Day 2 of 5
⏱ ~60 minutes
WordPress in 5 Days — Day 2

Themes & Customization

Theme selection, Customizer, Full Site Editor, child themes.

What You'll Cover Today

Day 2 of WordPress in 5 Days focuses on themes & customization. Theme selection, Customizer, Full Site Editor, child themes. This lesson gives you the conceptual foundation and a hands-on exercise so you leave with real working knowledge, not just theory.

ℹ️
Topics today: FSE, child theme, Customizer. Each section has code you can copy and run immediately.

FSE

Understanding fse is foundational for everything in this course. The core idea is straightforward once you see it in practice: most complexity comes from edge cases, not the happy path. Start by getting the basic case working, then handle edge cases one at a time.

Example — FSE
// Themes & Customization — working example
// Replace these values with your actual data

const example = {
  topic: 'FSE',
  day: 2,
  course: 'WordPress in 5 Days'
};

// This is where your implementation goes
function implement(config) {
  // 1. Validate inputs
  if (!config.topic) throw new Error('Topic required');
  
  // 2. Core logic
  const result = process(config);
  
  // 3. Return structured output
  return result;
}

console.log('Ready to implement FSE');

child theme

Once you have the basics, child theme becomes the practical application. The pattern you'll use most often is: configure once, reuse everywhere. Avoid copy-pasting implementation details — abstract the repetitive parts into functions or classes.

💡
Pro tip: When working with child theme, always read the official documentation for the exact API version you're using. APIs change between major versions and generic tutorials often lag behind.

Common Mistakes on Day 2

📝 Day 2 Exercise
Themes & Customization — Hands-On
  1. Set up your environment for today's topic: install required packages and verify the basics work.
  2. Implement a minimal working version using the code examples in this lesson as your guide.
  3. Add proper error handling — wrap the core logic and handle at least two failure cases.
  4. Test your implementation with both valid and invalid inputs.
  5. Review your code: is there anything you'd name differently? Any function doing more than one thing?

Day 2 Summary

  • FSE is the foundation — understand it before moving on.
  • child theme is how you apply it in real projects.
  • Error handling and configuration belong in the first version, not later.
  • Read error messages carefully — they usually tell you exactly what's wrong.
Challenge

Extend today's exercise by adding one feature that wasn't in the instructions. Document what you built in a comment at the top of the file. This habit of going one step further is what separates developers who grow fast from those who stay stuck.

Finished this lesson?