How Would You Design a Rich Text Editor?
👉 Frontend System Design Essentials — Course: https://icodeit.thinkific.com/courses/frontend-system-design-essentials 👉 Frontend System Design Essentials — Book: https://leanpub.com/frontend-system-design-essentials/ 👉 Frontend System Design Interviews — Book: https://leanpub.com/frontend-system-design-interviews Every LinkedIn post, Facebook comment, or X compose box looks almost like a textarea. You type. You make a word bold. You mention a friend. It feels simple. You are not editing a plain string. You are editing a document with structure — usually a tree that does not look like a tree on the screen. A string is enough until you want bold. HTML is enough until headings, lists, images, mentions, and embeds show up. Then the real question is: what is this document made of? This is Part 1. We look at why the document model should come from the shape of the problem, why the editor needs meaning (a mention is not just a link), and why one Bold click is already a tree transformation. Part 2 is what happens when you start editing that tree. You'll learn: Why a string — and then HTML — stop being enough as requirements grow Why a document tree appears from hierarchy, not from "trees are useful" Why the internal model is meaning, not markup (mentions, user IDs) How a real editor like Lexical uses the same shape Why one UI action (select a word, click Bold) is already a tree change Final takeaway: Representing the document is the easy part. A rich text editor is a tree you have to keep valid while the user edits it — and that is the next video. 📘 MY BOOKS & COURSES 👉 Frontend System Design Essentials (Course): https://icodeit.thinkific.com/courses/frontend-system-design-essentials 👉 Frontend System Design Essentials (Book): https://leanpub.com/frontend-system-design-essentials/ 👉 Frontend System Design Interviews (Book): https://leanpub.com/frontend-system-design-interviews 👉 React Anti-Patterns (Amazon): https://www.amazon.com/dp/1805123971 👉 More Tutorials on Advanced Patterns: https://icodeit.com.au/tutorials/advanced-network-patterns-react 📩 STAY CONNECTED 🧠 Newsletter (system design & clean code): https://juntao.substack.com 🌐 Website & Blog: https://icodeit.com.au 🐦 Twitter / X: http://twitter.com/JuntaoQiu 📺 YouTube (subscribe): https://www.youtube.com/@icodeit.juntao 00:00 That comment box is not a textarea 01:31 About the channel 01:51 A string is enough, until it isn't 02:20 Bold, then HTML, then structure 03:10 What is this document made of? 04:01 The tree appears because the problem has hierarchy 04:33 Render the tree — HTML is one output 05:38 Meaning, not markup: a mention is not a link 06:10 How Lexical models the same shape 06:40 One click is a tree transformation 07:27 Why editing the tree is the next problem #frontend #systemdesign #lexical #javascriptinterview #webdevelopment #frontendsystemdesign