如何在无client实例的Apollo Client Hooks中终止待处理请求？

Great question! When you're working with Apollo Client Hooks and don't have direct access to a client instance, there are a couple of reliable ways to cancel pending requests—let's break them down:

1. 获取Client实例后调用stop() #

Apollo Client provides the useApolloClient Hook specifically for cases where you need access to the client instance in a component using Hooks. Once you have that instance, you can call client.stop() to cancel all pending requests (queries and mutations alike).

Here's a quick example:

import { useApolloClient } from '@apollo/client';

function RequestCanceler() {
  const client = useApolloClient();

  const cancelAllPendingRequests = () => {
    client.stop();
    console.log('All pending requests have been canceled');
  };

  return (
    <button onClick={cancelAllPendingRequests}>
      Cancel All Pending Requests
    </button>
  );
}

2. 细粒度控制：终止单个特定请求 #

If you don't want to cancel every pending request and only need to target one specific query, you have two solid options depending on how you're triggering the request:

Option A: Use useLazyQuery's built-in cancel function #

useLazyQuery returns a cancel function as part of its result object, which lets you cancel the specific request initiated by that hook. Perfect for one-off, user-triggered queries:

import { useLazyQuery } from '@apollo/client';
import { GET_USER_DATA } from './your-queries';

function UserDataLoader() {
  const [fetchUserData, { loading, data, cancel }] = useLazyQuery(GET_USER_DATA);

  return (
    <div>
      <button onClick={() => fetchUserData({ variables: { userId: 123 } })}>
        Load User Data
      </button>
      {loading && (
        <button onClick={cancel} style={{ marginLeft: '10px' }}>
          Cancel Load
        </button>
      )}
    </div>
  );
}

Option B: Toggle the skip flag in useQuery #

For automatically triggered queries (using useQuery without lazy loading), you can use the skip option. Setting skip to true will immediately cancel the pending request, and you can reset it later if needed:

import { useState } from 'react';
import { useQuery } from '@apollo/client';
import { GET_PRODUCTS } from './your-queries';

function ProductList() {
  const [skipQuery, setSkipQuery] = useState(false);
  const { loading, data } = useQuery(GET_PRODUCTS, {
    skip: skipQuery,
    onCompleted: () => setSkipQuery(false), // Reset skip once request finishes
  });

  return (
    <div>
      {loading && (
        <button onClick={() => setSkipQuery(true)}>
          Cancel Product Load
        </button>
      )}
      {/* Render product data here */}
    </div>
  );
}

A quick note: client.stop() is a blunt instrument—it cancels everything. If you need precision, go with the single-request methods above.

内容的提问来源于stack exchange，提问作者Dude