Apollo 3 分页与字段策略

有人可以提供使用 Apollo Client 3.0 字段策略实现分页的示例吗？我一直在遵循文档中的示例来实现无限滚动，但在我的控制台中我收到以下警告：

The updateQuery callback for fetchMore is deprecated, and will be removed
in the next major version of Apollo Client.

Please convert updateQuery functions to field policies with appropriate
read and merge functions, or use/adapt a helper function (such as
concatPagination, offsetLimitPagination, or relayStylePagination) from
@apollo/client/utilities.

The field policy system handles pagination more effectively than a
hand-written updateQuery function, and you only need to define the policy
once, rather than every time you call fetchMore.

我对 Apollo 相当陌生，我真的不知道如何以 3.0 的方式做到这一点。我希望能举一些例子来更好地理解。

这是我当前的代码：

import React from "react";
import { useGetUsersQuery } from "./generated/graphql";
import { Waypoint } from "react-waypoint";

const App = () => {
  const { data, loading, error, fetchMore } = useGetUsersQuery({
    variables: { limit: 20, offset: 0 },
  });

  if (loading) return <div>Loading...</div>;
  if (error) return <div>Error</div>;

  return (
    <div className="App">
      {data && data.users && (
        <div>
          {data.users.map((user, i) => {
            return (
              <div key={i} style={{ margin: "20px 0" }}>
                <div>{user.id}</div>
                <div>{user.name}</div>
              </div>
            );
          })}
          <Waypoint
            onEnter={() => {
              fetchMore({
                variables: { offset: data.users.length },
                updateQuery: (prev, { fetchMoreResult }) => {
                  console.log("called");
                  if (!fetchMoreResult) return prev;
                  return Object.assign({}, prev, {
                    users: [...prev.users, fetchMoreResult.users],
                  });
                },
              });
            }}
          />
        </div>
      )}
    </div>
  );
};

export default App;

完全删除 updateQuery 回调函数：

fetchMore({ variables: { offset: data.users.length } });

并将缓存更改为：

import { offsetLimitPagination } from "@apollo/client/utilities";

const cache = new InMemoryCache({
  typePolicies: {
    Query: {
      fields: {
        users: offsetLimitPagination(),
      },
    },
  },
});

所以你在 graphql 中的查询必须有 offset 和 limit 参数。

其他选项有：concatPagination and relayStylePagination

如果需要区分对同一字段的不同请求users前任。输入 keyArg：offsetLimitPagination(["filters"])并使用过滤器 arg 查询您的用户。缓存会单独存储它。

更多信息在正式发布 https://www.apollographql.com/blog/announcing-the-release-of-apollo-client-3-0/