Redmine

  before_filter :find_journal, :only => [:edit, :diff, :rollback]

  before_filter :authorize, :only => [:new, :edit, :diff, :rollback]

  def rollback

    (render_403; return false) unless @journal.can_rollback?(User.current)

    if @journal.rollback

      flash[:notice] = l(:notice_successful_update)

    else

      # can't seem to bring in the helper method 'error_messages_for'

      # and injecting it into show.rhtml doesn't seem to work, since 

      # the @issue loses the errors on redirect (due to issue reload)

      flash[:error] = "<ul>" + @journal.errors.full_messages.map {|msg| "<li>" + ERB::Util.html_escape(msg) + "</li>"}.join + "</ul>"

    end

    respond_to do |format|

      format.html { redirect_to :controller => 'issues', :action => 'show', :id => @journal.journalized_id }

      format.api  { render_validation_errors(@issue) }

    end

  end

private

  # rollback the changes in a journal, the journal is destroyed on success

  def rollback(journal)

    # only allow rollback of journal details for the last journal

    (errors.add_to_base(l(:notice_locking_conflict)); return) if !journal.last_valid_journal?(journals)

    # avoid the creation of journals during rollback (see 'attachment removed')

    @rolling_back = true

    # roll back each change detailed by the journal

    journal.details.each do |d|

      case d.property

        # issue attribute change

        when 'attr'; send "#{d.prop_key}=", d.old_value

        # rollback custom field change

        when 'cf'; custom_field_values.each {|v| v.value = d.old_value if v.custom_field_id == d.prop_key.to_i}

        # remove any added attachments (we can't recover removed attachments)

        when 'attachment'; attachments.each {|v| attachments.delete(v) if v.id == d.prop_key.to_i}

      end

    end

    # allow the creation of journals again

    remove_instance_variable(:@rolling_back)

    # destroy the journal once we save the issue changes

    if save(:validate => false)

      journal.rolled_back = true

      journal.save

    end

  end

  def last_valid_journal?(journals)

    self == journals.last

  end

  def can_rollback?(usr = nil)

    user ||= User.current

    editable_by?(user) && (details.empty? || user.allowed_to?(:rollback_issue_notes, project))

  end

  def show?

    !self.rolled_back || User.current.pref.hide_rolled_back_issue_notes == '0'

  end

  # rollback the changes in a journal, the journal is destroyed on success

  def rollback

    # we could have details to rollback, so let the issue take care of this more complicated task

    journalized.rollback(self) || 

    # on failure, collect the error messages from the issue on failure

      (journalized.errors.each_full {|msg| errors.add_to_base(msg)}; false)

  end

  def hide_rolled_back_issue_notes; self[:hide_rolled_back_issue_notes] || '0'; end

  def hide_rolled_back_issue_notes=(value); self[:hide_rolled_back_issue_notes]=value; end

  <% if journal.show? %>

  <% if journal.rolled_back? %>

  <strike>

  <% end %>

    <% if journal.last_valid_journal?(journals) && journal.can_rollback? %>

      <div class="journal-rollback"><%= link_to(image_tag('cancel.png'), {:controller => 'journals', :action => 'rollback', :id => journal}, :confirm => l(:text_are_you_sure), :method => :post, :title => l(:button_rollback_journal)) %>&nbsp;</div>

    <% end %>

  <% if journal.rolled_back? %>

  </strike>

  <% end %>

<% end %>

<p><%= pref_fields.check_box :hide_rolled_back_issue_notes %></p>

  field_hide_rolled_back_issue_notes: "Hide rolled-back issue notes"

  permission_rollback_issue_notes: Rollback issue notes

  button_rollback: Rollback

class AddJournalsRolledBack < ActiveRecord::Migration

  def up

    add_column :journals, :rolled_back, :boolean, :default => 0

  end

  def down

    remove_column :journals, :rolled_back

  end

end