✨ Add injection services

CHANGELOG.md

@@ -10,6 +10,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Expose the Command which led to `InvalidCommandSenderException`s
  - Expose the CommandContext which led to `CommandExecutionException`s
  - Added helper methods for command flags to MutableCommandBuilder
+ - Added injection services
+ - Added a Guice injection service
+
+### Deprecated
+ - Deprecated ParameterInjectorRegistry#injectors
 
 ## [1.3.0] - 2020-12-18
 
@@ -27,6 +32,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Deprecated
  - String keyed command meta
+ - Deprecated ParameterInjectorRegistry#injectors
 
 ### Fixed
  - Fixed issue with task synchronization

buildSrc/src/main/kotlin/Versions.kt

@@ -4,6 +4,9 @@ object Versions {
     const val errorprone = "2.4.0"
     const val errorprone_javac = "9+181-r4173-1"
 
+    // INTEGRATION DEPENDENCIES
+    const val guice = "4.2.3"
+
     // DISCORD DEPENDENCIES
     const val javacord = "3.1.1"
     const val jda = "4.2.0_209"

cloud-annotations/src/main/java/cloud/commandframework/annotations/MethodCommandExecutionHandler.java

@@ -23,7 +23,6 @@
 //
 package cloud.commandframework.annotations;
 
-import cloud.commandframework.annotations.injection.ParameterInjector;
 import cloud.commandframework.annotations.injection.ParameterInjectorRegistry;
 import cloud.commandframework.arguments.CommandArgument;
 import cloud.commandframework.arguments.flags.FlagContext;
@@ -37,9 +36,9 @@
 import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 class MethodCommandExecutionHandler<C> implements CommandExecutionHandler<C> {
 
@@ -90,19 +89,13 @@ public void execute(final @NonNull CommandContext<C> commandContext) {
                 if (parameter.getType().isAssignableFrom(commandContext.getSender().getClass())) {
                     arguments.add(commandContext.getSender());
                 } else {
-                    final Collection<ParameterInjector<C, ?>> injectors = this.injectorRegistry.injectors(parameter.getType());
-                    Object value = null;
-                    for (final ParameterInjector<C, ?> injector : injectors) {
-                        value = injector.create(
-                                commandContext,
-                                this.annotationAccessor
-                        );
-                        if (value != null) {
-                            break;
-                        }
-                    }
-                    if (value != null) {
-                        arguments.add(value);
+                    final Optional<?> value = this.injectorRegistry.getInjectable(
+                            parameter.getType(),
+                            commandContext,
+                            this.annotationAccessor
+                    );
+                    if (value.isPresent()) {
+                        arguments.add(value.get());
                     } else {
                         throw new IllegalArgumentException(String.format(
                                 "Unknown command parameter '%s' in method '%s'",

cloud-core/build.gradle.kts

@@ -1,5 +1,6 @@
 dependencies {
     api(project(":cloud-services"))
+    implementation("com.google.inject", "guice", Versions.guice)
     testImplementation("org.openjdk.jmh", "jmh-core", Versions.jmh)
     testImplementation("org.openjdk.jmh", "jmh-generator-annprocess", Versions.jmh)
 }

cloud-core/src/main/java/cloud/commandframework/annotations/injection/GuiceInjectionService.java

@@ -0,0 +1,69 @@
+//
+// MIT License
+//
+// Copyright (c) 2020 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.annotations.injection;
+
+import cloud.commandframework.annotations.AnnotationAccessor;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.types.tuples.Triplet;
+import com.google.inject.ConfigurationException;
+import com.google.inject.Injector;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * {@link InjectionService Injection service} that injects using a Guice {@link Injector}
+ *
+ * @param <C> Command sender type
+ * @since 1.4.0
+ */
+public final class GuiceInjectionService<C> implements InjectionService<C> {
+
+    private final Injector injector;
+
+    private GuiceInjectionService(final @NonNull Injector injector) {
+        this.injector = injector;
+    }
+
+    /**
+     * Create a new Guice injection service that wraps the given injector
+     *
+     * @param injector Injector to wrap
+     * @param <C> Command sender type
+     * @return the created injection service
+     */
+    public static <C> GuiceInjectionService<C> create(final @NonNull Injector injector) {
+        return new GuiceInjectionService<>(injector);
+    }
+
+    @Override
+    @SuppressWarnings("EmptyCatch")
+    public @Nullable Object handle(final @NonNull Triplet<CommandContext<C>, Class<?>, AnnotationAccessor> triplet) {
+        try {
+            return this.injector.getInstance(triplet.getSecond());
+        } catch (final ConfigurationException ignored) {
+        }
+        return null;
+    }
+
+}

cloud-core/src/main/java/cloud/commandframework/annotations/injection/InjectionService.java

@@ -0,0 +1,43 @@
+//
+// MIT License
+//
+// Copyright (c) 2020 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.annotations.injection;
+
+import cloud.commandframework.annotations.AnnotationAccessor;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.services.types.Service;
+import cloud.commandframework.types.tuples.Triplet;
+
+/**
+ * Service that can be registered to the {@link ParameterInjectorRegistry} in order to provide
+ * custom injection support. This can be used to integrate the Cloud with existing dependency
+ * injection frameworks.
+ *
+ * @param <C> Command sender type
+ * @since 1.4.0
+ */
+@FunctionalInterface
+public interface InjectionService<C> extends
+        Service<Triplet<CommandContext<C>, Class<?>, AnnotationAccessor>, Object> {
+
+}

cloud-core/src/main/java/cloud/commandframework/annotations/injection/ParameterInjectorRegistry.java

@@ -23,7 +23,13 @@
 //
 package cloud.commandframework.annotations.injection;
 
+import cloud.commandframework.annotations.AnnotationAccessor;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.services.ServicePipeline;
+import cloud.commandframework.types.tuples.Triplet;
+import io.leangen.geantyref.TypeToken;
 import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -32,17 +38,28 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 /**
  * Registry containing mappings between {@link Class classes} and {@link ParameterInjector injectors}
  *
  * @param <C> Command sender type
  * @since 1.2.0
  */
-public final class ParameterInjectorRegistry<C> {
+@SuppressWarnings("ALL")
+public final class ParameterInjectorRegistry<C> implements InjectionService<C> {
 
     private volatile int injectorCount = 0;
     private final Map<Class<?>, List<ParameterInjector<C, ?>>> injectors = new HashMap<>();
+    private final ServicePipeline servicePipeline = ServicePipeline.builder().build();
+
+    /**
+     * Create a new parameter injector registry
+     */
+    public ParameterInjectorRegistry() {
+        servicePipeline.registerServiceType(new TypeToken<InjectionService<C>>() {
+        }, this);
+    }
 
     /**
      * Register an injector for a particular type
@@ -61,12 +78,16 @@ public synchronized <T> void registerInjector(
     }
 
     /**
-     * Get a collection of all injectors that could potentially inject a value of the given type
+     * Get a collection of all injectors that could potentially inject a value of the given type. This
+     * does not include injectors from external injector services, instead it only uses injectors
+     * registered using {@link #registerInjector(Class, ParameterInjector)}.
      *
      * @param clazz Type to query for
      * @param <T>   Generic type
      * @return Immutable collection containing all injectors that could potentially inject a value of the given type
+     * @deprecated Inject directly instead of relying on this list
      */
+    @Deprecated
     public synchronized <T> @NonNull Collection<@NonNull ParameterInjector<C, ?>> injectors(
             final @NonNull Class<T> clazz
     ) {
@@ -79,4 +100,55 @@ public synchronized <T> void registerInjector(
         return Collections.unmodifiableCollection(injectors);
     }
 
+    @Override
+    public @Nullable Object handle(final @NonNull Triplet<CommandContext<C>, Class<?>, AnnotationAccessor> triplet) {
+        for (final ParameterInjector<C, ?> injector : this.injectors(triplet.getSecond())) {
+            final Object value = injector.create(triplet.getFirst(), triplet.getThird());
+            if (value != null) {
+                return value;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Attempt to get an injectable value for the given context. This will consider all registered
+     * {@link InjectionService injection services}, and not just the {@link ParameterInjector injectors}
+     * registered using {@link #registerInjector(Class, ParameterInjector)}.
+     *
+     * @param clazz Class of the to inject
+     * @param context The command context that requests the injection
+     * @param annotationAccessor Annotation accessor for the injection. If the object is requested without access to annotations,
+     *                           use {@link AnnotationAccessor#empty()}
+     * @param <T> Type to inject
+     * @return The injected value, if an injector was able to provide a value
+     * @since 1.4.0
+     */
+    @SuppressWarnings("EmptyCatch")
+    public <@NonNull T> @NonNull Optional<T> getInjectable(
+            final @NonNull Class<T> clazz,
+            final @NonNull CommandContext<C> context,
+            final @NonNull AnnotationAccessor annotationAccessor
+    ) {
+        final Triplet<CommandContext<C>, Class<?>, AnnotationAccessor> triplet = Triplet.of(context, clazz, annotationAccessor);
+        try {
+            return Optional.of(clazz.cast(this.servicePipeline.pump(triplet).through(new TypeToken<InjectionService<C>>() {
+            }).getResult()));
+        } catch (final IllegalStateException ignored) {
+        }
+        return Optional.empty();
+    }
+
+    /**
+     * Register an injection service that will be able to provide injections using
+     * {@link #getInjectable(Class, CommandContext, AnnotationAccessor)}.
+     *
+     * @param service Service implementation
+     * @since 1.4.0
+     */
+    public void registerInjectionService(final InjectionService<C> service) {
+        this.servicePipeline.registerServiceImplementation(new TypeToken<InjectionService<C>>() {
+        }, service, Collections.emptyList());
+    }
+
 }

cloud-core/src/main/java/cloud/commandframework/context/CommandContext.java

@@ -25,7 +25,6 @@
 
 import cloud.commandframework.CommandManager;
 import cloud.commandframework.annotations.AnnotationAccessor;
-import cloud.commandframework.annotations.injection.ParameterInjector;
 import cloud.commandframework.arguments.CommandArgument;
 import cloud.commandframework.arguments.flags.FlagContext;
 import cloud.commandframework.captions.Caption;
@@ -603,13 +602,7 @@ public void setCurrentArgument(final @Nullable CommandArgument<C, ?> argument) {
                     "Cannot retrieve injectable values from a command context that is not associated with a command manager"
             );
         }
-        for (final ParameterInjector<C, ?> injector : this.commandManager.parameterInjectorRegistry().injectors(clazz)) {
-            final Object value = injector.create(this, AnnotationAccessor.empty());
-            if (value != null) {
-                return Optional.of((T) value);
-            }
-        }
-        return Optional.empty();
+        return this.commandManager.parameterInjectorRegistry().getInjectable(clazz, this, AnnotationAccessor.empty());
     }