[ ← blog / drupal ](/) Mar 05, 2024  ·  \#drupal  ·  4 min read # Improving the Drupal theme starterkit and theme generation experience Wanting to follow up on our work at MidCamp 2023 with the [Development Settings form](https://mglaman.dev/blog/simplifying-frontend-developer-experience-drupal-click-button), Mike Herchel wanted to jam on another issue to improve the life of frontend developers. Drupal provides a way to [generate themes from starterkit themes](https://www.drupal.org/docs/core-modules-and-themes/core-themes/starterkit-theme). Drupal core provides the Starterkit theme, and contributed themes can also mark themselves as a starterkit theme. All a theme has to do is have `starterkit: true` in their `info.yml` file. And that's it! Optionally, a specifically named PHP file can be provided in the theme for specific processing to finish generating the new theme. Unfortunately, the experience of creating starterkit themes currently involves writing a lot of PHP code to make the required file alterations. Mike [opened an issue](https://www.drupal.org/project/drupal/issues/3364885) to simplify this process. This feedback arose while trying to [make the Olivero theme a starterkit](https://www.drupal.org/project/drupal/issues/3301173). And that is how I spent my spare time at Florida DrupalCamp! I was hacking away at this issue to provide test coverage and fix a few bugs in the code. The issue was 90% of the way there, thanks to the work of [Andy Blum](https://www.drupal.org/u/andy-blum). Getting the community to try the enhancements and provide feedback would be great! [Making a theme compatible with core's theme generator is too difficult Making a theme compatible with Drupal core's theme generator tool is very difficult. Theme generator was introduced in 9.3, and in two years the only theme (that I know of) that is clonable is core's starterkit theme. I believe that the reason is that making a theme compatible is too difficult. Within the issue to make Olivero compatible ([#3301173]), we need 240 lines of fairly complicated PHP. This is unreasonable for a themer to do, and most don't have the necessary skillset to do so. Plan This MR introduces a new way to have the generate-theme command clone your theme. https://www.drupal.org/project/drupal/issues/3364885 ![Making a theme compatible with core's theme generator is too difficult](https://www.drupal.org/sites/all/themes/bluecheese/images/og.jpg) ](https://www.drupal.org/project/drupal/issues/3364885) ## Adding the `starterkit.yml` starterkit file Instead of relying on the `starterkit: true` property in a theme's `info.yml` to determine if it is a starterkit theme, there will be a new `starterkit.yml` file. This allows customizations to be controlled in the starterkit when generated into a new theme. In the issue's current state, it supports four properties: - `ignore`: files to ignore when generating the new theme. - `no_edit`: files where the contents will not be modified. - `no_rename`: files that won't be renamed. - `info`: modifications to be made to the generated theme's `info.yml` file. ### Ignoring files Take for example that the Olivero theme contains tests in the `tests`. These tests are required for Drupal core but not when a theme is generated from Olivero. The theme also contains a `post_update.php` file that executes an upgrade for existing sites. This file isn't needed for a newly generated theme, as it has never been installed. The `starterkit.yml` allows defining an array of files or glob patterns in the `ignore` key. With the following in its `olivero.starterkit.yml`, these files would not be copied into the new theme. ```yaml ignore: - tests/* - olivero.post_update.php ``` Additionally, glob patterns such as `/js/**/*.test.js` can ignore files of a specific name in a directory and its subdirectories. ### Skipping the modification of files We have patterns to match the machine name, label, camel case, Pascal case, and title case. This is required to make sure hooks work. Taking from Olivero, the `olivero_preprocess_html` hook would have to be renamed to match the new theme's name. Files must be also be renamed so that Drupal detects the theme, such as the `info.yml` and `.theme` files. However, there may be specific files that *should not* be processed this way. Both `no_edit` and `no_rename` control the modification of files to handle the replacement of the starterkit's name. I am honestly torn about whether these should be two or just one operation. But this helps keep it more flexible. ```bash no_edit: [] no_rename: [] ``` Glob patterns such as `/**/*.css` can ignore files of a specific name in a directory and its subdirectories. I honestly cannot think of a great example of a use case for this. Perhaps if there was a starterkit named after a frontend framework, like [the Tailwind CSS starterkit](https://git.drupalcode.org/project/tailwindcss). If that starterkit's machine name was `tailwind` versus `tailwindcss`, I can see where there would be editing and renaming conflicts (example: `src/tailwind.pcss` and `tailwind.config.js`.) ### Controlling the generated theme's `info.yml` The starterkit's `info.yml` will be used after being modified for naming references. The `info` key allows controlling more of these values. ```yaml info: hidden: null version: 1.0.0 ``` When using a `null` value, the key will be removed. In the above example, it ensures the `hidden` flag is removed. This will also add `version: 1.0.0` to the generated theme's `info.yml`. This allows adding additional information for the generated themes that may not need to belong in the starterkit's `info.yml` file. Such as providing a new default `description` value if one is not provided to the `generate-theme` command. ![](/themes/custom/mglaman/images/headshot.webp)Thanks for reading I write about Drupal, PHP, and the quiet infrastructure behind large sites — caching, config, and testing. New posts land every week or two. [Subscribe via RSS →](/rss.xml) [About me →](/about-me) [← Older Verifying your Drupal site's configuration against changes from dependency updates ](/blog/verifying-your-drupal-sites-configuration-against-changes-dependency-updates) [Newer → Drupal has made contributing to open source a marketing opportunity ](/blog/drupal-has-made-contributing-open-source-marketing-opportunity)