AssigneeValidationListener extension point

Listener to provide extensions with validation of assignees.

Change-Id: I61f6558d79b8e4c0d322c293dacdf4f33d882b26


* submodules:
* Update plugins/cookbook-plugin from branch 'master'
  - AssigneeValidator example
    
    Will not allow a user to be assigned to more than 5 changes.
    
    Change-Id: I1887f7007e66bd5ccac207c7789be2712ffbd00a

Documentation/config-validation.txt

@@ -80,6 +80,13 @@ input arguments.
 E.g. a plugin could use this to enforce a certain name scheme for
 group names.
 
+[[assignee-validation]]
+== Assignee validation
+
+
+Plugins implementing the `AssigneeValidationListener` interface can perform
+validation of assignees before they are assigned to a change.
+
 [[hashtag-validation]]
 == Hashtag validation
 

gerrit-server/src/main/java/com/google/gerrit/server/change/SetAssigneeOp.java

@@ -16,11 +16,13 @@ package com.google.gerrit.server.change;
 
 import com.google.common.base.Optional;
 import com.google.gerrit.extensions.api.changes.AssigneeInput;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
 import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.server.ChangeMessagesUtil;
 import com.google.gerrit.server.ChangeUtil;
@@ -31,6 +33,8 @@ import com.google.gerrit.server.config.AnonymousCowardName;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.notedb.ChangeUpdate;
 import com.google.gerrit.server.notedb.NotesMigration;
+import com.google.gerrit.server.validators.AssigneeValidationListener;
+import com.google.gerrit.server.validators.ValidationException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.assistedinject.Assisted;
 import com.google.inject.assistedinject.AssistedInject;
@@ -46,6 +50,9 @@ public class SetAssigneeOp extends BatchUpdate.Op {
   private final AccountInfoCacheFactory.Factory accountInfosFactory;
   private final NotesMigration notesMigration;
   private final String anonymousCowardName;
+  private final DynamicSet<AssigneeValidationListener> validationListeners;
+
+  private Change change;
   private Account newAssignee;
 
   @AssistedInject
@@ -54,13 +61,15 @@ public class SetAssigneeOp extends BatchUpdate.Op {
       ChangeMessagesUtil cmUtil,
       AccountInfoCacheFactory.Factory accountInfosFactory,
       @AnonymousCowardName String anonymousCowardName,
-      @Assisted AssigneeInput input) {
+      @Assisted AssigneeInput input,
+      DynamicSet<AssigneeValidationListener> validationListeners) {
     this.accounts = accounts;
     this.notesMigration = notesMigration;
     this.cmUtil = cmUtil;
     this.accountInfosFactory = accountInfosFactory;
     this.anonymousCowardName = anonymousCowardName;
     this.input = input;
+    this.validationListeners = validationListeners;
   }
 
   @Override
@@ -101,6 +110,13 @@ public class SetAssigneeOp extends BatchUpdate.Op {
           ctx.getChange().getChangeId(),
           newAssigneeUser.getUserName()));
     }
+    try {
+      for (AssigneeValidationListener validator : validationListeners) {
+        validator.validateAssignee(change, newAssigneeUser.getAccount());
+      }
+    } catch (ValidationException e) {
+      throw new BadRequestException(e.getMessage());
+    }
     update.setAssignee(newAssigneeUser.getAccountId());
     this.newAssignee = newAssigneeUser.getAccount();
     addMessage(ctx, update, oldAssignee);

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -162,6 +162,7 @@ import com.google.gerrit.server.ssh.SshAddressesModule;
 import com.google.gerrit.server.tools.ToolsCatalog;
 import com.google.gerrit.server.util.IdGenerator;
 import com.google.gerrit.server.util.ThreadLocalRequestContext;
+import com.google.gerrit.server.validators.AssigneeValidationListener;
 import com.google.gerrit.server.validators.GroupCreationValidationListener;
 import com.google.gerrit.server.validators.HashtagValidationListener;
 import com.google.gerrit.server.validators.OutgoingEmailValidationListener;
@@ -362,6 +363,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.setOf(binder(), AccountExternalIdCreator.class);
     DynamicSet.setOf(binder(), WebUiPlugin.class);
     DynamicItem.itemOf(binder(), AccountPatchReviewStore.class);
+    DynamicSet.setOf(binder(), AssigneeValidationListener.class);
 
     factory(UploadValidators.Factory.class);
     DynamicSet.setOf(binder(), UploadValidationListener.class);

gerrit-server/src/main/java/com/google/gerrit/server/validators/AssigneeValidationListener.java

@@ -0,0 +1,34 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.validators;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Change;
+
+/**
+ * Listener to provide validation of assignees.
+ */
+@ExtensionPoint
+public interface AssigneeValidationListener {
+  /**
+   * Invoked by Gerrit before the assignee of a change is modified.
+   *
+   * @param change the change on which the assignee is changed
+   * @param assignee the new assignee. Null if removed
+   * @throws ValidationException if validation fails
+   */
+  void validateAssignee(Change change, Account assignee) throws ValidationException;
+}