SubscriptionAction

SubscriptionAction is a type which defines the structure of subscription actions. Like all Redux actions it obviously has a type property. Also it must have subscription property and might have meta property.

subscription

This is mandatory key in any subscription action.

const onBookAdded = () => ({
  type: 'ON_BOOK_ADDED',
  subscription: {
    type: 'ON_BOOK_ADDED',
  },
});

Just pass it whatever your websocket server needs to start the subscription. Then, it will be automatically send to your server. If your server doesn't need any message to start the subscription, just pass null.

meta

While subscription key is mandatory, meta is optional. As an example, let's add a meta property to ON_BOOK_ADDED action:

const onBookAdded = id => ({
  type: 'ON_BOOK_ADDED',
  subscription: {
    type: 'ON_BOOK_ADDED',
  },
  meta: {
    requestKey: id,
  },
});

which would allow having multiple and independent subscriptions for ON_BOOK_ADDED, per id.

Below you can see the list of all possible meta options:

getData: data => transformedData

A function which is called on received messages, which allows you to transform data received from server.

requestKey: string

Allows you to have multiple independent subscriptions for the same type, per requestKey.

normalize: boolean

Automatically normalize data from server messages. More information in automatic normalisation tutorial.

onMessage: (data, message, store) => void

Function which will be called on each received message from the server. It can be used for side-effects.

mutations

An object to instruct a subscription how to update queries data. Its keys are just query types and values are update functions, for example for ON_BOOK_ADDED subscription we could have:

mutations: {
  FETCH_BOOKS: (data, subscriptionData) => [...data, subscriptionData.addedBook],
}