扩展新函数给window

page.exposeFunction(name, puppeteerFunction)

name <string> Name of the function on the window object
puppeteerFunction <function> Callback function which will be called in Puppeteer's context.
returns: <Promise>

The method adds a function called name on the page's window object. When called, the function executes puppeteerFunction in node.js and returns a Promise which resolves to the return value of puppeteerFunction.

If the puppeteerFunction returns a Promise, it will be awaited.

NOTE Functions installed via page.exposeFunction survive navigations.

An example of adding an md5 function into the page:

const puppeteer = require('puppeteer');

const crypto = require('crypto');

puppeteer.launch().then(async browser => {

  const page = await browser.newPage();

  page.on('console', msg => console.log(msg.text()));

  await page.exposeFunction('md5', text =>

    crypto.createHash('md5').update(text).digest('hex')

  );

  await page.evaluate(async () => {

    // use window.md5 to compute hashes

    const myString = 'PUPPETEER';

    const myHash = await window.md5(myString);

    console.log(`md5 of ${myString} is ${myHash}`);

  });

  await browser.close();

});

An example of adding a window.readfile function into the page:

const puppeteer = require('puppeteer');

const fs = require('fs');

puppeteer.launch().then(async browser => {

  const page = await browser.newPage();

  page.on('console', msg => console.log(msg.text()));

  await page.exposeFunction('readfile', async filePath => {

    return new Promise((resolve, reject) => {

      fs.readFile(filePath, 'utf8', (err, text) => {

        if (err)

          reject(err);

        else

          resolve(text);

      });

    });

  });

  await page.evaluate(async () => {

    // use window.readfile to read contents of a file

    const content = await window.readfile('/etc/hosts');

    console.log(content);

  });

  await browser.close();

});

巴特西

扩展新函数给window

page.exposeFunction(name, puppeteerFunction)

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