如何在Google Cloud Puppeteer函数内部传递两个参数？解析以请求JSON

Andrew 发表于 Dev

安德鲁

我正在构建一个带有两个参数的应用程序；请求网址和CSS查询选择器。我很难让请求看起来像这样：“ http：// localhost：5000 / scrapeme / us-central1 / scraperSelector？requestURL = https：//www.google.com&selector=#hplogo ”。该请求不接受选择器变量，并且返回未定义。

我不太确定自己在做什么错，我尝试了不同的方法，例如request.body或创建对象并将其传递给代码。我已经阅读了Google文档，却找不到在云函数中传递多个参数的好例子。

const admin = require('firebase-admin');
const functions = require('firebase-functions');
const puppeteer = require("puppeteer");
const chalk = require("chalk");

admin.initializeApp();

// for yellow console logging
const checking = chalk.bold.yellow;

// const uri = "http://localhost:5000/scrapeme/us-central1/scraperSelector";
// const appURL = "scrapeme.firebaseapp.com";


exports.scraperSelector = functions.runWith({ memory: '1GB' }).https.onRequest(async(request, response) => {
    // initialize varialbe to request params
    const requestURL = request.query.requestURL;
    console.log("Evaluating " + requestURL);

    let selector = request.query.selector;
    console.log("Evaluating " + selector);

    console.log("Evaluating " + request.originalUrl);

    // Launch a browser
    const browser = await puppeteer.launch({
        headless: true,
        args: ['--no-sandbox', '--disable-setuid-sandbox']
    });

    // Visit the page a get content
    const page = await browser.newPage();

    // Go to requested URL
    await page.goto(requestURL, { waitUntil: 'networkidle0' });
    console.log(checking("Evaluating " + requestURL));

    // find the css selector
    const content = await page.evaluate(() => {
        console.log(JSON.stringify(selector));

        let selectorCSS = document.querySelector(selector).innerText;
        console.log(selectorCSS);

        return selectorCSS;

    },);

    // Send the response
    response.json(content);

});

// Example URL of how request should look
// http://localhost:5000/scrapeme/us-central1/scraperSelector?requestURL=https://www.google.com&selector=#hplogo

我希望输出解析为JSON响应。我正在尝试从页面中抓取单个项目。{“结果”：“ $ 18.41”}

但是，我得到此输出和错误：

评估https://www.google.com

评估

评估/ scrapeme / us-central1 / scraperSelector？requestURL = https：//www.google.com&selector=

评估https://www.google.com

！函数：错误：评估失败：ReferenceError：在puppeteer_evaluation_script中未定义选择器：2：36

叶文

您必须将selector变量传递给evaluate函数。

    //...
    let selector = request.query.selector;
    //...
    const content = await page.evaluate(selector => { // <-- add the `selector` variable.
    console.log(JSON.stringify(selector));

    let selectorCSS = document.querySelector(selector).innerText;
    console.log(selectorCSS);

    return selectorCSS;

    }, selector); // <-- add the `selector` variable

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