Question

我有一个HTTP触发的Firebase函数，该函数使用请求库https://github.com/request/request将HTTP发布到另一个API。日志显示POST请求正在返回正确的数据，但Firebase功能在异步POST返回数据之前就已完成。如何使整体功能等待POST请求？

const functions = require('firebase-functions');
var requestDependency = require('request');

exports.XXXXXXXXXX = functions.https.onRequest((request, response) => {

    var answer = 'testo';
    var jsonResponse = null;
    var jsonData = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';
    let url = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"; //or production  

    requestDependency.post({

        headers: {    
            'content-type': 'XXXXXXXXXXXXXXXXXXXX'  ,
            'Accept': 'XXXXXXXXXXXXXXXXXXXX',
            'XXXXXXXXXX-Access-Token': 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
        },

        url: url,  
        body: jsonData 

    }, function(error, response, body) { 

        if (error) {  
            console.log('errrrrrrrror1')
        } else {
            jsonResponse = body;
            console.log(jsonResponse); <-----Shows correct data returned
            console.log('Done.');
            answer = jsonResponse;
            console.log('TEST: ' + answer)
        }
    });

    console.log("Performing search");
    response.send(cardName+" "+jsonResponse); <---jsonResponse not populated
});

Answer 1

根据documentation，当响应发送到客户端时，HTTP函数终止。这意味着您对response.send（）的调用有效地终止了该函数。

问题是对post()的调用是异步的，并且在HTTP请求在后台继续的同时立即返回。发布后，函数将继续执行。这意味着您发送的响应几乎肯定会在HTTP请求完成之前得到执行。

如果要等待HTTP请求完成，请将响应放在客户端内部中，该回调处理HTTP请求的响应。

function(error, response, body) { 
    if (error) {  
        console.log('errrrrrrrror1')
        // send an error response here
    } else {
        jsonResponse = body;
        console.log(jsonResponse); <-----Shows correct data returned
        console.log('Done.');
        answer = jsonResponse;
        console.log('TEST: ' + answer)
        // send an success response here
    }
});

也请观看此视频系列，以更好地了解Cloud Functions的工作原理：https://www.youtube.com/watch?v=7IkUgCLr5oA&index=2&list=PLl-K7zZEsYLkPZHe41m4jfAxUi0JjLgSM

Firebase http函数在http请求库返回数据之前完成

1 个答案: