Core concepts

Everything a component is made of. A reader who has finished these can build a page without looking anything else up.

What you write

• Components — a class with a render(). What it puts on the page is what that returns, which is why a component is not an element.
• JSX — the markup syntax: values, attributes, children, and what is refused.

Where a value lives

• State — a field the render reads, so changing it redraws.
• Props — what a parent hands down, read-only and reactive.
• Derived values — worked out from the two above, cached until they move.
• One per component, or one per item — @compute or @memoized, and the question that decides.

When things happen

• Events — handlers on your own elements, and decorators for the window and the document.
• Lifecycle — created, mounted, updated, destroyed, and what belongs in each.
• Timers — a clock or a delay, cleared for you.
• Subscriptions — a store, a socket, an observer, and the cleanup that comes with it.

Reaching the page itself

• Refs — the real element, to focus, measure, or hand to a library.

Next

• Components — if you are starting here.
• Composition — putting components together once each one works.
• Every decorator, at a glance — the table, once the names are familiar.