Table of Contents
- Backup your database
- Check my code out of Github, or create a module directory
- Create a project info YAML file
- Create the necessary subdirectories
- Write the code to display your block
- Clear the caches
- Enable the module
- Place the block module
- See the custom block on your website
- The biggest problem I encountered
- The source code
In this tutorial I’ll demonstrate how to write a simple Drupal 8 “block module.” By this I mean that I’ll show you how to write a simple Drupal 8 module that will display output in a block. When you’re done you will have created a new block that you can place in one or more theme regions.
Dries Buytaert has a good story about how he created the now-defunct Mollom anti-spam service. No word on why they didn’t try to sell the service rather than just shut it down.
After trying a lot of different anti-spam modules with Drupal 8, the best thing I’ve ever done to reduce comment spam is to go to the Drupal admin /admin/structure/types/manage/blog/fields URI, click Edit on the Comments field, and then select the “Anonymous posters may not enter their contact information.” Since I chose that option two days ago I’ve only had one spammy comment show up in my approval list. That field gave spammers a simple way to enter a URL, and without it, the spam seems to have dried up.
I find Drupal 8 module management to be confusing, but one thing I’ve learned is that you can install and remove Drupal 8 modules with Composer at the command line.
Adding a Drupal 8 module with Composer
The short story is that to add a new module — such as the reCAPTCHA anti-spam module — you type this command at the command line (in the root directory of your Drupal 8 website) to install it:
As I noted five days ago, Mollom went out of business so I had to switch this Drupal 8 website to use a different module to control comment spam. I ended up adding two modules that work together, but the side effect of using their best features is that they end up disabling Drupal 8 page caching. This image clearly shows the result that disabling page caching has on CPU use.
I’m not sure why, but on April 3, 2018, the people behind the Mollom anti-spam module for Drupal basically went out of business. This meant that I either had to disable comments on this site (which I did for a while), or look at other anti-spam modules, which I did over the weekend.
As a brief note today, if you want to know if your Drupal 8 web pages are being cached, take a look at the headers that are returned by your Drupal 8 URLs. Here’s an example using the
On April 3, 2018 this website suddenly got a ton of spam comments. Fortunately I caught the probably very quickly, and turned off the ability for people to post comments here. When I checked into the problem I found that Mollom — created by the same person who created Drupal — basically went out of business on April 2nd. (I’m sure there was some warning about this decision, but I sure didn’t get it.)
I’m often surprised when people who offer a free service shut down that service without asking a simple question: “Would you be willing to pay for this service, and if so, how much?”
(I’ll re-enable the ability to post comments here when I find a good replacement for Mollom.)