Request Policy Exchange

The @urql/exchange-request-policy package contains an addon requestPolicyExchange for urql that may be used to upgrade Operations' Request Policies on a time-to-live basis.

This exchange will conditionally upgrade cache-first and cache-only operations to use cache-and-network, so that the client gets an opportunity to update its cached data, when the operation hasn't been seen within the given ttl time. This is often preferable to setting the default policy to cache-and-network to avoid an unnecessarily high amount of requests to be sent to the API when switching pages.

Installation and Setup

First install @urql/exchange-request-policy alongside urql:

yarn add @urql/exchange-request-policy
# or
npm install --save @urql/exchange-request-policy

Then add it to your Client, preferably after the dedupExchange but in front of any asynchronous exchanges, like the fetchExchang:

import { createClient, dedupExchange, cacheExchange, fetchExchange } from 'urql';
import { requestPolicyExchange } from '@urql/exchange-request-policy';

const client = createClient({
  url: '/graphql',
  exchanges: [
    dedupExchange,
    requestPolicyExchange({
      /* config */
    }),
    cacheExchange,
    fetchExchange,
  ],
});

Options

Option	Description
`ttl`	The "time-to-live" until an `Operation` will be upgraded to the `cache-and-network` policy in milliseconds. By default 5 minutes is set.
`shouldUpgrade`	An optional function that receives an `Operation` as the only argument and may return `true` or `false` depending on whether an operation should be upgraded. This can be used to filter out operations that should never be upgraded to `cache-and-network`.