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Geovanny Junio


Catalyst::Plugin::SimpleMessage - Handle passing multiple types of messages between screens of a web application using session or stash.


In MyApp.pm:

    use Catalyst qr/

In controller where you want to save a message for display on the next page (here, once the "delete" action taken is complete, we are redirecting to a "list" page to show the status [we don't want to leave the delete action in the browser URL]):

        { $c->sm_get_token_param() => $c->sm_session({ message => 'Deleted widget', type => 'success' }) }));

Or, to display an error message:

        { $c->sm_get_token_param() => $c->sm_session({ message => 'Error deleting widget', type => 'danger' }) }));

If you do not need a redirect, you can pass the message using stash:

    $c->sm_stash({ message => 'Your email was not confirmed yet', type => 'warning' });

And, to display the output (here using Template Toolkit and Twitter Bootstrap):

    [% FOREACH item IN c.sm_get() %]
        <span class="alert alert-[% item.type %]">[% item.message %]</span>
    [% END %]


There are a number of ways people commonly use to pass messages between screens in a web application.

  • Using $c->flash: The "flash" feature does provide a mechanism where the application can redirect to an appropriate URL, but it can also lead to a race condition where the wrong status message is displayed in the wrong browser window or tab (and can therefore be confusing to the users of your application).

  • Query parameters in the URL: This suffers from issues related to long/ugly URLs and leaves the message displayed even after a browser refresh.

This plugin attempts to address these issues through the following mechanisms:

  • Stores messages in the $c->session so that the application is free to redirect to the appropriate URL after an action is taken.

  • Associates a random 8-digit "token" with each message, so it's completely unambiguous what message should be shown in each window/tab.

  • Only requires that the token (not the full message) be included in the redirect URL.

  • Automatically removes the message after the first time it is displayed. That way, if users hit refresh in their browsers they only see the messages the first time.



Returns an array ref with messages sent through $c->sm_session and $c->sm_stash. You can send messages through $c->sm_session and $c->sm_stash and both will be available, messages sent throught stash are available only for the current request.


Alias for sm_get_messages


Return the token_param name. Default is "__sm"


Send messages through the session and return a token. You can send multiple messages:

    my $token = $c->sm_session({ message => 'Product added with success', type => 'success' }, { message => 'You must define a price before selling', type => 'warning' });
    $c->response->redirect($c->uri_for($self->action_for('list'), { $c->sm_get_token_param() => $token }));


Alias for sm_set_messages_session


Send messages through the stash. You can send multiple messages:

    my $token = $c->sm_stash({ message => 'You account is active', type => 'info' }, { message => 'You do not have credit', type => 'danger' });

Messages sent through stash will be available only for the current request.


Alias for sm_set_messages_stash



The location inside $c->session where messages will be stored. Defaults to "__sm".


The location inside $c->stash where messages will be stored. Defaults to "__sm".


The name of the URL param that holds the token on the page where you want to retrieve/display the status message. Defaults to "__sm".

Configuration Example

Here is a quick example showing how Catalyst::Plugin::SimpleMessage can be configured

    # Configure Catalyst::Plugin::SimpleMessage
        'Plugin::SimpleMessage' => {
            session_prefix       => '__sm',
            stash_prefix         => '__sm',
            token_param          => '__sm'


Note: You normally shouldn't need any of the information in this section to use Catalyst::Plugin::SimpleMessage.


Handles default values for config and lets them be overriden from the MyApp configuration.





Geovanny Junio, geovannyjs@gmail.com

This module was based on Catalyst::Plugin::StatusMessage. Many thanks to Kennedy Clark (HKCLARK).


This library is free software. You can redistribute it and/or modify it under the same terms as Perl itself.