I'm trying to scrape prices from multiple pages using puppeteer. What i'm having trouble with, is to write a single JSON file with all the scraped data. The problem is that if i try to write the file with the variables from inside the async function, i get an error saying that that variable hasn't been declared.
async function scrapeVMZ(url) {
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto(url);
const [vmzel1] = await page.$x('//*[@id="__layout"]/div/div[1]/section/div/div/div[2]/div[2]/div[1]/div/div/div[2]/div/div[1]/span[2]');
const vmztxt1 = await vmzel1.getProperty('textContent');
const vmzRawTxt1 = await vmztxt1.jsonValue();
const [vmzel2] = await page.$x('//*[@id="__layout"]/div/div[1]/section/div/div/div[2]/div[2]/div[1]/div/div/div[2]/div/div[1]/span[4]/b');
const vmztxt2 = await vmzel2.getProperty('textContent');
const vmzRawTxt2 = await vmztxt2.jsonValue();
console.log({vmzRawTxt1, vmzRawTxt2});
const vmz01 = JSON.stringify(vmzRawTxt1);
const vmz02 = JSON.stringify(vmzRawTxt2);
console.log(vmz01, vmz02);
browser.close();
}
scrapeVMZ('https://www.vmzviagens.com.br/ingressos/orlando/walt-disney-orlando');
async function scrapeMB(url) {
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto(url);
const [mbel1] = await page.$x('/html/body/section[3]/div/div/div[2]/div[1]/div/div[2]/a[1]/span[2]/span/div/div[2]/span');
const mbtxt1 = await mbel1.getProperty('textContent');
const mbRawTxt1 = await mbtxt1.jsonValue();
const [mbel2] = await page.$x('/html/body/section[3]/div/div/div[2]/div[1]/div/div[2]/a[1]/span[2]/span/div/div[4]/span');
const mbtxt2 = await mbel2.getProperty('textContent');
const mbRawTxt2 = await mbtxt2.jsonValue();
console.log({mbRawTxt1, mbRawTxt2});
const mb01 = JSON.stringify(mbRawTxt1);
const mb02 = JSON.stringify(mbRawTxt2);
console.log(mb01, mb02);
browser.close();
}
scrapeMB('https://www.ingressosmagicblue.com.br/produtos/?mpage=2');
How can i write a file, using the code above, to store inside my JSON file, the variables vmz01, vmz02 and mb01, mb02, like the example below?
let abc = {
"MB": {
preco: mb01,
preco2: mb02
},
"VMZ": {
preco: vmz01,
preco2: vmz02
}
};
When console.log appears in a function instead of returning results, that's a dead end. Return the results if you want to use them later. Since you're returning promises, you can await them in the caller, either serially or in parallel.
There's also a lot of repeated code in your functions, and you probably don't need 2 browsers. Here's a quick refactor that runs in parallel in a single browser (the preco keys are sort of awkward--I'd suggest an array here potentially).
const fs = require("fs").promises;
const puppeteer = require("puppeteer"); // ^14.3.0
const vmzPaths = [
'//*[@id="__layout"]/div/div[1]/section/div/div/div[2]/div[2]/div[1]/div/div/div[2]/div/div[1]/span[2]',
'//*[@id="__layout"]/div/div[1]/section/div/div/div[2]/div[2]/div[1]/div/div/div[2]/div/div[1]/span[4]/b',
];
const mbPaths = [
"/html/body/section[3]/div/div/div[2]/div[1]/div/div[2]/a[1]/span[2]/span/div/div[2]/span",
"/html/body/section[3]/div/div/div[2]/div[1]/div/div[2]/a[1]/span[2]/span/div/div[4]/span",
];
const scrape = async (browser, url, paths) => {
const page = await browser.newPage();
await page.goto(url);
return Promise.all(paths.map(async p =>
(await page.waitForXPath(p)).evaluate(e => e.textContent)
));
};
let browser;
(async () => {
browser = await puppeteer.launch({headless: true});
const text = await Promise.all([
scrape(browser, "https://www.ingressosmagicblue.com.br/produtos/?mpage=2", mbPaths),
scrape(browser, "https://www.vmzviagens.com.br/ingressos/orlando/walt-disney-orlando", vmzPaths),
]);
const names = ["MB", "VMZ"];
const collected = Object.fromEntries(text.map((e, i) => [
names[i], Object.fromEntries(e.map((e, i) =>
[`preco${i === 0 ? "" : (i + 1)}`, e]
))
]));
await fs.writeFile("out.json", JSON.stringify(collected, null, 2));
})()
.catch(err => console.error(err))
.finally(() => browser?.close())
;
As an aside, I'm not a big fan of hyper-precise, browser generated paths and selectors. These tend to be super brittle, and there's almost always a better way to choose a selector. But I haven't looked at the page in the interests of focusing on the promises issue, so I'll leave that as an exercise for the reader.