Liking is a feature that became wildly popular on Facebook as soon as it was introduced. BuddyPress does not have this ability built in, so if you want to add likes you will need to add a suitable BuddyPress plugin. The BuddyPress Like plugin is a common choice. However, if you want to add both Likes and Dislikes, you may want to consider the new BuddyPress Like Dislike plugin. It is a modification of Alex Hempton-Smith’s BP Like plugin.

Although it includes “dislike” in the title, the plugin operates with more of a ‘Like’ and ‘Unlike’ functionality. It doesn’t actually aggregate the total number of dislikes but rather subtracts from the existing likes. In this way it’s not a total commitment to the ‘disliking’ style functionality.

Here’s how it works:

• Simultaneous like and unlike/dislike buttons are added to activity stream items side by side. Users can either click ‘like’ or an ‘unlike’/'dislike’ which are obviously mutually exclusive.
• Once a user has liked an activity item he can only unlike it and vice-versa

Below you can see the default appearance of the like/unlike buttons on the default BuddyPress theme:

Here’s an example of an activity stream item that has been liked:

Styling the plugin is fairly easy, as the plugin it includes its own stylesheet and icons for like/dislike buttons under the ‘_inc’ folder.

Please note that if you are hoping to preserve the total number of likes and aggregate dislikes, this is not the plugin you’re looking for. The BuddyPress Like Dislike plugin performs more of a balancing functionality between likes and unlikes.

The BuddyPress Like Dislike plugin is not yet available from the WordPress plugin repository, but it is still a free download. Follow the plugin author, @webdwall, on Twitter for all the latest updates. Also, make sure to check out his other recent plugin release that adds attachments to BuddyPress private messages.