Why a fork
I wanted to use x-ray in a react-native projet but when I looked to the code I thought that a first refactoring was necessary. I took some liberties along the way and made some changes to the original api, it's why I created a new package called "x-ray-scraper".
Main differences with the original x-ray:
- instatiation of x-ray is different,
- all the callbacks were replaced with promises (except for the crawler),
- "x-ray-crawler" and "x-ray-parse" npm module are now included as a part of the project,
- mocha was replaced with jest.
It's not yet compatible with react-native but could be in the near future.
const x = ;
npm install x-ray-scraper
Flexible schema: Supports strings, arrays, arrays of objects, and nested object structures. The schema is not tied to the structure of the page you're scraping, allowing you to pull the data in the structure of your choosing.
Composable: The API is entirely composable, giving you great flexibility in how you scrape each page.
Pagination support: Paginate through websites, scraping each page. X-ray also supports a request
delayand a pagination
limit. Scraped pages can be streamed to a file, so if there's an error on one page, you won't lose what you've already scraped.
Crawler support: Start on one page and move to the next easily. The flow is predictable, following a breadth-first crawl through each of the pages.
Responsible: X-ray has support for concurrency, throttles, delays, timeouts and limits to help you scrape any page responsibly.
Pluggable drivers: Swap in different scrapers depending on your needs.
url for the following
selector, returning an object via a promise.
selector takes an enhanced jQuery-like string that is also able to select on attributes. The syntax for selecting on attributes is
selector@attribute. If you do not supply an attribute, the default is selecting the
Here are a few examples:
- Scrape a single tag
console; // Google)ORconst title = await ;console;
- Scrape a single class
- Scrape an attribute
xray(url, scope, selector)
You can also supply a
scope to each
selector. In jQuery, this would look something like this:
xray(html, scope, selector)
Instead of a url, you can also supply raw HTML and all the same semantics apply.
const html = "<body><h2>Pear</h2></body>";
driver to make requests through. Available drivers include:
- request - A simple driver built around request. Use this to set headers, cookies or http methods.
Returns Readable Stream of the data. This makes it easy to build APIs around x-ray. Here's an example with Express:
const app = ;const x = ;app
Stream the results to a
If no path is provided, then the behavior is the same as .stream().
Promise object and invoke its
then function with a callback
cb. Be sure to invoke
then() at the last step of xray method chaining.
url from a
selector and visit that page.
Also accept a function as argument.
selector function receives two arguments:
pageNumber: The next page number (first call with value 2)
$: Cheerio object if you want to select stuffs to compute the next url.
Limit the amount of pagination to
Abort pagination if
validator function returns
validator function receives two arguments:
result: The scrape result object for the current page.
nextUrl: The URL of the next page to scrape.
Delay the next request between
from is specified, delay exactly
Set the request concurrency to
n. Defaults to
Throttle the requests to
n requests per
Specify a timeout of
ms milliseconds for each request.
X-ray also has support for selecting collections of tags. While
x('ul', 'li') will only select the first list item in an unordered list,
x('ul', ['li']) will select all of them.
Additionally, X-ray supports "collections of collections" allowing you to smartly select all list items in all lists with a command like this:
X-ray becomes more powerful when you start composing instances together. Here are a few possibilities:
Crawling to another site
const x = ;;
Scoping a selection
const x = ;
Filters can be specified with setFilters method. To apply filters to a value, append them to the selector using
const x = ;x;
Create multiple instances
Sometimes, you may need to instantiate multiple instances of xray.
const Xray = ;const xOne = ;// Optionnal parameter: driverconst xTwo = ;;;
- selector: simple string selector
- collections: selects an object
- arrays: selects an array
- collections of collections: selects an array of objects
- array of arrays: selects an array of arrays