Set up and use a child theme

Sometimes, you might need to customize your theme or WooCommerce beyond what is possible via the options. These guidelines will teach you the basics of how to go about customizing your site by using a child theme.

Before we start it’s important that you understand what a child theme is. In short, a child theme is a layer that you put on top of the parent theme to make alterations without having to develop a new theme from scratch. There are two major reasons to use child themes:

• Theme developers can use child themes as a way to offer variations on a theme, similar to what we do with the Storefront child themes
• Developers can use child themes to host customizations of the parent theme or any plugin on the site since the child theme will get priority over the plugins and parent theme

Read this guide from the WordPress Codex.

Download a sample Storefront child theme to get started if you want to customize a website using Storefront as the theme.

Before customizing a website, you should always ensure that you have a backup of your site in case anything goes wrong. More info at: Backing up WordPress content.

To get started, we need to prepare a child theme.

First, we need to create a new stylesheet for our child theme. Create a new file called style.css and put this code in it:

/* 
Theme Name: Child Theme 
Version: 1.0 
Description: Child theme for Woo. 
Author: Woo
Author URI: http://woocommerce.com 
Template: themedir */

Next, we need to change the Template field to point to our installed WooTheme. In this example, we’ll use the Storefront theme, which is installed under wp-content/themes/storefront/. The result will look like this:

/* 
Theme Name: Storefront Child 
Version: 1.0 
Description: Child theme for Storefront. 
Author: Woo
Author URI: http://woocommerce.com 
Template: storefront 
*/  

/* --------------- Theme customization starts here ----------------- */

Note: With Storefront, you do not need to enqueue any of the parent theme style files with PHP from the theme’s functions.php file or @import these into the child themes style.css file as the main parent Storefront theme does this for you.

With Storefront, a child theme only requires a blank functions.php file and a style.css file to get up and running.

You can upload the child theme either through your FTP client, or using the Add New theme option in WordPress.

• Through FTP. If you’re using FTP, it means that you go directly to the folders of your website. That means you’ll need FTP access to your host, so you can upload the new child theme. If you don’t have this, you should talk to your host and they can give you your FTP login details, and then download an FTP program to upload your files.
• Through the WP Dashboard. If you create a .zip file of your child theme folder you can then simply upload that to your site from the WordPress > Appearance > Themes > Add New section.

Once you’ve done that, your child theme will be uploaded to a new folder in wp-content/themes/, for example, wp-content/themes/storefront-child/. Once uploaded, we can go to our WP Dashboard > Appearance > Themes and activate the child theme:

Your child theme is now ready to be modified. Currently, it doesn’t hold any customization, so let’s look at a couple of examples of how we can customize the child theme without touching the parent theme.

Let’s do an example together where we change the color of the site title. Add this to your /storefront-child/style.css:

.site-branding h1 a {
   color: red; 
}

After saving the file and refreshing our browser, you will now see that the color of the site title has changed!

But wait, there’s more! You can do the same with the template files (*.php) in the theme folder. For example if w, wanted to modify some code in the header, we need to copy header.php from our parent theme folder wp-content/themes/storefront/header.php to our child theme folder wp-content/themes/storefront-child/header.php. Once we have copied it to our child theme, we edit header.php and customize any code we want. The header.php in the child theme will be used instead of the parent theme’s header.php.

The same goes for WooCommerce templates. If you create a new folder in your child theme called “WooCommerce”, you can make changes to the WooCommerce templates there to make it more in line with the overall design of your website. More on WooCommerce’s template structure can be found here.

The functions.php in your child theme is loaded before the parent theme’s functions.php. If a function in the parent theme is pluggable, it allows you to copy a function from the parent theme into the child theme’s functions.php and have it replace the one in your parent theme. The only requirement is that the parent theme’s function is pluggable, which basically means it is wrapped in a conditional if statement e.g:

if (!function_exists("parent_function_name")) {
      parent_function_name() {
           ...
      } 
}

If the parent theme function is pluggable, you can copy it to the child theme functions.php and modify the function to your liking.

WordPress has a few things that it handles differently in child themes. If you have a template file in your child theme, you have to modify how WordPress includes files. get_template_directory() will reference the parent theme. To make it use the file in the child theme, you need to change use get_stylesheet_directory();.

More info on this from the WP Codex

Although we do offer basic child theme support that can easily be answered, it still falls under theme customization, so please refer to our support policy to see the extent of support we give. We highly advise anybody confused with child themes to use the WordPress forums for help.

Download the sample child theme at the top of this article to get started. Place the child theme in your wp-content/themes/ folder along with your parent theme.