π£ Minimal hooks-first GraphQL client.
- π₯ First-class hooks API
- βοΈ Tiny bundle: only 5.1kB (1.9 gzipped)
- π Full SSR support: see graphql-hooks-ssr
- π Plugin Caching: see graphql-hooks-memcache
- π₯ No more render props hell
- β³ Handle loading and error states with ease
npm install graphql-hooks
or
yarn add graphql-hooks
- Latest 8 & 10 Node releases
- Browsers
> 1%, not dead
Consider polyfilling:
Promise
fetch
. NOTE: A custom implementation can also be provided instead of polyfilling, seeGraphQLClient
First you'll need to create a client and wrap your app with the provider:
import { GraphQLClient, ClientContext } from 'graphql-hooks';
const client = new GraphQLClient({
url: '/graphql'
});
function App() {
return (
<ClientContext.Provider value={client}>
{/* children */}
</ClientContext.Provider>
);
}
Now in your child components you can make use of useQuery
import { useQuery } from 'graphql-hooks';
const HOMEPAGE_QUERY = `query HomePage($limit: Int) {
users(limit: $limit) {
id
name
}
}`;
function MyComponent() {
const { loading, error, data } = useQuery(HOMEPAGE_QUERY, {
variables: {
limit: 10
}
});
if (loading) return 'Loading...';
if (error) return 'Something Bad Happened';
return (
<ul>
{data.users.map(({ id, name }) => (
<li key={id}>{name}</li>
))}
</ul>
);
}
- API
- Guides
Usage:
import { GraphQLClient } from 'graphql-hooks';
const client = new GraphQLClient(config);
config
: Object containing configuration properties
url
(Required): The url to your GraphQL serverssrMode
: Boolean - set totrue
when using on the server for server-side rendering; defaults tofalse
cache
: Object with the following methods:cache.get(key)
cache.set(key, data)
cache.delete(key)
cache.clear()
cache.keys()
getInitialState()
- See graphql-hooks-memcache as a reference implementation
fetch(url, options)
: Fetch implementation - defaults to the globalfetch
APIfetchOptions
: See MDN for info on what options can be passedheaders
: Object, e.g.{ 'My-Header': 'hello' }
logErrors
: Boolean - defaults totrue
onError({ operation, result })
: Custom error handleroperation
: Object withquery
,variables
andoperationName
result
: Object containingerror
,data
,fetchError
,httpError
andgraphqlErrors
client.setHeader(key, value)
: Updatesclient.headers
adding the new header to the existing headersclient.setHeaders(headers)
: Replacesclient.headers
client.logErrorResult({ operation, result })
: Default error logger; useful if you'd like to use it inside your customonError
handlerrequest(operation, options)
: Make a request to your GraphQL server; returning a Promiseoperation
: Object withquery
,variables
andoperationName
options.fetchOptionsOverrides
: Object containing additional fetch options to be added to the default ones passed tonew GraphQLClient(config)
ClientContext
is the result of React.createContext()
- meaning it can be used directly with React's new context API:
Example:
import { ClientContext } from 'graphql-hooks';
<ClientContext.Provider value={client}>
{/* children can now consume the client context */}
</ClientContext.Provider>;
To access the GraphQLClient
instance, call React.useContext(ClientContext)
:
import React, { useContext } from 'react';
import { ClientContext } from 'graphql-hooks';
function MyComponent() {
const client = useContext(ClientContext);
}
Usage:
const state = useQuery(query, [options]);
Example:
import { useQuery } from 'graphql-hooks';
function MyComponent() {
const { loading, error, data } = useQuery(query);
if (loading) return 'Loading...';
if (error) return 'Something bad happened';
return <div>{data.thing}</div>;
}
This is a custom hook that takes care of fetching your query and storing the result in the cache. It won't refetch the query unless query
or options.variables
changes.
query
: Your GraphQL query as a plain stringoptions
: Object with the following optional propertiesvariables
: Object e.g.{ limit: 10 }
operationName
: If your query has multiple operations, pass the name of the operation you wish to execute.useCache
: Boolean - defaults totrue
; cache the query resultskipCache
: Boolean - defaults tofalse
; Iftrue
it will by-pass the cache and fetch, but the result will then be cached for subsequent calls. Note therefetch
function will do this automaticallyssr
: Boolean - defaults totrue
. Set tofalse
if you wish to skip this query during SSRfetchOptionsOverrides
: Object - Specific overrides for this query. See MDN for info on what options can be passedupdateData(previousData, data)
: Function - Custom handler for merging previous & new query results; return value will replacedata
inuseQuery
return valuepreviousData
: Previous GraphQL query orupdateData
resultdata
: New GraphQL query result
const { loading, error, data, refetch, cacheHit, ...errors } = useQuery(QUERY);
loading
: Boolean -true
if the query is in flighterror
: Boolean -true
iffetchError
orhttpError
orgraphQLErrors
has been setdata
: Object - the result of your GraphQL queryrefetch(options)
: Function - useful when refetching the same query after a mutation; NOTE this presetsskipCache=true
& will bypass theoptions.updateData
function that was passed intouseQuery
. You can pass a newupdateData
intorefetch
if necessary.options
: Object - options that will be merged into theoptions
that were passed intouseQuery
(see above).
cacheHit
: Boolean -true
if the query result came from the cache, useful for debuggingfetchError
: Object - Set if an error occured during thefetch
callhttpError
: Object - Set if an error response was returned from the servergraphQLErrors
: Array - Populated if any errors occured whilst resolving the query
Use this when you don't want a query to automactially be fetched, or wish to call a query programmatically.
Usage:
const [queryFn, state] = useManualQuery(query, [options]);
Example:
import { useManualQuery } from 'graphql-hooks'
function MyComponent(props) {
const [fetchUser, { loading, error, data }] = useManualQuery(GET_USER_QUERY, {
variables: { id: props.userId }
})
return (
<div>
<button onClick={fetchUser}>Get User!</button>
{error && <div>Failed to fetch user<div>}
{loading && <div>Loading...</div>}
{data && <div>Hello ${data.user.name}</div>}
</div>
)
}
If you don't know certain options when declaring the useManualQuery
you can also pass the same options to the query function itself when calling it:
import { useManualQuery } from 'graphql-hooks';
function MyComponent(props) {
const [fetchUser] = useManualQuery(GET_USER_QUERY);
const fetchUserThenSomething = async () => {
const user = await fetchUser({
variables: { id: props.userId }
});
return somethingElse();
};
return (
<div>
<button onClick={fetchUserThenSomething}>Get User!</button>
</div>
);
}
Mutations unlike Queries are not cached.
Usage:
const [mutationFn, state] = useMutation(mutation, [options]);
Example:
import { useMutation } from 'graphql-hooks';
const UPDATE_USER_MUTATION = `mutation UpdateUser(id: String!, name: String!) {
updateUser(id: $id, name: $name) {
name
}
}`;
function MyComponent({ id, name }) {
const [updateUser] = useMutation(UPDATE_USER_MUTATION);
const [newName, setNewName] = useState(name);
return (
<div>
<input
type="text"
value={newName}
onChange={e => setNewName(e.target.value)}
/>
<button
onClick={() => updateUser({ variables: { id, name: newName } })}
/>
</div>
);
}
The options
object that can be passed either to useMutation(mutation, options)
or mutationFn(options)
can be set with the following properties:
variables
: Object e.g.{ limit: 10 }
operationName
: If your query has multiple operations, pass the name of the operation you wish to execute.fetchOptionsOverrides
: Object - Specific overrides for this query. See MDN for info on what options can be passed
See graphql-hooks-ssr for an in depth guide.
GraphQL Pagination can be implemented in various ways and it's down to the consumer to decide how to deal with the resulting data from paginated queries. Take the following query as an example of offset pagination:
export const allPostsQuery = `
query allPosts($first: Int!, $skip: Int!) {
allPosts(first: $first, skip: $skip) {
id
title
url
}
_allPostsMeta {
count
}
}
`;
In this query, the $first
variable is used to limit the number of posts that are returned and the $skip
variable is used to determine the offset at which to start. We can use these variables to break up large payloads into smaller chunks, or "pages". We could then choose to display these chunks as distinct pages to the user, or use an infinite loading approach and append each new chunk to the existing list of posts.
Here is an example where we display the paginated queries on separate pages:
import { React, useState } from 'react';
import { useQuery } from 'graphql-hooks';
export default function PostList() {
// set a default offset of 0 to load the first page
const [skipCount, setSkipCount] = useState(0);
const { loading, error, data } = useQuery(allPostsQuery, {
variables: { skip: skipCount, first: 10 }
});
if (error) return <div>There was an error!</div>;
if (loading && !data) return <div>Loading</div>;
const { allPosts, _allPostsMeta } = data;
const areMorePosts = allPosts.length < _allPostsMeta.count;
return (
<section>
<ul>
{allPosts.map(post => (
<li key={post.id}>
<a href={post.url}>{post.title}</a>
</li>
))}
</ul>
<button
// reduce the offset by 10 to fetch the previous page
onClick={() => setSkipCount(skipCount - 10)}
disabled={skipCount === 0}
>
Previous page
</button>
<button
// increase the offset by 10 to fetch the next page
onClick={() => setSkipCount(skipCount + 10)}
disabled={!areMorePosts}
>
Next page
</button>
</section>
);
}
Here is an example where we append each paginated query to the bottom of the current list:
import { React, useState } from 'react';
import { useQuery } from 'graphql-hooks';
// use options.updateData to append the new page of posts to our current list of posts
const updateData = (prevData, data) => ({
...data,
allPosts: [...prevData.allPosts, ...data.allPosts]
});
export default function PostList() {
const [skipCount, setSkipCount] = useState(0);
const { loading, error, data } = useQuery(
allPostsQuery,
{ variables: { skip: skipCount, first: 10 } },
updateData
);
if (error) return <div>There was an error!</div>;
if (loading && !data) return <div>Loading</div>;
const { allPosts, _allPostsMeta } = data;
const areMorePosts = allPosts.length < _allPostsMeta.count;
return (
<section>
<ul>
{allPosts.map(post => (
<li key={post.id}>
<a href={post.url}>{post.title}</a>
</li>
))}
</ul>
{areMorePosts && (
<button
// set the offset to the current number of posts to fetch the next page
onClick={() => setSkipCount(allPosts.length)}
>
Show more
</button>
)}
</section>
);
}
Coming soon!
Coming soon!
Coming soon!
Thanks goes to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome!