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What to do when a child theme crashes your website

From: WordPress 3: Building Child Themes

Video: What to do when a child theme crashes your website

Working on the Internet, you're bound to run into situations where your site goes down. And working with child themes, it's quite likely that at some point or another, you make a small error that causes the site to either break or go down completely. I like to say that the web is an inherently unstable platform, and we as web developers just work to make it appear as if the web is stable. That is very true for WordPress, because although when everything works fine, WordPress works great, you only need to make a tiny little mistake, and it has enormous consequences for your site.

What to do when a child theme crashes your website

Working on the Internet, you're bound to run into situations where your site goes down. And working with child themes, it's quite likely that at some point or another, you make a small error that causes the site to either break or go down completely. I like to say that the web is an inherently unstable platform, and we as web developers just work to make it appear as if the web is stable. That is very true for WordPress, because although when everything works fine, WordPress works great, you only need to make a tiny little mistake, and it has enormous consequences for your site.

Fortunately, because of how WordPress is built, the fact that the site goes down or breaks doesn't really mean much, because all you have to do is just fix the small error, and it will come back up again. So let me address two very common issues that arise when you work with child themes. The first one is a standard code error. Throughout this course, we have been adding a lot of functions and functionalities to the site editing different pages and different templates. Let me show you what happens if you make a tiny coding error in the wrong place.

I'll open functions.php, and make a code error. So I'll simply delete this curly bracket here. I'll save it, reload the page and my website disappeared. But worse than that, I can't access it at all. I can try to go to wp-admin, nothing. So I cannot access my site at all from the web anymore. And all I did was removed a curly bracket. But the great thing about working with child themes and also about working with WordPress is that when things like that happen, you can force WordPress to revert back to a stable state.

The easiest way to do that is to simply go to your themes folder, and rename the folder for your child theme. So I'll rename this to your child theme, BROKEN, and reload my page. And what happens now is WordPress tries to find the child theme, can't find it, and gives you an error. The themes directory is either empty or doesn't exist. Please check your installation. What really happened was WordPress fell back on a default theme. So now, you have Twenty Eleven activated, or you may have Twenty Twelve activated.

The child theme is still there, but as we know, it doesn't work. So now that it doesn't work, I can go back and edit it so that I can make it work again, and then put it back online. So I can go back into my theme, open functions.php, fix my error, and rename the folder. Then I just have to go back to the site, reload the Themes page, and reactivate Child of Twenty Twelve.

And with that, my site is back online and everything is fine. The second common error is also done in functions.php. But you could accidentally do it other places too. It's very common that people make new functions like these ones. But they use function names that match existing function names either in WordPress or in the parent theme. If you do, you get a double function, and if everything isn't set up to handle double functions, you get massive code errors in the process.

It's very easy to avoid this. All you have to do is give your new functions a proper name that's different from the parent theme function. The general rule is to simply add something like mytheme_ and then the description of the function. Through this course, I have actually added a couple of different names, and to be honest with you, that's a bit sloppy. I should've actually given everything the same name so it's easy to understand. But you get my drift. By saying mytheme_ in front of each function or mychildtheme_ or something like that or even the name of the theme, you're avoiding the chance of anything overwriting the existing theme or crashing with WordPress.

The default in WordPress is that everything is either started with WP or it just spells out the function itself. So if you always add either your own name or the name of the theme or something else at the front of each function, you'll never clash with anything else. WordPress site crashes can be pretty disturbing, but it's very rare indeed that a WordPress site truly goes down. In almost every case, the site crash is caused by either bad code or a conflict in the theme or plug-in.

That means, retracing your steps or if the worst comes to worst, disabling your child theme, will usually get you back up and running just like that.

Show transcript

This video is part of

Image for WordPress 3: Building Child Themes
WordPress 3: Building Child Themes

45 video lessons · 33111 viewers

Morten Rand-Hendriksen
Author

 
Expand all | Collapse all
  1. 6m 59s
    1. Welcome
      1m 6s
    2. Using the exercise files
      1m 34s
    3. What you need to know before watching this course
      1m 29s
    4. Getting the right tools for theme creation
      2m 50s
  2. 17m 2s
    1. What is a WordPress child theme and when should you use it?
      2m 38s
    2. Picking a parent theme
      3m 55s
    3. Making sure you have the Twenty Twelve parent theme
      1m 50s
    4. Creating and activating a basic child theme
      4m 20s
    5. Importing parent theme styles
      4m 19s
  3. 16m 2s
    1. Using the developer tools
      3m 53s
    2. Modifying existing styles
      4m 24s
    3. Adding space between paragraphs
      4m 7s
    4. Changing font family styles
      3m 38s
  4. 31m 47s
    1. Understanding the WordPress template hierarchy
      3m 12s
    2. Modifying existing templates
      2m 33s
    3. Moving the header image
      4m 29s
    4. Adding Related Posts feature to posts
      6m 26s
    5. Creating custom page templates
      5m 43s
    6. Using conditional statements for customized effects
      5m 41s
    7. Creating custom header, footer, and sidebar templates
      3m 43s
  5. 17m 5s
    1. Understanding the different index pages and what they do
      4m 6s
    2. Adding author, date, and time information to the index loop
      7m 15s
    3. Changing the appearance of category index pages
      5m 44s
  6. 43m 5s
    1. Introducing functions.php
      3m 24s
    2. Overriding existing functions
      3m 23s
    3. Adding pagination to index pages
      5m 49s
    4. Adding to existing functions
      3m 21s
    5. Adding a new footer menu to Twenty Twelve
      6m 24s
    6. Adding a new widgetized area to pages
      4m 9s
    7. Adding static content to the sidebar
      7m 44s
    8. Replacing existing functions
      2m 36s
    9. Adding a Google font through a function
      6m 15s
  7. 10m 24s
    1. Adding new featured image sizes
      5m 41s
    2. Adding featured images to posts and pages
      4m 43s
  8. 31m 1s
    1. Adding a welcome message to the front page
      1m 22s
    2. Displaying page content in an index page
      7m 42s
    3. Hooking in a featured image
      4m 34s
    4. Making the welcome message responsive
      6m 27s
    5. Restricting content to the first page of the blog
      4m 22s
    6. Adding a jQuery function to show or hide the welcome message
      6m 34s
  9. 10m 23s
    1. Adding a custom favicon
      3m 58s
    2. Adding a custom screenshot
      2m 29s
    3. Adding footer information
      3m 56s
  10. 7m 14s
    1. What to do when a child theme crashes your website
      4m 38s
    2. Updating parent and child themes
      2m 36s

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