2

I know React suspense is new and hasn't been officially released for production yet but I was wondering what the main benefits of it are/or using it would be?

I can't see anything it does as being "new" or replacing something that doesn't already exist?

I know it allows me to load stuff from top to bottom but I can do that anyway in react using my own components

can anyone give me some ideas as to what it may be good for?

Red Baron
  • 7,181
  • 10
  • 39
  • 86

2 Answers2

2

it has several benefits to use:

  1. it makes code splitting easy
  2. (with new usecase) it makes data fetching so easy! Read this
  3. it just suspends your component rendering and renders a fallback component until your component makes itself ready to show, by that you can create a skeleton flow for your async components so easily event with a simple UI ( imagine instead of created a loading login by useState Api or something else )

these were just simple benefits of Reacts Suspense/lazy api.

amdev
  • 6,703
  • 6
  • 42
  • 64
  • All without having to write “isLoading” even once! – evolutionxbox Feb 15 '20 at 15:45
  • point 1, I don't know much about. point 2, data fetching is already easy, no? and point 3, I can use a ternary to display a loading spinner until the data has been fetched. still struggling to see why it's so great? or is it a preference thing? – Red Baron Feb 15 '20 at 15:46
  • point 1, if you use something like `react-loadable` you would understand how much easy it became, point 2 describes all what you need to know about, point 3 => ok , but common react just offers that to developers, which is more reliable that even simple our ternery operations – amdev Feb 15 '20 at 19:26
0

First of all, I would like to mention that Suspense is officially released since React 16.6. It is production-ready and it is not limited only to code-splitting. Any asynchronous code can be integrated with it.

As of the benefits, consider the following use-case:

  • We have several components that all use some asynchronous code inside them (like fetching remote resources)
  • We need to display a loading indicator until all components are finished doing their job
  • We need to display an appropriate error if some of the components have failed to do their duty

Old way

The good old way of doing this would be:

  • Create a wrapper component for showing loading indicator and error messages
  • Keep track of loading and error state inside of each component and inform the wrapper component of state changes

Does this all look like unnecessary, hard to change boilerplate? Yes, it does).

New way

React introduced the Suspense component and Error Boundaries to eliminate this boilerplate and to declaratively describe the desired behavior.

Check this out:

<Exception fallback="An error has occured">
  <Suspense fallback="Loading...">
    <OurComponent1 />
    <OurComponent2 />
    <OurComponent3 />
  </Suspense>
</Exception>

Example

Suppose we want to fetch users' data from the remote resource.

const fetchUsers = async () => {
  const response = await fetch("https://jsonplaceholder.typicode.com/users");
  const users = await response.json();
  console.log("Users data", users);
  return users;
};

I will use makeSuspendableHook to integrate our asynchronous fetch within <Suspense> and Error boundary.

const useUsers = makeSuspendableHook(fetchUsers());

In our component, all we should care about is the actual data and its representation.

const Users = () => {
  const users = useUsers();
  return (
    <div>
      List fetched users:
      <ul>
        {users.map(({ name }) => (
          <li>{name}</li>
        ))}
      </ul>
    </div>
  );
}

Finally, I will use Exception as an Error Boundary implementation to stitch everything together.

export default () => (
  <Exception fallback="An error has occurred">
    <Suspense fallback="Waiting...">
      <Users />
    </Suspense>
  </Exception>
);

Play with web example at codesandbox.io

Play with native example at snack.expo.io

Igor Sukharev
  • 2,467
  • 24
  • 21