Children as props

React chapter 90 · Advanced React · ch.2 · source: Nadia Makarevich, Advanced React, Chapter 2 (elements as children)

The problem

A panel owns a highlight toggle and also renders a heavy body inline. Toggle re-renders that body. You cannot move the state down (89) because the panel needs it. memo fails if the parent passes a new object every time.

The pattern that fixes it

The parent that does not have the toggle creates the heavy element and passes it as children. When the panel re-renders, children is the same element object — React skips the heavy tree. Slots (5) are this API for libraries.

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