Plugin for Dancer to display flash messages
Latest commit 8ad42a8 Jul 10, 2013 @dams Merge pull request #5 from dagolden/bug-if-flash-error
demonstrate error with conditional in template



Dancer::Plugin::FlashMessage - A plugin to display "flash messages" : short temporary messages


Example with Template Toolkit

In your configuration, make sure you have session configured. Of course you can use any session engine :

  session: "simple"

In your view or in your layout :

  <% IF flash.error %>
    <div class=error> <% flash.error %> </div>
  <% END %>

In your css :

  .error { background: #CEE5F5; padding: 0.5em;
           border: 1px solid #AACBE2; }

In your Dancer App :

  package MyWebService;

  use Dancer;
  use Dancer::Plugin::FlashMessage;

  get '/hello' => sub {
      flash error => 'Error message';
      template 'index';


This plugin helps you display temporary messages, so called "flash messages". It provides a flash() method to define the message. The plugin then takes care of attaching the content to the session, propagating it to the templating system, and then removing it from the session.

However, it's up to you to have a place in your views or layout where the message will be displayed. But that's not too hard (see SYNOPSYS).

Basically, the plugin gives you access to the 'flash' hash in your views. It can be used to display flash messages.

By default, the plugin works using a decent configuration. However, you can change the behaviour of the plugin. See CONFIGURATION



  # sets the flash message for the warning key
  flash warning => 'some warning message';

  # retrieves and removes the flash message for the warning key
  my $warning_message = flash 'warning';

This method can take 1 or 2 parameters. When called with two parameters, it sets the flash message for the given key.

When called with one parameter, it returns the value of the flash message of the given key. The message is deleted from the flash hash in the session.

In both cases, flash always returns the value;


After having set a flash message using flash in your Dancer route, you can access the flash message from within your template. The plugin provides you with the flash hashref, that you can access in your template, for example like this :

  <div class=error> <% flash.error %> </div>

When you use it in your template, the flash message is deleted. So next time, flash.error will not exist.


With no configuration whatsoever, the plugin will work fine, thus contributing to the keep it simple motto of Dancer.

configuration default values

These are the default values. See below for a description of the keys

      token_name: flash
      session_hash_key: _flash

configuration description


The name of the template token that will contain the hash of flash messages. Default : flash


You probably don't need that, but this setting allows you to change the name of the session key used to store the hash of flash messages. It may be useful in the unlikely case where you have key name conflicts in your session. Default : _flash


This software is copyright (c) 2011 by Damien "dams" Krotkine <>.


This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.


This module has been written by Damien "dams" Krotkine <>.