react native无法订阅mercure后端通知

Question

我正在与React Native和Symfony合作开发一个通知系统。我使用docker配置了Mercure，以处理对实时更新的前端订阅：.env文件：

###> symfony/mercure-bundle ###
# See https://symfony.com/doc/current/mercure.html#configuration
MERCURE_PUBLISH_URL=http://mercure.localhost/.well-known/mercure
# The default token is signed with the secret key: !ChangeMe!
MERCURE_JWT_TOKEN=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJtZXJjdXJlIjp7InB1Ymxpc2giOlsiKiJdfX0.9-LscFk3QfdDtZ4nyg6BiH4_qDm6pbYHydURBMsDgEc
###< symfony/mercure-bundle ###

mercure.yaml：

mercure:
    enable_profiler: '%kernel.debug%'
    hubs:
        default:
            url: '%env(MERCURE_PUBLISH_URL)%'
            jwt: '%env(MERCURE_JWT_TOKEN)%'

我在我的React Native应用程序中创建了一个通知组件，并在symfony mercure的官方文档中使用了代码：https://symfony.com/doc/4.3/mercure.html#subscribing Notifications.js代码：

import React, { Component } from 'react';
import { View, Text } from 'react-native';

export default class Notifications extends Component {
    constructor(props) {
        super(props);
        this.state = {
        };
    }

    componentDidMount() {
        const url = new URL('http://mercure.localhost/.well-known/mercure');
        url.searchParams.append('topic', 'http://dev.api.partage-mandats.proprietes-privees.com/mandate_shares/{id}');

        url.searchParams.append('topic', 'http://example.com/books/1');
        const eventSource = new EventSource(url);

        eventSource.onmessage = e => console.log(e);
    }

    render() {
        return (
            <View>
                <Text> Notifications </Text>
            </View>
        );
    }
}

我用Postan进行了测试，得到了有效的响应：

​

我尝试了html文件中的javaScript代码进行测试：

<script type="text/javascript">

const url = new URL('http://mercure.localhost/.well-known/mercure');
url.searchParams.append('topic', 'http://dev.api.partage-mandats.proprietes-privees.com/mandate_shares/{id}');

url.searchParams.append('topic', 'http://example.com/books/1');
const eventSource = new EventSource(url);

eventSource.onmessage = e => console.log(e); 
</script>
</html>

当我用Postman运行request时，我得到了一个实时响应：

我的问题是URL、searchParams和eventSource与react native不兼容。如何将此javaScript代码转换为react本机有效代码？我试着安装了一些库:什么is url，buffer，react-native-event-source，我现在的代码是：

import React, { Component } from 'react';
import { View, Text } from 'react-native';

import { URL, URLSearchParams } from 'whatwg-url';
import { Buffer } from 'buffer';
import RNEventSource from 'react-native-event-source';

export default class Notifications extends Component {
  constructor(props) {
    super(props);
    this.state = {
    };
  }

  componentDidMount() {
    global.Buffer = Buffer;
    global.URL = URL;
    global.URLSearchParams = URLSearchParams;
    global.EventSource = RNEventSource;

    const url = new global.URL('http://mercure.localhost/.well-known/mercure');
    url.global.URLSearchParams.append('topic', 'http://dev.api.partage-mandats.proprietes-privees.com/mandate_shares/{id}');

    url.global.URLSearchParams.append('topic', 'http://example.com/books/1');
    const eventSource = new global.EventSource(url);

    eventSource.onmessage = e => console.log(e); 
  }

  render() {
    return (
      <View>
        <Text> Notifications </Text>
      </View>
    );
  }
}

我得到这个错误:未定义的不是一个对象(计算'url.global.URLSearchParams')

Answer 1

我修复了这个问题，它是关于发布url的，我不能使用本地url，所以我创建了一个主机，并像这样配置url：

http://mercure.preprod.oryx-immobilier.com/.well-known/mercure

现在我可以从后台接收实时响应

Answer 2

你可以像下面这样用->代替URLSearchparams

const url = `http://blablabla.com/?topic=<your_topic1>&