我想停止我的脚本,等到最后再返回数组。如果没有操纵up节点js中的return元素,则不应继续前进。它不等待清除间隔并向前移动,因此我无法确定如何等待此处的数组结果。
我得到的结果不确定。我想要一个数组。
const puppeteer = require("puppeteer");
var page;
var browser;
async function getuser_data(callback) {
browser = await puppeteer.launch({
headless: false,
args: ["--no-sandbox", "--disable-setuid-sandbox"]
});
page = await browser.newPage();
await page.setViewport({
width: 1068,
height: 611
});
await page.goto(
"https://www.instagram.com/accounts/login/?source=auth_switcher"
);
await page.waitForSelector('input[name="username"]');
await page.type('input[name="username"]', "yourusername");
await page.type('input[name="password"]', "yourpassword");
await page.click("._0mzm-.sqdOP.L3NKy");
await page.waitFor(3000);
var y = "https://www.instagram.com/xyz/";
await page.goto(y);
await page.waitFor(2000);
var c = await page.evaluate(async () => {
await document
.querySelector(
"#react-root > section > main > div > header > section > ul > li:nth-child(2) > a"
)
.click();
var i = 0;
var timer = await setInterval(async () => {
i = i + 1;
console.log(i);
await document.querySelector(".isgrP").scrollBy(0, window.innerHeight);
var ele = await document.querySelectorAll(".FPmhX.notranslate._0imsa ")
.length;
console.log("Now length is :" + ele);
console.log("Timer :" + i);
if (ele > 10 && i > 20) {
console.log("Break");
clearInterval(timer);
console.log("after break");
var array = [];
for (var count = 1; count < ele; count++) {
try {
var onlyuname = await document.querySelector(
`body > div.RnEpo.Yx5HN > div > div.isgrP > ul > div > li:nth-child(${count}) > div > div.t2ksc > div.enpQJ > div.d7ByH > a`
).innerText;
console.log(onlyuname);
var obj = {
username: onlyuname
};
console.log(obj);
await array.push(obj);
} catch (error) {
console.log("Not found");
}
}
console.log(JSON.stringify(array));
return array; //Should Wait Till return , it should not move forward
}
}, 800);
});
console.log(c) //IT should return me array, Instead of undefined
callback(c)
}
getuser_data(users => {
console.log(users)
let treeusernamefile = JSON.stringify(users);
fs.writeFileSync('tablebay.json', treeusernamefile);
})
答案 0 :(得分:2)
问题是setInterval()
不能按预期工作。具体来说,它不会返回您可能Promise
的{{1}}。它会同步创建间隔,然后返回传递给await
的整个函数。
您需要做的是自己创建一个page.evaluate()
,并在准备好Promise
之后告诉resolve
。
array
请注意,上面的示例不处理错误。如果您的//...
return new Promise((resolve, reject) => {
var timer = setInterval(async () => {
i = i + 1;
console.log(i);
await document.querySelector(".isgrP").scrollBy(0, window.innerHeight);
var ele = await document.querySelectorAll(".FPmhX.notranslate._0imsa ")
.length;
console.log("Now length is :" + ele);
console.log("Timer :" + i);
if (ele > 10 && i > 20) {
console.log("Break");
clearInterval(timer);
console.log("after break");
var array = [];
for (var count = 1; count < ele; count++) {
try {
var onlyuname = await document.querySelector(
`body > div.RnEpo.Yx5HN > div > div.isgrP > ul > div > li:nth-child(${count}) > div > div.t2ksc > div.enpQJ > div.d7ByH > a`
).innerText;
console.log(onlyuname);
var obj = {
username: onlyuname
};
console.log(obj);
await array.push(obj);
} catch (error) {
console.log("Not found");
}
}
console.log(JSON.stringify(array));
resolve(array); // <-----------------
}
}, 800);
})
//...
抛出任何函数,则需要捕获这些错误,并使用setInterval
将它们传递给外部作用域。
希望这会有所帮助。
答案 1 :(得分:0)
setTimeout
,promise和递归函数可能会有所帮助。
// a normal delay function, you can call this with await
const delay = d => new Promise(r => setTimeout(r, d))
const data = [];
async function timer(i = 0) {
// Optionally set to wait 1000 ms and then continue
await delay(1000)
// click element, grab data etc.
console.log(`Clicking element ${i}`);
data.push(i);
// check for condition fulfillment, you can basically put any limit here
if (i >= 10) return data;
// return another promise recursively here
return timer(i + 1)
}
timer().then(console.log)
运行代码片段以查看实际效果。它应该递归地显示控制台,直到达到某个极限为止。
它的工作方式是,如果条件尚未满足,它将返回另一个promise。您可以无限调用它并清除超时(也就是返回一个数据而不是另一个计时器承诺)。