Let's say that I'm fetching some images from an API in the App component.

Then I want to pass it to the component responsible to rendering images. But this component is not a direct child to the App component. It is the child of a direct child of App component.

Here's how I would pass the images array down to the image component, but I feel like it might not be the best approach.

But what would happen if this hierarchy gets more complex - even just by one more component:

Intuitively, it might not be the best thing.

So, what would be the best way to pass the images array down to the image component, if there are many other children between them?

CodePudding user response：

The problem is usually called Prop Drilling in the React world: https://kentcdodds.com/blog/prop-drilling

A few options:

• Passing props may not be that bad. If the app is small, is a very modular -and easy to unit test- option . You can reduce the verbosity by using prop spread: <Comp {...props} /> and by keeping your component interfaces similar. (many people dislike prop spreading as you can unintentionally pass unsupported props, but if you use TypeScript the compiler will catch that).

• You can use a React Context: https://reactjs.org/docs/context.html (as other mention in the comments). However, keep an eye on how your context objects are defined (keep them small). React will re-render all the childs using the context when the value changes, is not smart enough to automatically detect changes at the property level. Frameworks like Redux or Zustand use other mechanisms to allow a granular control of the shared state (you'll see examples of a useSelector hook).

• You can also take a look to a state management framework (Zustand is my favorite, but Redux is more popular). However, it may be an overkill for small things.

My personal choice is to start with prop drilling, it's easier to modularize and unit test. Then you can think on your app in layers: upper layers depend on a context (or a state framework), and lower layers receive properties. That helps when you want to refactor and move reusable components to other projects.