Merge pull request #1615 from gitbucket/feature/plugin-notification

Add hook for issue and pull request

doc/notification.md

@@ -17,6 +17,7 @@ When the ```CLOSED``` column value is updated, GitBucket does the notification.
 Notified users are as follows:
 
 * individual repository's owner
+* group members of group repository
 * collaborators
 * participants
 

src/main/scala/gitbucket/core/controller/AccountController.scala

@@ -206,9 +206,13 @@ trait AccountControllerBase extends AccountManagementControllerBase {
 //        FileUtils.deleteDirectory(getWikiRepositoryDir(userName, repositoryName))
 //        FileUtils.deleteDirectory(getTemporaryDir(userName, repositoryName))
 //      }
-//      // Remove from GROUP_MEMBER, COLLABORATOR and REPOSITORY
+        // Remove from GROUP_MEMBER and COLLABORATOR
         removeUserRelatedData(userName)
         updateAccount(account.copy(isRemoved = true))
+
+        // call hooks
+        PluginRegistry().getAccountHooks.foreach(_.deleted(userName))
+
         session.invalidate
         redirect("/")
       }

src/main/scala/gitbucket/core/controller/PullRequestsController.scala

@@ -1,6 +1,7 @@
 package gitbucket.core.controller
 
 import gitbucket.core.model.WebHook
+import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.pulls.html
 import gitbucket.core.service.CommitStatusService
 import gitbucket.core.service.MergeService
@@ -277,10 +278,8 @@ trait PullRequestsControllerBase extends ControllerBase {
             // call web hook
             callPullRequestWebHook("closed", repository, issueId, context.baseUrl, context.loginAccount.get)
 
-            // notifications
-            Notifier().toNotify(repository, issue, "merge"){
-              Notifier.msgStatus(s"${context.baseUrl}/${owner}/${name}/pull/${issueId}")
-            }
+            // call hooks
+            PluginRegistry().getPullRequestHooks.foreach(_.merged(issue, repository))
 
             redirect(s"/${owner}/${name}/pull/${issueId}")
           }
@@ -484,10 +483,8 @@ trait PullRequestsControllerBase extends ControllerBase {
         // extract references and create refer comment
         createReferComment(owner, name, issue, form.title + " " + form.content.getOrElse(""), context.loginAccount.get)
 
-        // notifications
-        Notifier().toNotify(repository, issue, form.content.getOrElse("")) {
-          Notifier.msgPullRequest(s"${context.baseUrl}/${owner}/${name}/pull/${issueId}")
-        }
+        // call hooks
+        PluginRegistry().getPullRequestHooks.foreach(_.created(issue, repository))
       }
 
       redirect(s"/${owner}/${name}/pull/${issueId}")

src/main/scala/gitbucket/core/controller/SystemSettingsController.scala

@@ -225,7 +225,7 @@ trait SystemSettingsControllerBase extends AccountManagementControllerBase {
           //          FileUtils.deleteDirectory(getWikiRepositoryDir(userName, repositoryName))
           //          FileUtils.deleteDirectory(getTemporaryDir(userName, repositoryName))
           //        }
-          // Remove from GROUP_MEMBER, COLLABORATOR and REPOSITORY
+          // Remove from GROUP_MEMBER and COLLABORATOR
           removeUserRelatedData(userName)
         }
 
@@ -239,6 +239,10 @@ trait SystemSettingsControllerBase extends AccountManagementControllerBase {
           isRemoved    = form.isRemoved))
 
         updateImage(userName, form.fileId, form.clearImage)
+
+        // call hooks
+        if(form.isRemoved) PluginRegistry().getAccountHooks.foreach(_.deleted(userName))
+
         redirect("/admin/users")
       }
     } getOrElse NotFound()

src/main/scala/gitbucket/core/plugin/AccountHook.scala

@@ -0,0 +1,10 @@
+package gitbucket.core.plugin
+
+import gitbucket.core.model.Profile._
+import profile.api._
+
+trait AccountHook {
+
+  def deleted(userName: String)(implicit session: Session): Unit = ()
+
+}

src/main/scala/gitbucket/core/plugin/IssueHook.scala

@@ -0,0 +1,20 @@
+package gitbucket.core.plugin
+
+import gitbucket.core.controller.Context
+import gitbucket.core.model.Issue
+import gitbucket.core.service.RepositoryService.RepositoryInfo
+
+trait IssueHook {
+
+  def created(issue: Issue, repository: RepositoryInfo)(implicit context: Context): Unit = ()
+  def addedComment(commentId: Int, content: String, issue: Issue, repository: RepositoryInfo)(implicit context: Context): Unit = ()
+  def closed(issue: Issue, repository: RepositoryInfo)(implicit context: Context): Unit = ()
+  def reopened(issue: Issue, repository: RepositoryInfo)(implicit context: Context): Unit = ()
+
+}
+
+trait PullRequestHook extends IssueHook {
+
+  def merged(issue: Issue, repository: RepositoryInfo)(implicit context: Context): Unit = ()
+
+}

src/main/scala/gitbucket/core/plugin/Plugin.scala

@@ -1,12 +1,14 @@
 package gitbucket.core.plugin
 
 import javax.servlet.ServletContext
+
 import gitbucket.core.controller.{Context, ControllerBase}
-import gitbucket.core.model.Account
+import gitbucket.core.model.{Account, Issue}
 import gitbucket.core.service.RepositoryService.RepositoryInfo
 import gitbucket.core.service.SystemSettingsService.SystemSettings
 import gitbucket.core.util.SyntaxSugars._
 import io.github.gitbucket.solidbase.model.Version
+import play.twirl.api.Html
 
 /**
  * Trait for define plugin interface.
@@ -69,6 +71,16 @@ abstract class Plugin {
    */
   def repositoryRoutings(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[GitRepositoryRouting] = Nil
 
+  /**
+   * Override to add account hooks.
+   */
+  val accountHooks: Seq[AccountHook] = Nil
+
+  /**
+   * Override to add account hooks.
+   */
+  def accountHooks(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[AccountHook] = Nil
+
   /**
    * Override to add receive hooks.
    */
@@ -89,6 +101,26 @@ abstract class Plugin {
    */
   def repositoryHooks(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[RepositoryHook] = Nil
 
+  /**
+   * Override to add issue hooks.
+   */
+  val issueHooks: Seq[IssueHook] = Nil
+
+  /**
+   * Override to add issue hooks.
+   */
+  def issueHooks(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[IssueHook] = Nil
+
+  /**
+   * Override to add pull request hooks.
+   */
+  val pullRequestHooks: Seq[PullRequestHook] = Nil
+
+  /**
+   * Override to add pull request hooks.
+   */
+  def pullRequestHooks(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[PullRequestHook] = Nil
+
   /**
    * Override to add global menus.
    */
@@ -159,6 +191,16 @@ abstract class Plugin {
    */
   def dashboardTabs(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[(Context) => Option[Link]] = Nil
 
+  /**
+   * Override to add issue sidebars.
+   */
+  val issueSidebars: Seq[(Issue, RepositoryInfo, Context) => Option[Html]] = Nil
+
+  /**
+   * Override to add issue sidebars.
+   */
+  def issueSidebars(registry: PluginRegistry, context: ServletContext, settings: SystemSettings): Seq[(Issue, RepositoryInfo, Context) => Option[Html]] = Nil
+
   /**
    * Override to add assets mappings.
    */
@@ -209,12 +251,21 @@ abstract class Plugin {
     (repositoryRoutings ++ repositoryRoutings(registry, context, settings)).foreach { routing =>
       registry.addRepositoryRouting(routing)
     }
+    (accountHooks ++ accountHooks(registry, context, settings)).foreach { accountHook =>
+      registry.addAccountHook(accountHook)
+    }
     (receiveHooks ++ receiveHooks(registry, context, settings)).foreach { receiveHook =>
       registry.addReceiveHook(receiveHook)
     }
     (repositoryHooks ++ repositoryHooks(registry, context, settings)).foreach { repositoryHook =>
       registry.addRepositoryHook(repositoryHook)
     }
+    (issueHooks ++ issueHooks(registry, context, settings)).foreach { issueHook =>
+      registry.addIssueHook(issueHook)
+    }
+    (pullRequestHooks ++ pullRequestHooks(registry, context, settings)).foreach { pullRequestHook =>
+      registry.addPullRequestHook(pullRequestHook)
+    }
     (globalMenus ++ globalMenus(registry, context, settings)).foreach { globalMenu =>
       registry.addGlobalMenu(globalMenu)
     }
@@ -236,6 +287,9 @@ abstract class Plugin {
     (dashboardTabs ++ dashboardTabs(registry, context, settings)).foreach { dashboardTab =>
       registry.addDashboardTab(dashboardTab)
     }
+    (issueSidebars ++ issueSidebars(registry, context, settings)).foreach { issueSidebar =>
+      registry.addIssueSidebar(issueSidebar)
+    }
     (assetsMappings ++ assetsMappings(registry, context, settings)).foreach { assetMapping =>
       registry.addAssetsMapping((assetMapping._1, assetMapping._2, getClass.getClassLoader))
     }

src/main/scala/gitbucket/core/plugin/PluginRegistory.scala

@@ -6,7 +6,7 @@ import java.util.Base64
 import javax.servlet.ServletContext
 
 import gitbucket.core.controller.{Context, ControllerBase}
-import gitbucket.core.model.Account
+import gitbucket.core.model.{Account, Issue}
 import gitbucket.core.service.ProtectedBranchService.ProtectedBranchReceiveHook
 import gitbucket.core.service.RepositoryService.RepositoryInfo
 import gitbucket.core.service.SystemSettingsService.SystemSettings
@@ -17,6 +17,7 @@ import io.github.gitbucket.solidbase.Solidbase
 import io.github.gitbucket.solidbase.manager.JDBCVersionManager
 import io.github.gitbucket.solidbase.model.Module
 import org.slf4j.LoggerFactory
+import play.twirl.api.Html
 
 import scala.collection.mutable
 import scala.collection.mutable.ListBuffer
@@ -32,10 +33,17 @@ class PluginRegistry {
     "md" -> MarkdownRenderer, "markdown" -> MarkdownRenderer
   )
   private val repositoryRoutings = new ListBuffer[GitRepositoryRouting]
+  private val accountHooks = new ListBuffer[AccountHook]
   private val receiveHooks = new ListBuffer[ReceiveHook]
   receiveHooks += new ProtectedBranchReceiveHook()
 
   private val repositoryHooks = new ListBuffer[RepositoryHook]
+  private val issueHooks = new ListBuffer[IssueHook]
+  issueHooks += new gitbucket.core.util.Notifier.IssueHook()
+
+  private val pullRequestHooks = new ListBuffer[PullRequestHook]
+  pullRequestHooks += new gitbucket.core.util.Notifier.PullRequestHook()
+
   private val globalMenus = new ListBuffer[(Context) => Option[Link]]
   private val repositoryMenus = new ListBuffer[(RepositoryInfo, Context) => Option[Link]]
   private val repositorySettingTabs = new ListBuffer[(RepositoryInfo, Context) => Option[Link]]
@@ -43,6 +51,7 @@ class PluginRegistry {
   private val systemSettingMenus = new ListBuffer[(Context) => Option[Link]]
   private val accountSettingMenus = new ListBuffer[(Context) => Option[Link]]
   private val dashboardTabs = new ListBuffer[(Context) => Option[Link]]
+  private val issueSidebars = new ListBuffer[(Issue, RepositoryInfo, Context) => Option[Html]]
   private val assetsMappings = new ListBuffer[(String, String, ClassLoader)]
   private val textDecorators = new ListBuffer[TextDecorator]
 
@@ -99,6 +108,10 @@ class PluginRegistry {
     }
   }
 
+  def addAccountHook(accountHook: AccountHook): Unit = accountHooks += accountHook
+
+  def getAccountHooks: Seq[AccountHook] = accountHooks.toSeq
+
   def addReceiveHook(commitHook: ReceiveHook): Unit = receiveHooks += commitHook
 
   def getReceiveHooks: Seq[ReceiveHook] = receiveHooks.toSeq
@@ -107,6 +120,14 @@ class PluginRegistry {
 
   def getRepositoryHooks: Seq[RepositoryHook] = repositoryHooks.toSeq
 
+  def addIssueHook(issueHook: IssueHook): Unit = issueHooks += issueHook
+
+  def getIssueHooks: Seq[IssueHook] = issueHooks.toSeq
+
+  def addPullRequestHook(pullRequestHook: PullRequestHook): Unit = pullRequestHooks += pullRequestHook
+
+  def getPullRequestHooks: Seq[PullRequestHook] = pullRequestHooks.toSeq
+
   def addGlobalMenu(globalMenu: (Context) => Option[Link]): Unit = globalMenus += globalMenu
 
   def getGlobalMenus: Seq[(Context) => Option[Link]] = globalMenus.toSeq
@@ -135,6 +156,10 @@ class PluginRegistry {
 
   def getDashboardTabs: Seq[(Context) => Option[Link]] = dashboardTabs.toSeq
 
+  def addIssueSidebar(issueSidebar: (Issue, RepositoryInfo, Context) => Option[Html]): Unit = issueSidebars += issueSidebar
+
+  def getIssueSidebars: Seq[(Issue, RepositoryInfo, Context) => Option[Html]] = issueSidebars.toSeq
+
   def addAssetsMapping(assetsMapping: (String, String, ClassLoader)): Unit = assetsMappings += assetsMapping
 
   def getAssetsMappings: Seq[(String, String, ClassLoader)] = assetsMappings.toSeq

src/main/scala/gitbucket/core/service/HandleCommentService.scala

@@ -2,11 +2,10 @@ package gitbucket.core.service
 
 import gitbucket.core.controller.Context
 import gitbucket.core.model.Issue
-import gitbucket.core.model.Profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
+import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.util.SyntaxSugars._
 import gitbucket.core.util.Implicits._
-import gitbucket.core.util.Notifier
 
 trait HandleCommentService {
   self: RepositoryService with IssuesService with ActivityService
@@ -21,7 +20,7 @@ trait HandleCommentService {
       defining(repository.owner, repository.name){ case (owner, name) =>
         val userName = loginAccount.userName
 
-        val (action, recordActivity) = actionOpt
+        val (action, actionActivity) = actionOpt
           .collect {
             case "close" if(!issue.closed) => true  ->
               (Some("close")  -> Some(if(issue.isPullRequest) recordClosePullRequestActivity _ else recordCloseIssueActivity _))
@@ -36,54 +35,55 @@ trait HandleCommentService {
 
         val commentId = (content, action) match {
           case (None, None) => None
-          case (None, Some(action)) => Some(createComment(owner, name, userName, issue.issueId, action.capitalize, action))
-          case (Some(content), _) => Some(createComment(owner, name, userName, issue.issueId, content, action.map(_+ "_comment").getOrElse("comment")))
+          case (None, Some(action)) =>
+            Some(createComment(owner, name, userName, issue.issueId, action.capitalize, action))
+          case (Some(content), _) =>
+            val id = Some(createComment(owner, name, userName, issue.issueId, content, action.map(_+ "_comment").getOrElse("comment")))
+
+            // record comment activity
+            if(issue.isPullRequest) recordCommentPullRequestActivity(owner, name, userName, issue.issueId, content)
+            else recordCommentIssueActivity(owner, name, userName, issue.issueId, content)
+
+            // extract references and create refer comment
+            createReferComment(owner, name, issue, content, loginAccount)
+
+            id
         }
 
-        // record comment activity if comment is entered
-        content foreach {
-          (if(issue.isPullRequest) recordCommentPullRequestActivity _ else recordCommentIssueActivity _)
-          (owner, name, userName, issue.issueId, _)
-        }
-        recordActivity foreach ( _ (owner, name, userName, issue.issueId, issue.title) )
-
-        // extract references and create refer comment
-        content.map { content =>
-          createReferComment(owner, name, issue, content, loginAccount)
-        }
+        actionActivity foreach ( _ (owner, name, userName, issue.issueId, issue.title) )
 
         // call web hooks
         action match {
-          case None => commentId.map { commentIdSome => callIssueCommentWebHook(repository, issue, commentIdSome, loginAccount) }
-          case Some(act) => {
+          case None => commentId foreach (callIssueCommentWebHook(repository, issue, _, loginAccount))
+          case Some(act) =>
             val webHookAction = act match {
-              case "open"   => "opened"
-              case "reopen" => "reopened"
               case "close"  => "closed"
-              case _ => act
+              case "reopen" => "reopened"
             }
-            if (issue.isPullRequest) {
+            if(issue.isPullRequest)
               callPullRequestWebHook(webHookAction, repository, issue.issueId, context.baseUrl, loginAccount)
-            } else {
+            else
               callIssuesWebHook(webHookAction, repository, issue, context.baseUrl, loginAccount)
-            }
-          }
         }
 
-        // notifications
-        Notifier() match {
-          case f =>
-            content foreach {
-              f.toNotify(repository, issue, _){
-                Notifier.msgComment(s"${context.baseUrl}/${owner}/${name}/${
-                  if(issue.isPullRequest) "pull" else "issues"}/${issue.issueId}#comment-${commentId.get}")
-              }
-            }
-            action foreach {
-              f.toNotify(repository, issue, _){
-                Notifier.msgStatus(s"${context.baseUrl}/${owner}/${name}/issues/${issue.issueId}")
-              }
-            }
+        // call hooks
+        content foreach { x =>
+          if(issue.isPullRequest)
+            PluginRegistry().getPullRequestHooks.foreach(_.addedComment(commentId.get, x, issue, repository))
+          else
+            PluginRegistry().getIssueHooks.foreach(_.addedComment(commentId.get, x, issue, repository))
+        }
+        action foreach {
+          case "close" =>
+            if(issue.isPullRequest)
+              PluginRegistry().getPullRequestHooks.foreach(_.closed(issue, repository))
+            else
+              PluginRegistry().getIssueHooks.foreach(_.closed(issue, repository))
+          case "reopen" =>
+            if(issue.isPullRequest)
+              PluginRegistry().getPullRequestHooks.foreach(_.reopened(issue, repository))
+            else
+              PluginRegistry().getIssueHooks.foreach(_.reopened(issue, repository))
         }
 
         commentId.map( issue -> _ )

src/main/scala/gitbucket/core/service/IssueCreationService.scala

@@ -3,11 +3,10 @@ package gitbucket.core.service
 import gitbucket.core.controller.Context
 import gitbucket.core.model.{Account, Issue}
 import gitbucket.core.model.Profile.profile.blockingApi._
+import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.service.RepositoryService.RepositoryInfo
-import gitbucket.core.util.Notifier
 import gitbucket.core.util.Implicits._
 
-// TODO: Merged with IssuesService?
 trait IssueCreationService {
 
   self: RepositoryService with WebHookIssueCommentService with LabelsService with IssuesService with ActivityService =>
@@ -46,10 +45,9 @@ trait IssueCreationService {
     // call web hooks
     callIssuesWebHook("opened", repository, issue, context.baseUrl, loginAccount)
 
-    // notifications
-    Notifier().toNotify(repository, issue, body.getOrElse("")) {
-      Notifier.msgIssue(s"${context.baseUrl}/${owner}/${name}/issues/${issueId}")
-    }
+    // call hooks
+    PluginRegistry().getIssueHooks.foreach(_.created(issue, repository))
+
     issue
   }
 

src/main/scala/gitbucket/core/util/Notifier.scala

@@ -13,87 +13,157 @@ import org.apache.commons.mail.{DefaultAuthenticator, HtmlEmail}
 import org.slf4j.LoggerFactory
 import gitbucket.core.controller.Context
 import SystemSettingsService.Smtp
-import SyntaxSugars.defining
 
-trait Notifier extends RepositoryService with AccountService with IssuesService {
+/**
+ * The trait for notifications.
+ * This is used by notifications plugin, which provides notifications feature on GitBucket.
+ * Please see the plugin for details.
+ */
+trait Notifier {
 
-  def toNotify(r: RepositoryService.RepositoryInfo, issue: Issue, content: String)
-      (msg: String => String)(implicit context: Context): Unit
+  def toNotify(subject: String, msg: String)
+              (recipients: Account => Session => Seq[String])(implicit context: Context): Unit
 
-  protected def recipients(issue: Issue, loginAccount: Account)(notify: String => Unit)(implicit session: Session) =
-    (
-        // individual repository's owner
-        issue.userName ::
-        // group members of group repository
-        getGroupMembers(issue.userName).map(_.userName) :::
-        // collaborators
-        getCollaboratorUserNames(issue.userName, issue.repositoryName) :::
-        // participants
-        issue.openedUserName ::
-        getComments(issue.userName, issue.repositoryName, issue.issueId).map(_.commentedUserName)
-    )
-    .distinct
-    .withFilter ( _ != loginAccount.userName )  // the operation in person is excluded
-    .foreach (
-      getAccountByUserName(_)
-        .filterNot (_.isGroupAccount)
-        .filterNot (LDAPUtil.isDummyMailAddress(_))
-        .foreach (x => notify(x.mailAddress))
-    )
 }
 
 object Notifier {
-  // TODO We want to be able to switch to mock.
   def apply(): Notifier = new SystemSettingsService {}.loadSystemSettings match {
     case settings if (settings.notification && settings.useSMTP) => new Mailer(settings.smtp.get)
     case _ => new MockMailer
   }
 
-  def msgIssue(url: String) = (content: String) => s"""
-    |${content}<br/>
-    |--<br/>
-    |<a href="${url}">View it on GitBucket</a>
-    """.stripMargin
 
-  def msgPullRequest(url: String) = (content: String) => s"""
-    |${content}<hr/>
-    |View, comment on, or merge it at:<br/>
-    |<a href="${url}">${url}</a>
-    """.stripMargin
+  // TODO This class is temporary keeping the current feature until Notifications Plugin is available.
+  class IssueHook extends gitbucket.core.plugin.IssueHook
+    with RepositoryService with AccountService with IssuesService {
 
-  def msgComment(url: String) = (content: String) => s"""
-    |${content}<br/>
-    |--<br/>
-    |<a href="${url}">View it on GitBucket</a>
-    """.stripMargin
+    override def created(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(issue.content getOrElse "", r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def addedComment(commentId: Int, content: String, issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(content, r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}#comment-$commentId"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def closed(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("close", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def reopened(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("reopen", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+
+    protected def subject(issue: Issue, r: RepositoryService.RepositoryInfo): String =
+      s"[${r.owner}/${r.name}] ${issue.title} (#${issue.issueId})"
+
+    protected def message(content: String, r: RepositoryService.RepositoryInfo)(msg: String => String)(implicit context: Context): String =
+      msg(Markdown.toHtml(
+        markdown         = content,
+        repository       = r,
+        enableWikiLink   = false,
+        enableRefsLink   = true,
+        enableAnchor     = false,
+        enableLineBreaks = false
+      ))
+
+    protected val recipients: Issue => Account => Session => Seq[String] = {
+      issue => loginAccount => implicit session =>
+        (
+          // individual repository's owner
+          issue.userName ::
+          // group members of group repository
+          getGroupMembers(issue.userName).map(_.userName) :::
+          // collaborators
+          getCollaboratorUserNames(issue.userName, issue.repositoryName) :::
+          // participants
+          issue.openedUserName ::
+          getComments(issue.userName, issue.repositoryName, issue.issueId).map(_.commentedUserName)
+        )
+        .distinct
+        .withFilter ( _ != loginAccount.userName )  // the operation in person is excluded
+        .flatMap (
+          getAccountByUserName(_)
+            .filterNot (_.isGroupAccount)
+            .filterNot (LDAPUtil.isDummyMailAddress)
+            .map (_.mailAddress)
+        )
+    }
+  }
+
+  // TODO This class is temporary keeping the current feature until Notifications Plugin is available.
+  class PullRequestHook extends IssueHook with gitbucket.core.plugin.PullRequestHook {
+    override def created(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      val url = s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}"
+      Notifier().toNotify(
+        subject(issue, r),
+        message(issue.content getOrElse "", r)(content => s"""
+          |$content<hr/>
+          |View, comment on, or merge it at:<br/>
+          |<a href="$url">$url</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def addedComment(commentId: Int, content: String, issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(content, r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}#comment-$commentId"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def merged(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("merge", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+  }
 
-  def msgStatus(url: String) = (content: String) => s"""
-    |${content} <a href="${url}">#${url split('/') last}</a>
-    """.stripMargin
 }
 
 class Mailer(private val smtp: Smtp) extends Notifier {
   private val logger = LoggerFactory.getLogger(classOf[Mailer])
 
-  def toNotify(r: RepositoryService.RepositoryInfo, issue: Issue, content: String)
-      (msg: String => String)(implicit context: Context): Unit = {
+  def toNotify(subject: String, msg: String)
+              (recipients: Account => Session => Seq[String])(implicit context: Context): Unit = {
     context.loginAccount.foreach { loginAccount =>
       val database = Database()
 
       val f = Future {
-        database withSession { implicit session =>
-          defining(
-            s"[${r.owner}/${r.name}] ${issue.title} (#${issue.issueId})" ->
-              msg(Markdown.toHtml(
-                markdown         = content,
-                repository       = r,
-                enableWikiLink   = false,
-                enableRefsLink   = true,
-                enableAnchor     = false,
-                enableLineBreaks = false
-              ))
-          ) { case (subject, msg) =>
-            recipients(issue, loginAccount) { to => send(to, subject, msg, loginAccount) }
+        database withSession { session =>
+          recipients(loginAccount)(session) foreach { to =>
+            send(to, subject, msg, loginAccount)
           }
         }
         "Notifications Successful."
@@ -137,6 +207,6 @@ class Mailer(private val smtp: Smtp) extends Notifier {
 
 }
 class MockMailer extends Notifier {
-  def toNotify(r: RepositoryService.RepositoryInfo, issue: Issue, content: String)
-      (msg: String => String)(implicit context: Context): Unit = {}
+  def toNotify(subject: String, msg: String)
+              (recipients: Account => Session => Seq[String])(implicit context: Context): Unit = ()
 }

src/main/twirl/gitbucket/core/issues/issueinfo.scala.html

@@ -112,6 +112,9 @@
   <input type="hidden" name="assignedUserName" value=""/>
 }
 @issue.map { issue =>
+  @gitbucket.core.plugin.PluginRegistry().getIssueSidebars.map { sidebar =>
+    @sidebar(issue, repository, context)
+  }
   <hr/>
   <div style="margin-bottom: 14px;">
     @defining((issue.openedUserName :: comments.map(_.commentedUserName)).distinct){ participants =>