@absinthe/socket

Absinthe Socket

• Features
• Installation

- Using npm - Using yarn

• Types
• API

- cancel

- [Parameters](#parameters)
- [Examples](#examples)

- create

- [Parameters](#parameters-1)
- [Examples](#examples-1)

- observe

- [Parameters](#parameters-2)
- [Examples](#examples-2)

- send

- [Parameters](#parameters-3)
- [Examples](#examples-3)

- toObservable

- [Parameters](#parameters-4)
- [Examples](#examples-4)

- unobserve

- [Parameters](#parameters-5)
- [Examples](#examples-5)

- unobserveOrCancel

- [Parameters](#parameters-6)
- [Examples](#examples-6)

• License

Features

• Immutable functional API

> All received and returned objects with the exception of AbsintheSocket
>   instances (there are plans to make this immutable too) are treated in an
>   immutable way. Objects have no methods and instead we provide independant
>   stateless functions to interact with them.

• Lazy connect / join

> If provided phoenix socket instance is not connected, then instead of
>   connecting at creation time, connection will be established on the next
>   invocation of [send](#send).

• Handle pending operations on connection lost

> Pending mutations will be aborted, queries will be resent, and subscriptions
>   reestablished.

• Cancellable requests

> Calling [cancel](#cancel) removes given notifier from absintheSocket instance
>   and sends a Cancel event to all its observers and unsubscribes in case it
>   holds a subscription request.

• Operations deduplication

> If an already sent request is given to [send](#send), then instead of sending
>   it again, the notifier associated with it will be returned.

• Observer support of recoverable errors

> Since connection lost is handled, then two events needs to exist to represent
>   this fact: Error (recoverable), Abort (unrecoverable).

• Multiple observers per request

> Calling [send](#send) returns a notifier which allows attaching any number of
>   observers that will be notified when result arrives.

• Observer interaction depending on operation type

> For the case of subscriptions, _Start_ event is dispatched when the
>   subscription is established, while for the other types
>   (queries and mutations), when the request is sent.

Installation

Using npm

$ npm install --save phoenix @absinthe/socket

Using yarn

$ yarn add phoenix @absinthe/socket

Types

type RequestStatus = "canceled" | "canceling" | "pending" | "sent" | "sending";

// from @jumpn/utils-graphql
type GqlRequest<Variables: void | Object = void> = {
  operation: string,
  variables?: Variables
};

// from @jumpn/utils-graphql
type GqlResponse<Data> = {
  data?: Data,
  errors?: Array<GqlError>
};

// from @jumpn/utils-graphql
type GqlOperationType = "mutation" | "query" | "subscription";

type Observer<Result, Variables: void | Object = void> = {|
  onAbort?: (error: Error) => any,
  onCancel?: () => any,
  onError?: (error: Error) => any,
  onStart?: (notifier: Notifier<Result, Variables>) => any,
  onResult?: (result: Result) => any
|};

type Notifier<Result, Variables: void | Object = void> = {|
  activeObservers: $ReadOnlyArray<Observer<Result, Variables>>,
  canceledObservers: $ReadOnlyArray<Observer<Result, Variables>>,
  isActive: boolean,
  operationType: GqlOperationType,
  request: GqlRequest<Variables>,
  requestStatus: RequestStatus,
  subscriptionId?: string
|};

type AbsintheSocket = {|
  channel: Channel,
  channelJoinCreated: boolean,
  notifiers: Array<Notifier<any>>,
  phoenixSocket: PhoenixSocket
|};

API

cancel

Cancels a notifier sending a Cancel event to all its observers and unsubscribing in case it holds a subscription request

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<any, any>

Examples

import * as withAbsintheSocket from "@absinthe/socket";

withAbsintheSocket.cancel(absintheSocket, notifier);

Returns AbsintheSocket

create

Creates an Absinthe Socket using the given Phoenix Socket instance

Parameters

• phoenixSocket PhoenixSocket

Examples

import * as withAbsintheSocket from "@absinthe/socket";
import {Socket as PhoenixSocket} from "phoenix";

const absintheSocket = withAbsintheSocket.create(
  new PhoenixSocket("ws://localhost:4000/socket")
);

Returns AbsintheSocket

observe

Observes given notifier using the provided observer

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<Result, Variables>
• observer Observer<Result, Variables>

Examples

import * as withAbsintheSocket from "@absinthe/socket"

const logEvent = eventName => (...args) => console.log(eventName, ...args);

const updatedNotifier = withAbsintheSocket.observe(absintheSocket, notifier, {
  onAbort: logEvent("abort"),
  onError: logEvent("error"),
  onStart: logEvent("open"),
  onResult: logEvent("result")
});

send

Sends given request and returns an object (notifier) to track its progress (see observe function)

Parameters

• absintheSocket AbsintheSocket
• request GqlRequest<Variables>

Examples

import * as withAbsintheSocket from "@absinthe/socket";

const operation = `
  subscription userSubscription($userId: ID!) {
    user(userId: $userId) {
      id
      name
    }
  }
`;

// This example uses a subscription, but the functionallity is the same for
// all operation types (queries, mutations and subscriptions)

const notifier = withAbsintheSocket.send(absintheSocket, {
  operation,
  variables: {userId: 10}
});

Returns Notifier<Result, Variables>

toObservable

Creates an Observable that will follow the given notifier

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<Result, Variables>
• options Object? (optional, default {})

-   `options.unsubscribe` **function (): [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined)?** 
-   `options.onError` **function (error: [Error](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error)): [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined)?** 
-   `options.onStart` **function (notifier: Notifier<Result, Variables>): [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined)?** 
-   `options.handlers` **...any** 

Examples

import * as withAbsintheSocket from "@absinthe/socket";

const unobserveOrCancelIfNeeded = (absintheSocket, notifier, observer) => {
  if (notifier && observer) {
    withAbsintheSocket.unobserveOrCancel(absintheSocket, notifier, observer);
  }
};

const logEvent = eventName => (...args) => console.log(eventName, ...args);

const observable = withAbsintheSocket.toObservable(absintheSocket, notifier, {
  onError: logEvent("error"),
  onStart: logEvent("open"),
  unsubscribe: unobserveOrCancelIfNeeded
});

Returns Observable

unobserve

Detaches observer from notifier

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<any, any>
• observer Observer<any, any>

Examples

import * as withAbsintheSocket from "@absinthe/socket";

withAbsintheSocket.unobserve(absintheSocket, notifier, observer);

Returns AbsintheSocket

unobserveOrCancel

Cancels notifier if there are no more observers apart from the one given, or detaches given observer from notifier otherwise

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<Result, Variables>
• observer Observer<Result, Variables>

Examples

import * as withAbsintheSocket from "@absinthe/socket";

withAbsintheSocket.unobserve(absintheSocket, notifier, observer);

License

MIT :copyright: Jumpn Limited.