
@@ -78,17 +78,27 @@ private void registerCommands() {
             }
         });
 
-        // 6: Register your commands - This first command demonstrates adding an exception handler to that command
+        // 6: (Optionally) Register dependencies - Dependencies can be injected into fields of command classes by
+        // marking them with @Dependency. Some classes, like your Plugin, are already registered by default.
+        SomeHandler someHandler = new SomeHandler();
+        someHandler.setSomeField("Secret");
+        commandManager.registerDependency(SomeHandler.class, someHandler);
+        commandManager.registerDependency(String.class, "Test3");
+        commandManager.registerDependency(String.class, "test", "Test");
+        commandManager.registerDependency(String.class, "test2", "Test2");
+
+        // 7: Register your commands - This first command demonstrates adding an exception handler to that command
         commandManager.registerCommand(new SomeCommand().setExceptionHandler((command, registeredCommand, sender, args, t) -> {
                 sender.sendMessage(MessageType.ERROR, MessageKeys.ERROR_GENERIC_LOGGED);
                 return true; // mark as handeled, default message will not be send to sender
         }));
-        // 7: Register an additional command. This one happens to share the same CommandAlias as the previous command
+
+        // 8: Register an additional command. This one happens to share the same CommandAlias as the previous command
         // This means it simply registers additional sub commands under the same command, but organized into separate
         // Classes (Maybe different permission sets)
         commandManager.registerCommand(new SomeCommand_ExtraSubs());
 
-        // 8: Register default exception handler for any command that doesn't supply its own
+        // 9: Register default exception handler for any command that doesn't supply its own
         commandManager.setDefaultExceptionHandler((command, registeredCommand, sender, args, t) -> {
             getLogger().warning("Error occured while executing command " + command.getName());
             return false; // mark as unhandeled, sender will see default message
diff --git a/example/src/main/java/co/aikar/acfexample/SomeCommand.java b/example/src/main/java/co/aikar/acfexample/SomeCommand.java
@@ -29,13 +29,15 @@
 import co.aikar.commands.annotation.CommandPermission;
 import co.aikar.commands.annotation.Conditions;
 import co.aikar.commands.annotation.Default;
+import co.aikar.commands.annotation.Dependency;
 import co.aikar.commands.annotation.Optional;
 import co.aikar.commands.annotation.Subcommand;
 import co.aikar.commands.annotation.Values;
 import co.aikar.commands.contexts.OnlinePlayer;
 import org.bukkit.World;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
 
 @CommandAlias("acf|somecommand|sc|somcom")
 public class SomeCommand extends BaseCommand {
@@ -46,6 +48,29 @@ public class SomeCommand extends BaseCommand {
         setContextFlags(SomeObject.class, "foo=bar");
     }
 
+    // marking fields with @Dependency allows you to define  instances that should be easily accessible to commands
+    @Dependency
+    private SomeHandler someHandler;
+    // some classes like your plugin are automatically registered for injection
+    @Dependency
+    private Plugin plugin;
+    // you can even use named injections to have multiple instances of the same type
+    @Dependency("test")
+    private String testString;
+    @Dependency("test2")
+    private String testString2;
+    @Dependency
+    private String testString3;
+
+    @Subcommand("testDI")
+    public void onTestDI(CommandSender sender){
+        sender.sendMessage("The value for the injected SomeHandler is " + someHandler.getSomeField());
+        sender.sendMessage("Plugin is null? " + (plugin == null));
+        sender.sendMessage("Test String 1: " + testString);
+        sender.sendMessage("Test String 2: " + testString2);
+        sender.sendMessage("Test String 3: " + testString3);
+    }
+
     // %testcmd was defined in ACFExample plugin and defined as "test4|foobar|barbaz"
     // This means, /test4, /foobar and /barbaz all are aliased here.
     // functionally equivalent to @CommandAlias("test4|foobar|barbaz") but could be dynamic (Read from config)
diff --git a/example/src/main/java/co/aikar/acfexample/SomeHandler.java b/example/src/main/java/co/aikar/acfexample/SomeHandler.java
@@ -0,0 +1,14 @@
+package co.aikar.acfexample;
+
+public class SomeHandler {
+
+    private String someField;
+
+    public String getSomeField() {
+        return someField;
+    }
+
+    public void setSomeField(String someField) {
+        this.someField = someField;
+    }
+}
diff --git a/sponge/src/main/java/co/aikar/commands/ACFSpongeUtil.java b/sponge/src/main/java/co/aikar/commands/ACFSpongeUtil.java
diff --git a/sponge/src/main/java/co/aikar/commands/SpongeCommandContexts.java b/sponge/src/main/java/co/aikar/commands/SpongeCommandContexts.java
diff --git a/sponge/src/main/java/co/aikar/commands/SpongeCommandManager.java b/sponge/src/main/java/co/aikar/commands/SpongeCommandManager.java

Original file line number	Diff line number	Diff line change
`@@ -87,7 +87,7 @@ public boolean dispatch(CommandSender sender, String cmdLine) throws CommandExce`
`87`	`87`
`88`	`88`	`@Override`
`89`	`89`	`public void clearCommands() {`
`90`		`- super.clearCommands();;`
	`90`	`+ super.clearCommands();`
`91`	`91`	`proxied.clearCommands();`
`92`	`92`	`}`
`93`	`93`
Original file line number	Diff line number	Diff line change
`@@ -79,7 +79,7 @@ public static String replaceChatString(String message, Pattern replace, String w`
`79`	`79`	`public static final char COLOR_CHAR = '\u00A7';`
`80`	`80`
`81`	`81`	`public static String getLastColors(String input) {`
`82`		`- String result = "";`
	`82`	`+ StringBuilder result = new StringBuilder();`
`83`	`83`	`int length = input.length();`
`84`	`84`
`85`	`85`	`// Search backwards from the end as it is faster`
`@@ -90,7 +90,7 @@ public static String getLastColors(String input) {`
`90`	`90`	`ChatColor color = ChatColor.getByChar(c);`
`91`	`91`
`92`	`92`	`if (color != null) {`
`93`		`- result = color.toString() + result;`
	`93`	`+ result.insert(0, color.toString());`
`94`	`94`
`95`	`95`	`// Once we find a color or reset we can stop searching`
`96`	`96`	`if (isChatColorAColor(color) \|\| color.equals(ChatColor.RESET)) {`
`@@ -99,7 +99,7 @@ public static String getLastColors(String input) {`
`99`	`99`	`}`
`100`	`100`	`}`
`101`	`101`	`}`
`102`		`- return result;`
	`102`	`+ return result.toString();`
`103`	`103`	`}`
`104`	`104`
`105`	`105`	`public static boolean isChatColorAColor(ChatColor chatColor) {`
Original file line number	Diff line number	Diff line change
`@@ -123,6 +123,7 @@ void onRegister(CommandManager manager) {`
`123`	`123`	`onRegister(manager, this.commandName);`
`124`	`124`	`}`
`125`	`125`	`void onRegister(CommandManager manager, String cmd) {`
	`126`	`+ manager.injectDependencies(this);`
`126`	`127`	`this.manager = manager;`
`127`	`128`	`final Class<? extends BaseCommand> self = this.getClass();`
`128`	`129`	`CommandAlias rootCmdAliasAnno = self.getAnnotation(CommandAlias.class);`
Original file line number	Diff line number	Diff line change
`@@ -32,7 +32,7 @@ public class InvalidCommandArgument extends Exception {`
`32`	`32`	`final String[] replacements;`
`33`	`33`
`34`	`34`	`public InvalidCommandArgument() {`
`35`		`- this((String) null, true);`
	`35`	`+ this(null, true);`
`36`	`36`	`}`
`37`	`37`	`public InvalidCommandArgument(boolean showSyntax) {`
`38`	`38`	`this(null, showSyntax);`