@nexusapp/apollo-upload-client

apollo-upload-client

A terminating Apollo Link for Apollo Client that allows FileList, File, Blob or ReactNativeFile instances within query or mutation variables and sends GraphQL multipart requests.

Setup

Install with npm:

npm install apollo-upload-client

Remove any uri, credentials, or headers options from the ApolloClient constructor.

Apollo Client can only have 1 terminating Apollo Link that sends the GraphQL requests; if one such as HttpLink is already setup, remove it.

Initialize the client with a terminating Apollo Link using createUploadLink.

Also ensure the GraphQL server implements the GraphQL multipart request spec and that uploads are handled correctly in resolvers.

Usage

Use FileList, File, Blob or ReactNativeFile instances anywhere within query or mutation variables to send a GraphQL multipart request.

See also the example API and client.

FileList

import { gql, useMutation } from '@apollo/client';

const MUTATION = gql`
  mutation ($files: [Upload!]!) {
    uploadFiles(files: $files) {
      success
    }
  }
`;

function UploadFiles() {
  const [mutate] = useMutation(MUTATION);

  function onChange({ target: { validity, files } }) {
    if (validity.valid) mutate({ variables: { files } });
  }

  return <input type="file" multiple required onChange={onChange} />;
}

File

import { gql, useMutation } from '@apollo/client';

const MUTATION = gql`
  mutation ($file: Upload!) {
    uploadFile(file: $file) {
      success
    }
  }
`;

function UploadFile() {
  const [mutate] = useMutation(MUTATION);

  function onChange({
    target: {
      validity,
      files: [file],
    },
  }) {
    if (validity.valid) mutate({ variables: { file } });
  }

  return <input type="file" required onChange={onChange} />;
}

Blob

import { gql, useMutation } from '@apollo/client';

const MUTATION = gql`
  mutation ($file: Upload!) {
    uploadFile(file: $file) {
      success
    }
  }
`;

function UploadFile() {
  const [mutate] = useMutation(MUTATION);

  function onChange({ target: { validity, value } }) {
    if (validity.valid) {
      const file = new Blob([value], { type: 'text/plain' });

      // Optional, defaults to `blob`.
      file.name = 'text.txt';

      mutate({ variables: { file } });
    }
  }

  return <input type="text" required onChange={onChange} />;
}

Support

• Node.js ^10.17.0 || ^12.0.0 || >= 13.7.0
• Browsers > 0.5%, not OperaMini all, not dead
• React Native

Consider polyfilling:

• Promise
• fetch
• FormData

API

Table of contents

• function createUploadLink
• function formDataAppendFile
• function isExtractableFile
• type ExtractableFileMatcher
• type FetchOptions
• type FormDataFileAppender
• type ReactNativeFileSubstitute

function createUploadLink

Creates a terminating Apollo Link capable of file uploads.

The link matches and extracts files in the GraphQL operation. If there are files it uses a FormData instance as the fetch options.body to make a GraphQL multipart request, otherwise it sends a regular POST request.

Some of the options are similar to the createHttpLink options.

Parameter	Type	Description
options	object	Options.
options.uri	string? = /graphql	GraphQL endpoint URI.
options.useGETForQueries	boolean?	Should GET be used to fetch queries, if there are no files to upload.
options.isExtractableFile	ExtractableFileMatcher? = isExtractableFile	Customizes how files are matched in the GraphQL operation for extraction.
options.FormData	class?	FormData implementation to use, defaulting to the FormData global.
options.formDataAppendFile	FormDataFileAppender? = formDataAppendFile	Customizes how extracted files are appended to the FormData instance.
options.fetch	Function?	fetch implementation to use, defaulting to the fetch global.
options.fetchOptions	FetchOptions?	fetch options; overridden by upload requirements.
options.credentials	string?	Overrides options.fetchOptions.credentials.
options.headers	object?	Merges with and overrides options.fetchOptions.headers.
options.includeExtensions	boolean? = false	Toggles sending extensions fields to the GraphQL server.

Returns: ApolloLink — A terminating Apollo Link capable of file uploads.

See

• GraphQL multipart request spec.
• apollo-link on GitHub.

Examples

Ways to import.

import { createUploadLink } from 'apollo-upload-client';

import createUploadLink from 'apollo-upload-client/public/createUploadLink.js';

Ways to require.

const { createUploadLink } = require('apollo-upload-client');

const createUploadLink = require('apollo-upload-client/public/createUploadLink');

A basic Apollo Client setup.

import { ApolloClient, InMemoryCache } from '@apollo/client';
import { createUploadLink } from 'apollo-upload-client';

const client = new ApolloClient({
  cache: new InMemoryCache(),
  link: createUploadLink(),
});

---

function formDataAppendFile

The default implementation for createUploadLink options.formDataAppendFile that uses the standard FormData.append method.

Type: FormDataFileAppender

Parameter	Type	Description
formData	FormData	FormData instance to append the specified file to.
fieldName	string	Field name for the file.
file	*	File to append.

Examples

Ways to import.

import { formDataAppendFile } from 'apollo-upload-client';

import formDataAppendFile from 'apollo-upload-client/public/formDataAppendFile.js';

Ways to require.

const { formDataAppendFile } = require('apollo-upload-client');

const formDataAppendFile = require('apollo-upload-client/public/formDataAppendFile');

---

function isExtractableFile

The default implementation for createUploadLink options.isExtractableFile.

Type: ExtractableFileMatcher

Parameter	Type	Description
value	*	Value to check.

Returns: boolean — Is the value an extractable file.

See

• extract-files isExtractableFile docs.

Examples

Ways to import.

import { isExtractableFile } from 'apollo-upload-client';

import isExtractableFile from 'apollo-upload-client/public/isExtractableFile.js';

Ways to require.

const { isExtractableFile } = require('apollo-upload-client');

const isExtractableFile = require('apollo-upload-client/public/isExtractableFile');

---

type ExtractableFileMatcher

A function that checks if a value is an extractable file.

Type: Function

Parameter	Type	Description
value	*	Value to check.

Returns: boolean — Is the value an extractable file.

See

• isExtractableFile has this type.

Examples

How to check for the default exactable files, as well as a custom type of file.

import { isExtractableFile } from 'apollo-upload-client';

const isExtractableFileEnhanced = (value) =>
  isExtractableFile(value) ||
  (typeof CustomFile !== 'undefined' && value instanceof CustomFile);

---

type FetchOptions

GraphQL request fetch options.

Type: object

Property	Type	Description
headers	object	HTTP request headers.
credentials	string?	Authentication credentials mode.

See

• Polyfillable fetch options.

---

type FormDataFileAppender

Appends a file extracted from the GraphQL operation to the FormData instance used as the fetch options.body for the GraphQL multipart request.

Parameter	Type	Description
formData	FormData	FormData instance to append the specified file to.
fieldName	string	Field name for the file.
file	*	File to append. The file type depends on what the ExtractableFileMatcher extracts.

See

• formDataAppendFile has this type.
• createUploadLink accepts this type in options.formDataAppendFile.

---

type ReactNativeFileSubstitute

A React Native File substitute.

Be aware that inspecting network traffic with buggy versions of dev tools such as Flipper can interfere with the React Native FormData implementation, causing multipart requests to have network errors.

Type: object

Property	Type	Description
uri	string	Filesystem path.
name	string?	File name.
type	string?	File content type. Some environments (particularly Android) require a valid MIME type; Expo ImageResult.type is unreliable as it can be just image.

See

• extract-files ReactNativeFileSubstitute docs.
• React Native FormData polyfill source.

Examples

A camera roll file.

const fileSubstitute = {
  uri: uriFromCameraRoll,
  name: 'a.jpg',
  type: 'image/jpeg',
};