laurengarcia / url-metadata

NPM module: Request a url and scrape the metadata from its HTML using Node.js or the browser.
https://www.npmjs.com/package/url-metadata
MIT License
166 stars 43 forks source link

url-metadata

Request a url and scrape the metadata from its HTML using Node.js or the browser. Has an alternate mode that lets you pass in your own Response object as well (see Options).

Includes:

More details in the Returns section below.

To report a bug or request a feature please open an issue or pull request in GitHub. Please read the Troublehsooting section below before filing a bug.

Usage

Works with Node.js version >=18.0.0 or in the browser when bundled with Webpack or Parcel (see /example-typescript). Under the hood, this package does some post-request processing on top of the js-native fetch API. Use previous version 2.5.0 which uses the (now-deprecated) request module if you don't have access to fetch API in your target environment.

Install in your project:

$ npm install url-metadata --save

In your project file:

const urlMetadata = require('url-metadata');

try {
  const url = 'https://www.npmjs.com/package/url-metadata';
  const metadata = await urlMetadata(url);
  console.log(metadata);
} catch (err) {
  console.log(err);
}

Options & Defaults

The default options are the values below. To override the default options, pass in a second options argument.

const options = {
  // custom request headers
  requestHeaders: {
    'User-Agent': 'url-metadata/3.0 (npm module)',
    'From': 'example@example.com'
  },

  // `fetch` API cache setting for request
  cache: 'no-cache',

  // `fetch` API mode (ex: 'cors', 'no-cors', 'same-origin', etc)
  mode: 'cors',

  // charset to decode response with (ex: 'auto', 'utf-8', 'EUC-JP')
  // defaults to auto-detect in `Content-Type` header or meta tag
  // if none found, default `auto` option falls back to `utf-8`
  // override by passing in charset here (ex: 'windows-1251'):
  decode: 'auto',

  // timeout in milliseconds, default is 10 seconds
  timeout: 10000,

  // number of characters to truncate description to
  descriptionLength: 750,

  // force image urls in selected tags to use https,
  // valid for images & favicons with full paths
  ensureSecureImageRequest: true,

  // return raw response body as string
  includeResponseBody: false,

  // alternate use-case: pass in `Response` object here to be parsed
  // see example below
  parseResponseObject: null,
};

// Basic usage
try {
  const url = 'https://www.npmjs.com/package/url-metadata';
  const metadata = await urlMetadata(url, options);
  console.log(metadata);
} catch (err) {
  console.log(err);
}

// Alternate use-case: parse a Response object instead
try {
  // fetch the url in your own code
  const response = await fetch('https://www.npmjs.com/package/url-metadata');
  // ... do other stuff with it...
  // pass the `response` object to be parsed for its metadata
  const metadata = await urlMetadata(null, { parseResponseObject: response });
  console.log(metadata);
} catch (err) {
  console.log(err);
}
// ...If instead you need to parse a string of html you can create a response object and pass the html string into it. See example in test/options.test.js file.

Returns

Returns a promise resolved with an object. Note that the url field returned will be the last hop in the request chain. If you pass in a url from a url shortener you'll get back the final destination as the url.

The returned metadata object consists of key/value pairs that are all strings, with a few exceptions:

A basic template for the returned metadata object can be found in lib/metadata-fields.js. Any additional meta tags found on the page are appended as new fields to the object.

Troubleshooting

Issue: Response status code 0 or CORS errors. The fetch request failed at either the network or protocol level. Possible causes:

Issue: fetch is not defined. Error thrown in a Node.js or browser environment that doesn't have fetch method available. Try upgrading your environment (Node.js version >=18.0.0), or you can use an earlier version of this package (version 2.5.0).

Issue: Request returns 404, 403 errors or a CAPTCHA form. Your request may have been blocked by the server because it suspects you are a bot or scraper. Check this list to ensure you're not triggering a block.