在Apollo Client中,可以使用Apollo Link State库来管理本地状态。以下是一个示例解决方法,用于在已登录查询时管理本地状态:
npm install apollo-link apollo-link-state apollo-cache-inmemory graphql-tag
// localState.graphql
import gql from 'graphql-tag';
export const GET_LOGIN_STATUS = gql`
query GetLoginStatus {
isLoggedIn @client
}
`;
export const SET_LOGIN_STATUS = gql`
mutation SetLoginStatus($isLoggedIn: Boolean!) {
setLoginStatus(isLoggedIn: $isLoggedIn) @client
}
`;
// resolvers.js
import { GET_LOGIN_STATUS, SET_LOGIN_STATUS } from './localState.graphql';
export const resolvers = {
Query: {
isLoggedIn: (_root, _args, { cache }) => {
const { isLoggedIn } = cache.readQuery({ query: GET_LOGIN_STATUS });
return isLoggedIn;
},
},
Mutation: {
setLoginStatus: (_root, { isLoggedIn }, { cache }) => {
cache.writeQuery({
query: GET_LOGIN_STATUS,
data: { isLoggedIn },
});
return null;
},
},
};
import { ApolloClient } from 'apollo-client';
import { HttpLink } from 'apollo-link-http';
import { InMemoryCache } from 'apollo-cache-inmemory';
import { ApolloLink } from 'apollo-link';
import { withClientState } from 'apollo-link-state';
import { resolvers } from './resolvers';
const cache = new InMemoryCache();
const stateLink = withClientState({
cache,
resolvers,
});
const httpLink = new HttpLink({
uri: 'http://your-graphql-endpoint',
});
const client = new ApolloClient({
cache,
link: ApolloLink.from([stateLink, httpLink]),
});
import React from 'react';
import { useQuery, useMutation } from '@apollo/react-hooks';
import { GET_LOGIN_STATUS, SET_LOGIN_STATUS } from './localState.graphql';
const MyComponent = () => {
const { data } = useQuery(GET_LOGIN_STATUS);
const [setLoginStatus] = useMutation(SET_LOGIN_STATUS);
const handleLogin = () => {
setLoginStatus({ variables: { isLoggedIn: true } });
};
const handleLogout = () => {
setLoginStatus({ variables: { isLoggedIn: false } });
};
return (
{data.isLoggedIn ? (
) : (
)}
);
};
export default MyComponent;
以上示例展示了如何使用Apollo Client的本地状态来管理已登录查询。通过使用Apollo Link State和本地状态查询和突变,可以轻松地管理和更新本地状态。