---
title: Easy feature flags
date: 2024-12-22
permalink: daily/2024/12/22/feature-flags
tags:
  - software-development
  - drupal
  - php
  - sculpin
cta: ~
snippet: |
  Have you tried feature flags (aka feature toggles)? This is how I used a feature flag when swapping my podcast player.
---

I recently [switched to self hosting][0] the MP3 files for the episodes of the Beyond Blocks podcast.

The first step was to upload the files, followed by [updating the player][1] on the episode pages to use the HTML audio element.

As I didn't want the player to switch immediately, I wrapped the new code in a feature flag (or feature toggle) to keep the original player active.

Later, I could swap the player by enabling the feature flag.

## How I did it

Feature flagging is a straight forward concept.

You isolate the code you want to be togglable within a conditional - i.e. an `if` statement - that you can easily change in the future.

My website built with Sculpin, so I can add `self_host_podcast_episodes: false` to my sculpin_site.yml file.

This will be available as `site.self_host_podcast_episodes`  and I can use this in my code to show the appropriate player.

Something like:

```twig
{% verbatim %}
{% if site.self_host_podcast_episodes %}
  Show the new player.
{% else %}
  Show the old player.
{% endif %}
{% endverbatim %}
```

## Here's the thing

I like feature flags as you can separate deploying a feature from releasing it.

The code can be deployed but not active until the feature is enabled.

It's easy to enable, and easy to revert if needed.

In Drupal applications, I use the [Feature Toggle module][2], so I can toggle feature flags by logging in and updating a checkbox.

I also [wrote a module][3] with a Twig function so I can check if a feature toggle is enabled directly in a Twig template - the same as I'm doing in Sculpin.

[0]: {{site.url}}/daily/2024/12/18/self-hosting-podcast
[1]: {{site.url}}/daily/2024/12/19/working-iteratively
[2]: https://www.drupal.org/project/feature_toggle
[3]: https://www.drupal.org/project/feature_toggle_twig