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，自从查询被重新触发后，我每隔30秒就会看到Loading...。我希望Loading...仅在页面启动时显示，此后它应该是平滑更新，我不想向用户显示Loading...指示符。不知道如何实现这一目标。

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也是如此：

// 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仍然可以返回数据。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，如果存在任何错误，则不一定会阻止页面呈现。

Apollo Graphql：避免在重新获取期间加载指标

1 个答案: