Redmine

    # send e-mail notify for user when he added as watcher in issue

    current_user_add_watcher = User.current

    @watchables.each do |issue|

      Mailer.deliver_issue_watcher_add(issue, current_user_add_watcher, users)

    end

    user = Principal.find(params[:user_id])    # User who is being removed from the watchers

    # send e-mail notify for user when he deleted as watcher in issue

    current_user_delete_watcher = User.current

    if params["object_type"] == "issue"

      issue = Issue.find(params['object_id'])

      Mailer.deliver_issue_watcher_delete(issue, user, current_user_delete_watcher)

    end

  # Builds a mail for notifying user about a new watcher

  def issue_watcher_add(user, issue, current_user_add_watcher)

    @current_user_add_watcher = current_user_add_watcher

    @issue = issue

    @user = user

    @author = issue.author

    @issue_url = url_for(:controller => 'issues', :action => 'show', :id => issue)

    @table = Text::Table.new

    @mail_signature = mail_signature_for(user, issue)

    subject = "[##{issue.id} - #{issue.tracker.name}]"

    subject += " (#{l(:field_watcher)})"

    subject += " #{issue.subject}"

    subject += "   [#{issue.project.name}]"

    mail :to => user,

      :subject => subject

  end

  # Notifies users about a new watchers.

  # Example:

  #   Mailer.deliver_issue_watcher_add(issue, current_user_add_watcher, users)

  # Notifies users when they were ADDED as an watcher to issue

  def self.deliver_issue_watcher_add(issue, current_user_add_watcher, users)

    # if 'issue_updated' in Admin -> Settings -> tab Notifications in Redmine is checkboxed

    if Setting.notified_events.include?('issue_updated')

      notified = users

      # if 'notified' contain <Groups> then divided into separate users

      notified = notified.map {|n| n.is_a?(Group) ? n.users : n}.flatten

      notified.uniq!

      users = notified

      users.each do |user|

        issue_watcher_add(user, issue, current_user_add_watcher).deliver_later

    end

    end

  end

  # Builds a mail for notifying user about a DELETE watcher

  def issue_watcher_delete(user, issue, current_user_delete_watcher)

    @current_user_delete_watcher = current_user_delete_watcher

    @issue = issue

    @user = user

    @author = issue.author

    @issue_url = url_for(:controller => 'issues', :action => 'show', :id => issue)

    @table = Text::Table.new

    @mail_signature = mail_signature_for(user, issue)

    subject = "[##{issue.id} - #{issue.tracker.name}]"

    subject += " (#{l(:field_watcher)})"

    subject += " #{issue.subject}"

    subject += "   [#{issue.project.name}]"

    mail :to => user,

      :subject => subject

  end

  # Notifies users about a deleting watchers.

  # Example:

  #   Mailer.deliver_issue_watcher_delete(issue, user, current_user_delete_watcher)

  # Notifies users when they were DELETED as an watcher to issue

  def self.deliver_issue_watcher_delete(issue, user, current_user_delete_watcher)

    # if 'issue_updated' in Admin -> Settings -> tab Notifications in Redmine is checkboxed

    if Setting.notified_events.include?('issue_updated')

      notified = [user]

      # if 'notified' contain <Groups> then divided into separate users

      notified = notified.map {|n| n.is_a?(Group) ? n.users : n}.flatten

      notified.uniq!

      users = notified

      users.each do |user|

        issue_watcher_delete(user, issue, current_user_delete_watcher).deliver_later

      end

    end

  end

<p>You have been added to the watchers in issue. Added <%= @current_user_add_watcher %>.</p>

<hr>

<%= l(:text_issue_added, :id => link_to("##{@issue.id}", @issue_url), :author => h(@issue.author)).html_safe %>

<hr>

<%= render :partial => 'issue', :formats => [:html], :locals => { :issue => @issue, :user => @user, :issue_url => @issue_url } %>

You have been added to the watchers in issue. Added <%= @current_user_add_watcher %>.

------------

<%= l(:text_issue_added, :id => "##{@issue.id}", :author => @issue.author) %>

----------------------------------------

<%= render :partial => 'issue', :formats => [:text], :locals => { :issue => @issue, :user => @user, :issue_url => @issue_url } %>

<p>You have been removed from the watchers in issue. Removed <%= @current_user_delete_watcher %>.</p>

<hr>

<%= l(:text_issue_added, :id => link_to("##{@issue.id}", @issue_url), :author => h(@issue.author)).html_safe %>

<hr>

<%= render :partial => 'issue', :formats => [:html], :locals => { :issue => @issue, :user => @user, :issue_url => @issue_url } %>

You have been removed from the watchers in issue. Removed <%= @current_user_delete_watcher %>.

------------

<%= l(:text_issue_added, :id => "##{@issue.id}", :author => @issue.author) %>

----------------------------------------

<%= render :partial => 'issue', :formats => [:text], :locals => { :issue => @issue, :user => @user, :issue_url => @issue_url } %>