Skip to main content

GQLEndpoint

extends

GQLEndpoint extends Endpoint

Fetch Lifecycle​

GQLEndpoint adds to Endpoint by providing customizations for a provided fetch method.

  1. Prepare fetch
    1. url
    2. getRequestInit()
  2. Perform fetch
    1. fetchResponse()
    2. parseResponse()
    3. process()
fetch implementation for GQLEndpoint
async function fetch(variables) {
  return this.fetchResponse(this.url, this.getRequestInit(variables)).then(
    res => this.process(res, variables),
  );
}

Prepare Fetch​

Members double as options (second constructor arg). While none are required, the first few have defaults.

url: string​

GraphQL uses one url for all operations.

getRequestInit(body): RequestInit​

Prepares RequestInit used in fetch. This is sent to fetchResponse

getQuery(variables): string​

Prepare the query, to be sent as part of the body payload.

getHeaders(headers: HeadersInit): HeadersInit​

Called by getRequestInit to determine HTTP Headers

This is often useful for authentication

warning

Don't use hooks here.

Handle fetch​

fetchResponse(input, init): Promise​

Performs the fetch call

parseResponse(response): Promise​

Takes the Response and parses via .text() or .json()

process(value, ...args): any​

Perform any transforms with the parsed result. Defaults to identity function.

Endpoint Life-Cycles​

schema: Schema​

Declarative definition of how to process responses

Not providing this option means no entities will be extracted.

import { GQLEntity, GQLEndpoint } from '@data-client/graphql';
const gql = new GQLEndpoint('https://nosy-baritone.glitch.me');

class User extends GQLEntity {
  username = '';
}

export const getUser = gql.query(
  (v: { name: string }) => `query GetUser($name: String!) {
    user(name: $name) {
      id
      name
      email
    }
  }`,
  { user: User },
);

dataExpiryLength?: number​

Custom data cache lifetime for the fetched resource. Will override the value set in NetworkManager.

Learn more about expiry time

errorExpiryLength?: number​

Custom data error lifetime for the fetched resource. Will override the value set in NetworkManager.

errorPolicy?: (error: any) => 'soft' | undefined​

'soft' will use stale data (if exists) in case of error; undefined or not providing option will result in error.

Learn more about errorPolicy

errorPolicy(error) {
  return error.status >= 500 ? 'soft' : undefined;
}

invalidIfStale: boolean​

Indicates stale data should be considered unusable and thus not be returned from the cache. This means that useSuspense() will suspend when data is stale even if it already exists in cache.

pollFrequency: number​

Frequency in millisecond to poll at. Requires using useSubscription() or useLive() to have an effect.

getOptimisticResponse: (snap, ...args) => fakePayload​

When provided, any fetches with this endpoint will behave as though the fakePayload return value from this function was a succesful network response. When the actual fetch completes (regardless of failure or success), the optimistic update will be replaced with the actual network response.

update(normalizedResponseOfThis, ...args) => ({ [endpointKey]: (normalizedResponseOfEndpointToUpdate) => updatedNormalizedResponse) })​

UpdateType.ts
type UpdateFunction<
  Source extends EndpointInterface,
  Updaters extends Record<string, any> = Record<string, any>,
> = (
  source: ResultEntry<Source>,
  ...args: Parameters<Source>
) => { [K in keyof Updaters]: (result: Updaters[K]) => Updaters[K] };

extend(options): Endpoint​

Can be used to further customize the endpoint definition

const gql = new GQLEndpoint('https://nosy-baritone.glitch.me');

const authGQL = gql.extend({
  getHeaders(headers: HeadersInit): HeadersInit {
    return {
      ...headers,
      'Access-Token': getAuth(),
    };
  },
});