differences-with-fetch.md

Differences with fetch()

Whenever possible, we try to follow standard usage of the fetch() API as closely as possible. There are a few differences between using fetch() and this library, though, which are explained here.

init is not an Object

The second argument to fetch() is an optional object called init. With <Fetch/>, the object has been spread out as props. This change was made for aesthetic reasons: I find it ugly to pass objects as props.

fetch('/posts/2', {
  method: 'PATCH',
  credentials: 'include',
  body: JSON.stringify({ title: 'New post' })
});

<Fetch
  url="/posts/2"
  method="PATCH"
  credentials="include"
  body={JSON.stringify({ title: 'New post' })}
/>

The response body is read for you

When using fetch, you must manually read the body. This library reads it automatically for you. This is because the body is a ReadableStream, and can only be read a single time. It was a requirement that React Request read it for you to support deduplication of requests.

fetch('/posts/2', {
  method: 'PATCH',
  credentials: 'include',
  body: JSON.stringify({ title: 'New post' })
})
  .then(res => res.body.json())
  .then(data => {
    console.log('Got my JSON', data);
  });

<Fetch
  url="/posts/2"
  method="PATCH"
  credentials="include"
  body={JSON.stringify({ title: 'New post' })}>
  {({ data }) => {
    console.log('Got my JSON', data);
    return null;
  }}
</Fetch>

Only string request bodies are supported

For now, you may only pass strings as the request body. This is due to the fact that we need to build a request key for request deduplication and response caching.

In the future, we plan to add support for additional request body types.

Aborting requests

When aborting fetch(), you will typically do the following:

1. Create an AbortController object
2. Pass the AbortSignal object into fetch

This system does not work with <Fetch/>, because it would be tedious for you to create a new AbortController anytime the component was going to make a new request.

It is on our roadmap to provide a great story around aborting requests. For more, see the guide on aborting requests.