cheerio-advanced-selectors

cheerio-advanced-selectors

Add support for the following selectors to cheerio:

• :first
• :last
• :eq(index)

More selectors can easily be added: Just open an issue and I'll look into it :)

This module is inspired by cheerio-eq with the added support for many different selectors.

Supports cheerio version 0.18.0 and above.

Installation

npm install cheerio-advanced-selectors

Usage

Use the .wrap() function to make cheerio-advanced-selectors take care of everything for you:

var cheerio = require('cheerio')
var cheerioAdv = require('cheerio-advanced-selectors')

cheerio = cheerioAdv.wrap(cheerio)

var $ = cheerio.load('<div>foo</div><div>bar</div>')

$('div:first').text() // => 'foo'

Advanced usage

Alternatively use the .find() function to only use cheerio-advanced-selectors for a specific selector:

var cheerio = require('cheerio')
var cheerioAdv = require('cheerio-advanced-selectors')

var $ = cheerio.load('<div><span>foo</span></div><div><span>bar</span></div>')

cheerioAdv.find($, 'div:eq(1)').text() // => 'bar'

If you need to run the same selector on a lot of different HTML documents, you can speed things up by pre-compiling the selector using the .compile() function:

var cheerio = require('cheerio')
var cheerioAdv = require('cheerio-advanced-selectors')

var myH1 = cheerioAdv.compile('div:first span:eq(1) h1')

var html1 = cheerio.load('<div><span><h1>foo1</h1></span><span><h1>bar1</h1></span></div>')
var html2 = cheerio.load('<div><span><h1>foo2</h1></span><span><h1>bar2</h1></span></div>')

myH1(html1).text() // => 'bar1'
myH1(html2).text() // => 'bar2'

What's the problem?

Cheerio sacrifices advanced CSS selector support for speed. This means for instance that the :eq() selector isn't supported. The work-around is normally to use the .eq() function instead:

// this will not work:
$('div:eq(1)');

// use this instead:
$('div').eq(1);

This is a good alternative if you write the CSS selectors from scrach, but what if you are working with selectors that already contain :eq()? Don't fear, cheerio-advanced-selectors is here :)

Solution

The solution to the problem is to automatically parse the selector string at run-time. So if you give cheerio-advanced-selectors a selector like div:eq(1) it will return the following cheerio cursor: $('div').eq(1).

It also works for complex selectors, so that div:eq(1) h2:first span will be converted and interpreted as $('div').eq(1).find('h2').first().find('span').

Supported advanced selectors

This module currently only support a minimal subset of the possible advanced selectors:

• :first
• :last
• :eq(index)

But don't fear :) It's easy to add support for other selectors. Just open an issue or make a pull request.

API

.wrap(cheerio)

Wraps the main cheerio module to overload the standard load function so it knows how to handle the advanced selectors.

Returns the cheerio module.

.find(cheerio, selector [, context [, root]])

Run the selector on the given cheerio object optionally within the given context and optionally on the given root.

The cheerio object is usually called $.

.compile(selector)

Compiles the selector and returns a function which take 3 arguments: fn(cheerio [, context [, root]]):

• cheerio - a reference to the cheerio object (usually called $)
• context - the context in which to run the selector (optional)
• root - the HTML root on which to run the selector (optional)

License

MIT