graphql - Apollo Graphql : Avoid loading indicator during refetch

Question

我有以下 apollo-graphql 客户端代码，其中我每 30 秒触发一次 graphql 查询并获取数据。

import React, { Component } from 'react';
import { gql, graphql } from 'react-apollo';
import _ from 'underscore';

class Test extends Component {

    render() {
        if (this.props.TestData.loading) {
            return <div>Loading...</div>
        }

        if (this.props.TestData.error && this.props.TestData.error !== null) {
            return <div>Error...</div>
        }

        // Iterate through the this.props.TestData.getTestData and build the Table of data here
        return (
            <table>
                _.map(this.props.TestData.getTestData.testList, (test) => {
                    <tr>
                        <td>{test.testName}</td>
                        <td>{test.status}</td>
                    </tr>
                })
            </table>
        );
    }

}

const TestQuery = gql`
    query TestQuery() {
        getTestData() {
            testList {
                testName
                status
            }
        }
    }
`;

const options = () => ({
    pollInterval: 30000,
});

const withTestData = graphql(TestQuery, { 
    name: 'TestData',
    options, 
});

export default withTestData(Test);

我面临的问题是每隔 30 秒我就会看到 Loading... 因为查询被重新触发。我希望 Loading... 仅在页面启动时显示，此后应该可以顺利更新，我不想显示 Loading...给用户的指标。不确定如何实现这一目标。

Answer 1

我知道文档建议使用 data.loading，但在大多数情况下检查查询结果是否为 null 也同样有效:

// Should probably check this first. If you error out, usually your data will be
// undefined, which means putting this later would result in it never getting
// called. Also checking if it's not-null is a bit redundant :)
if (this.props.TestData.error) return <div>Error...</div>

// `testList` will only be undefined during the initial fetch
// or if the query errors out
if (!this.props.TestData.getTestData) return <div>Loading...</div>

// Render the component as normal
return <table>...</table>

请记住，GraphQL 可能会返回一些错误并且数据仍会返回。这意味着在生产环境中，您可能需要更强大的错误处理行为，这种行为不一定会在出现任何错误时阻止页面呈现。