!Apollo upload logo

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:

``shell
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.

$3

`jsx
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 ;
}
`

$3

`jsx
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 ;
}
`

$3

`jsx
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 ;
}
`

Support

- Node.js v10+
- Browsers > 0.5%, not OperaMini all, not dead
- React Native

Consider polyfilling:

- Promise
- fetch
- FormData

API

$3

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

$3

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._

> `js
> const { ReactNativeFile } = require('apollo-upload-client');
>
> const file = new ReactNativeFile({
> uri: uriFromCameraRoll,
> name: 'a.jpg',
> type: 'image/jpeg',
> });
> `

---

$3

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._

> `js
> 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(),
> });
> `

---

$3

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. |

---

$3

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.

---

$3

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._

> `js
> const { isExtractableFile } = require('apollo-upload-client');
>
> const isExtractableFileEnhanced = (value) =>
> isExtractableFile(value) ||
> (typeof CustomFile !== 'undefined' && value instanceof CustomFile);
> `

---

$3

GraphQL request fetch options.

Type: object

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

#### See

- Polyfillable fetch options.

---

$3

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.

---

$3

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._

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