Field Arrays, Dynamic Forms, Validation Flows
Create field arrays, show/hide sections based on values, and implement touched/errors for a clear validation flow.
Field Arrays, Dynamic Forms, Validation Flows is a free React Academy lesson on CoddyKit — lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the React Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why these patterns?
Goal: Scale forms without pain.
- Field arrays (add/remove rows)
- Dynamic sections (show by value)
- Validation flow: touched, submit, errors
Principles for large forms
- Single source of truth for form data
- Stable keys for dynamic rows
- Touched marks user-visited fields
- Validate on submit; optionally on blur
Demo: field array (skills)
A tiny field array: add/remove skill rows with stable ids.
<div id="root"></div>Demo: dynamic section by value
Show extra fields only when needed; keep state in one object.
<div id="root"></div>Demo: touched/errors flow
Track touched and errors. Validate on submit; also on blur for quick hints.
<div id="root"></div>Tips & pitfalls
- Use stable keys for array rows
- Compute errors in a pure function
- Validate on submit; add blur for quick hints; avoid heavy per-keystroke work
Large forms sanity check
Recap
Recap: Manage one form state, render field arrays with stable keys, show dynamic sections by value, and drive validation with touched/errors for clear feedback.
Frequently asked questions
Is the “Field Arrays, Dynamic Forms, Validation Flows” lesson free?
Yes — the full text of “Field Arrays, Dynamic Forms, Validation Flows” is free to read here on the web, and the React Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the React Academy course, upgrade to CoddyKit PRO.
What will I learn in “Field Arrays, Dynamic Forms, Validation Flows”?
Create field arrays, show/hide sections based on values, and implement touched/errors for a clear validation flow. You practise React Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start React Academy?
No prior experience is required. React Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Field Arrays, Dynamic Forms, Validation Flows” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this React Academy lesson?
Yes. Every React Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Field Arrays, Dynamic Forms, Validation Flows
- Async Validation & Dependent Fields
- Performance Tricks for Large Forms