@conjecto/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

Apollo Boost doesn’t allow link customization; if you are using it migrate to a manual Apollo Client setup.

Apollo Client can only have 1 “terminating” Apollo Link that sends the GraphQL requests; if one such as apollo-link-http is already setup, remove it.

Initialize the client with a terminating 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

const { useMutation } = require('@apollo/react-hooks');
const gql = require('graphql-tag');

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

const { useMutation } = require('@apollo/react-hooks');
const gql = require('graphql-tag');

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

const { useMutation } = require('@apollo/react-hooks');
const gql = require('graphql-tag');

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 v10+
• Browsers > 0.5%, not OperaMini all, not dead
• React Native

Consider polyfilling:

• Promise
• fetch
• FormData

API

Table of contents

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

class ReactNativeFile

Used to mark React Native File substitutes as it’s too risky to assume all objects with uri, type and name properties are extractable files.

Parameter	Type	Description
file	ReactNativeFileSubstitute	A React Native File substitute.

See

• extract-files ReactNativeFile docs.

Examples

A React Native file that can be used in query or mutation variables.

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

const file = new ReactNativeFile({
  uri: uriFromCameraRoll,
  name: 'a.jpg',
  type: 'image/jpeg',
});

---

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.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

A basic Apollo Client setup.

const { ApolloClient } = require('apollo-client');
const { InMemoryCache } = require('apollo-cache-inmemory');
const { createUploadLink } = require('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.

---

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.

---

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.

const { isExtractableFile } = require('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 requests with Chrome dev tools interferes with the React Native FormData implementation, causing 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.

{
  uri: uriFromCameraRoll,
  name: 'a.jpg',
  type: 'image/jpeg'
}