我正在尝试检查 og:image
源是否存在。如果我想调用 evaluate 中的异步方法函数时,我收到 Error:Evaluation failed:[object Object]
错误。
Error: Evaluation failed: [object Object]
at ExecutionContext._evaluateInternal (.../node_modules/puppeteer/lib/ExecutionContext.js:122:13)
at processTicksAndRejections (internal/process/task_queues.js:89:5)
at async ExecutionContext.evaluate (.../node_modules/puppeteer/lib/ExecutionContext.js:48:12)
-- ASYNC --
at ExecutionContext.<anonymous> (.../node_modules/puppeteer/lib/helper.js:111:15)
at DOMWorld.evaluate (.../node_modules/puppeteer/lib/DOMWorld.js:112:20)
at processTicksAndRejections (internal/process/task_queues.js:89:5)
-- ASYNC --
at Frame.<anonymous> (.../node_modules/puppeteer/lib/helper.js:111:15)
at Page.evaluate (.../node_modules/puppeteer/lib/Page.js:827:43)
at Page.<anonymous> (.../node_modules/puppeteer/lib/helper.js:112:23)
at run (/Users/andrejgajdos/devel/link-preview/app.js:195:28)
at processTicksAndRejections (internal/process/task_queues.js:89:5)
app.sj
const puppeteer = require("puppeteer");
const util = require('util');
const urlExists = util.promisify(require('url-exists'));
const run = async () => {
try {
const browser = await puppeteer.launch({ headless: true });
const page = await browser.newPage();
await page.goto('https://www.onepeloton.com/', { waitUntil: 'domcontentloaded' });
const img = await page.evaluate(async () => {
const ogImg = document.querySelector('meta[property="og:image"]');
if (ogImg != null && ogImg.content.length > 0) {
const isExists = await urlExists(ogImg.content);
return isExists;
}
});
console.log(img);
await browser.close()
} catch (e) {
console.log(e);
}
}
run();
最佳答案
evaluate
中的所有代码都在 chromium 端执行。
由于 urlExists
是在 Node 端导入的,因此您无法从浏览器访问该函数。
除非您使用 page.exposeFunction 公开它。一旦您公开该函数,Chromium 将能够调用 urlExists
。
const browser = await puppeteer.launch({ headless: true });
const page = await browser.newPage();
await page.goto('https://www.onepeloton.com/', { waitUntil: 'domcontentloaded' });
await page.exposeFunction('urlExists', urlExists);
const img = await page.evaluate(async () => {
const ogImg = document.querySelector('meta[property="og:image"]');
if (ogImg != null && ogImg.content.length > 0) {
const isExists = await urlExists(ogImg.content);
return isExists;
}
});
console.log(img);
await browser.close()
关于javascript - Puppeteer - 评估方法中的异步函数引发错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57908630/