I would like that feature too.

Patch for review (submitted to [Piwik-hackers] by Christoph Moseler).

http://lists.piwik.org/pipermail/piwik-hackers/2008-December/000548.html

I created a plugin that could allow anybody to opt out of being tracked. It works, but I need help for creating a nice widget and/or API that allows users to do so.

Current state:
Adds a widget (Special > Blocking Cookie) with a short message and a link to toggle tracking, clicking that link enables/disables tracking but doesn't take you back to the dashboard.

I thought of a link (button) to click which then replaces the widget content with the updated status message and a new link, but my jQuery code didn't work was I wanted.

Attachment: much cleaner version, less hardcoded, delete cookie if no site is excluded from tracking, user is sent back to dashboard (renamed widget, delete and add new!)
BlockingCookie.php

I had a quick look at plugin;

Feedback:

• html could be extracted in templates
• code to create the cookie should be in an API.
  • instead of building your URLs manually, you can reuse Piwik_Url::getCurrentQueryStringWithParametersModified( $params )
• security: creating the cookie should only be available for users with a "view" access and that are logged in.

Also ideally we would like to add this feature in the admin section of the website, with a link to create a special cookie to be excluded from all websites in this Piwik.

it has grown a little bit :) -> v0.3

• API to exclude from one or all sites (includes sites that are not yet created)
• API to check if excluded from one or all sites
• uses a little template for the widget
• API checks if user has view access for the site he wants to set the cookie for
  • Please check that, it seems to work but I'm unexperienced which checks Piwik does anyways. My second test user was not able to use a modified link but I didn't see any error message because of my redirect.

Attachment:
BlockingCookie-0.3.tar.gz

Unless there are reasonable use cases where someone might want to deactivate the SitesManager, I've moved #554 to the same milestone as it would be a logical extension to integrate the per-site exclusion UI into the SitesManager UI.

Note: cookie exclusion will not be possible "per website"; there will be a global cookie that would disallow tracking for all websites in the Piwik installs. we already have problems with the number of cookies (see #409). We could have a cookie that contain all website IDs to exclude, but this would not work and cause errors when the Piwik contains dozens/hundreds of websites (which is a more and more common use case that we def want to handle gracefully)

For finer grain control over which users are excluded from which websites, the IP exclusion would be the proper solution to use.

black silence: please advise if you're able to make Matt's proposed changes for the upcoming release. Your help is appreciated.

I'll do it at the same time as #43

(In [2142]) Fixes #5462 Adding cookie exclude feature in the user settings page; will exclude visits from all websites tracked in the Piwik instance.

(In [2143]) Refs #5462 anonymous user can't set the cookie (csrf protection)