@jumpn/absinthe-phoenix-socket

@jumpn/absinthe-phoenix-socket

Absinthe Phoenix Socket

• Features
• Installation
  • Using npm
  • Using yarn
• Types
• API
  • create
  • discard
  • observe
  • send
  • unobserve
• 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.

• Reconnect channel on connection lost

  Phoenix socket reconnects on connection lost but it doesn't rejoin to the channel automatically, we do.

• Handle pending operations on connection lost

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

• 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 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 @jumpn/absinthe-phoenix-socket

Using yarn

$ yarn add @jumpn/absinthe-phoenix-socket

Types

type Event = "Abort" | "Error" | "Start" | "Stop" | "Value";

type Observer<Value> = {
  onAbort: (error: Error) => any,
  onError: (error: Error) => any,
  onStart: () => any,
  onValue: (value: Value) => any
};

type Notifier<Result> = {
  observers: Array<Observer<Result>>,
  operationType: GqlOperationType,
  request: GqlRequest<*>,
  subscriptionId?: string
};

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

API

create

Creates an Absinthe Socket using the given Phoenix Socket instance

Parameters

• phoenixSocket PhoenixSocket

Examples

import * as AbsintheSocket from "@jumpn/absinthe-phoenix-socket";
import {Socket as PhoenixSocket} from "phoenix";

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

Returns AbsintheSocket

discard

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

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<any>

Examples

import * as AbsintheSocket from "@jumpn/absinthe-phoenix-socket";

AbsintheSocket.discard(absintheSocket, notifier);

Returns AbsintheSocket

observe

Observes given notifier using the provided observer

Parameters

• absintheSocket AbsintheSocket
• notifier Notifier<Value>
• observer Observer<Value>

Examples

import AbsintheSocket from "@jumpn/absinthe-phoenix-socket"

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

const updatedNotifier = AbsintheSocket.observe(absintheSocket, notifier, {
  onAbort: logEvent("abort"),
  onError: logEvent("error"),
  onStart: logEvent("open"),
  onValue: logEvent("next")
});

Returns AbsintheSocket

send

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

Parameters

• absintheSocket AbsintheSocket
• request GqlRequest<any>

Examples

import * as AbsintheSocket from "@jumpn/absinthe-phoenix-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 = AbsintheSocket.send(absintheSocket, {
  operation,
  variables: {userId: 10}
});

Returns Notifier<any>

unobserve

Detaches observer from notifier

Parameters

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

Examples

import * as AbsintheSocket from "@jumpn/absinthe-phoenix-socket";

AbsintheSocket.unobserve(absintheSocket, notifier, observer);

Returns AbsintheSocket

License

MIT :copyright: Jumpn Limited / Mauro Titimoli ([e-mail])