HTML · PRACTICAL GUIDE

HTML data-* Attributes

Attach declarative behavior or metadata without invalid custom attributes.

Practice HTMLLearning path

What this solves

Mark elements for a JavaScript tool controller. This pattern is useful when the business question is clear but a generic tutorial is too abstract.

The rule

Use data-name attributes and access them through dataset.

<button data-run-tool>Run</button>

Real-work checklist

  1. Define the business key and expected grain before writing the formula, query or markup.
  2. Test the pattern on a small known sample where you can verify the answer manually.
  3. Check missing values, duplicates and data types before trusting a large result.
  4. Scale to the real file or database only after the logic is proven.

Common mistake

Do not store sensitive data in the DOM just because data-* is convenient.

Try it next