Add daily email for 2025-03-17

An example of feature flagging

source/_daily_emails/2025-03-17.md

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+---
+title: An example of feature flagging
+date: 2025-03-17
+permalink: daily/2025/03/17/feature-flags
+tags:
+  - software-development
+  - feature-flags
+cta: ~
+snippet: |
+  Here are a couple of examples of how I've recently used feature flags on my website.
+---
+
+I've written a number of emails about feature flags, or feature toggles, and am a strong advocate of using them whilst developing new features.
+
+I've used them a couple of times recently on my website so I wanted to share them as examples.
+
+## Experimenting with presentation layouts
+
+Firstly, I wanted to experiment with a different layout for my presentation pages.
+
+They currently have a list of events, embedded slides and a video recording when there is one.
+
+Each event linked to its website, where applicable, and the slides and video were from one of the most recent versions of the presentation.
+
+I wanted to change this so each event would have links to its own slides, example code or demo.
+
+I didn't want to change this yet for all presentations, only [my Sculpin talk][0] as it's the most recent and, if I like it, later apply it to the others.
+
+My website is built with Sculpin, so adding a feature flag was as simple as adding `new: true` to the YAML front matter at the top of the file for that presentation.
+
+This is available as `page.new` in the layout file and I can use this [to load different markup][1].
+
+## Rewriting my CSS
+
+Secondly, I've been wanting to re-style my website with Tailwind CSS 4 and refactor some of the templating.
+
+As this is a change I wanted to be site-wide, I added `new_css: true` to my sculpin_site.yml file.
+
+This time, I was able to use `site.new_css` to [toggle the loaded stylesheet][2] and using Sculpin's environment files - e.g. sculpin_site_dev.yml and sculpin_site_prod.yml - I can be explicit about which stylesheets are used locally and for my live website.
+
+## Summary
+
+Feature flags are a great approach to splitting up large changes into manageable, deployable pieces, and they don't need to be complicated.
+
+Essentially, they are a simple boolean value that you can use to execute different code based on whether it's false or true.
+
+[0]: {{site.url}}/presentations/sculpin
+[1]: https://code.oliverdavies.uk/opdavies/oliverdavies.uk/commit/8b721e63fb64f3c98b81353ca9cec7545d72a595
+[2]: https://code.oliverdavies.uk/opdavies/oliverdavies.uk/commit/fa884644cf5aa233ad22fb28b83c5a0b150b037d