If you are working in WordPress and are thinking about modifying the core WordPress code I’d like to tell you why you shouldn’t. I’ll start with a reminder that WordPress has created both plug-in and theme capabilities to help customize every part of WordPress including looks and functionality. Given you can accomplish what you need using these tools, hacks shouldn’t be needed and are not recommended.
Reasons why you shouldn’t hack WordPress core files:
- There’s almost always a solution that doesn’t involve hacking core files
- Almost all situations should be handled with a hook or custom plug-in
- Upgrading to the latest version or security patch will overwrite your changes
- Core file changes could cause other plug-ins to not work correctly
- Makes it more difficult for other developers to debug or solve issues
Modifying the core files is a quick fix that will likely end up more costly than doing it correctly the first time or the functionality could just disappear on the next upgrade. It is more likely among amateur and beginner developers that are not aware of the correct way to implement the functionality. I’m not saying you will never have to edit the core files because there is that chance you may find a bug. But in that case you need to report it to WordPress so they can fix it in the next upgrade.
So next time you’re working with WordPress take some time to look through all the WordPress documentation out there and I guarantee you there is a better way of solving the issue that will not interfere with future development and updates.
As for beginners to WordPress I highly recommend the print and PDF version of the book Digging Into WordPress by Chris Coyier & Jeff Starr. It is the best WordPress book I’ve come across and on my top 3 books of all time. I cannot express my love of the spiral binding (I wish all tech/developer books did this), the large and colorful print and screenshots throughout the book and most importantly the content itself covers everything you would want to know in a detailed, accurate and easy to follow way.Link to article