Cached poll

Introduction

The core poll module’s behaviour can be troublesome in combination with a frontend cache (reverse proxy) like Varnish when you want to allow anonymous users to vote on the poll. Poll results will be shown to users who have voted, but depending on which user triggers a cache refresh, this may mean poll results end up in cache and other users, who have not voted, see the results too and are not able to vote. This may get confusing.

This module sets a cookie when a user votes on a poll. This serves two purposes; the user may get served pages containing a poll block showing results, and it will prevent the external cache from caching pages containing poll results.

To submit bug reports and feature suggestions, or to track changes: https://drupal.org/project/issues/cached_poll

Do note that this functionality means that users who have voted will not get pages served from your frontend cache (they will essentially get the same treatment as logged in users). If you have many people voting on polls, this will make your frontend cache much less effective. If this is a problem for you, this is not the module you are looking for.

Requirements

This module has no particular requirements, although it is fairly useless without the core Poll module enabled.

Installation

• Install as you would normally install a contributed Drupal module. See Installing modules (Drupal 7) for further information.

• Make sure your frontend cache is configured to not cache pages when cookies starting with “NO_CACHE” are in the request. For example, many Varnish configurations contain the following line:

  set req.http.Cookie = regsuball(req.http.Cookie, ";(NO_CACHE|SESS[^=]+)=", "; \1=");
  

  You would need to change that to:

  set req.http.Cookie = regsuball(req.http.Cookie, ";(NO_CACHE[^=]*|SESS[^=]+)=", "; \1=");
  

Please do not ask for support with your particular setup; the basic premise is pretty simple, you need to configure things in such a way that this cookie punches a hole in your frontend cache. If you don't know how to do that with your particular setup, seek help in the appropriate support channels for your setup.

Configuration

The module has no menu or modifiable settings. There is no configuration. When enabled, the module will add a cookie to requests for users that have voted (or at least, are considered to have voted by the core Poll module) that may be used to prevent pages containing poll results from being cached.

Maintainers

Current maintainer:

• Eelke Blok (eelkeblok) - https://www.drupal.org/u/eelkeblok

This project has been sponsored by:

• Dutch Open Projects
  
  DOP is a leading Drupal implementer in the Netherlands and provides complete solutions for their customers, from functional design including wireframing to a working Drupal site including maintenance, training and hosting. Visit http://dop.nu (mostly Dutch) for more information.