Adding a Heat Map to WordPress

This post was written 1 year 8 months 8 days days old, so is a bit old now. Feel free to read and comment on this post, just remember some things change with time and any facts in this post may not be accurate anymore.

Wanting to learn a bit more about the visitors to this site, I thought installing a heat map on the site would be a good start.

I initially used PicNet Mouse Eye Tracking – this is free, but an advert for the service appears at the foot of your site. However, I soon came across the OpenSource ClickHeat. You can use this on any kind of site and is a PHP-based installation.

After much gnashing of teeth, here’s how I got it installed…

• Download the latest version of ClickHeat and unzip it
• Install this into a folder on your server
• Now, from the address bar of your browser, open up the folder. e.g. If you installed it to www.mysite.com/clickheat, you’d go to this directory in your address bar.
• This will start the installer. I found errors straight away – make sure the config, log and cache folders are writeable.
• Done. You simply need to add the code to start tracking – return to the ClickHeat folder to access your heat map and make settings changes.

To test it’s working, simply append ?debugclickheat to the end of any of your sites URLs.

For WordPress, there is a plugin available, but I couldn’t get this to work. Instead I added the JavaScript (which is generated from the ClickHeat admin screen) directly to my footer.php file in the theme folder, wrapping it in a check to ensure that an admin isn’t signed in (so it doesn’t track my clicking!).

One more problem I cam across – in the ClickHeat admin screens I kept getting the following error…

Warning: ob_start() [ref.outcontrol]: output handler 'ob_gzhandler' cannot be used twice in /xxx/clickheat/index.php  on line 51

Obviously, I’ve replaced the directory path with “xxx” for security reasons.

After some searching around, I decided the best solution was to make a modification to the ClickHeat code itself. Open up the index.php file within the ClickHeat folder and attempt to find the line that starts with the following…

if (@ini_get('zlib.output_compression')

Before this line, add the following…

ob_end_clean();

And that’s worked for me.

I’ll report back on how I get on with ClickHeat.