XPathSelector
Description
XPathSelector is a libary created for HTML webscraping. It was inspired by Python's Scrapy.
It uses PHP DOM extension, so make sure you have it installed. PHP 5.4 is minimum., (*1)
Installation
Recommended way to install XPathSelector is through Composer. Run following command:, (*2)
composer require stil/xpath-selector
Introduction
The starting point of all searches is XPathSelector\Selector class. It allows you to load HTML or XML, so you can process it then. There are several methods to do it:, (*3)
use XPathSelector\Selector;
$xs = Selector::load($pathToXml);
$xs = Selector::loadHTMLFile($pathToHtml);
$xs = Selector::loadXML($xmlString);
$xs = Selector::loadHTML($htmlString);
Next thing you want to do, is to decide whether you're searching for single DOM element or multiple elements.
For single search use find($query) method., (*4)
use XPathSelector\Exception\NodeNotFoundException;
try {
$element = $xs->find('//head'); // returns first <head> element found
echo $element->innerHTML(); // print innerHTML of <head> tag
} catch (NodeNotFoundException $e) {
echo $e->getMessage(); // nothing have been found
}
And if you need multiple results, use findAll($query) instead. This method returns instance of XPathSelector\NodeListInterface. Check it out in the API., (*5)
use XPathSelector\Selector;
$urls = $xs->findAll('//a/@href');
foreach ($urls as $url) {
echo $url;
}
Do you need to check whether XPath path exists? Use findOneOrNull($query) method. It returns Node object or null, when no results were found. It works just like find($query), except it returns null instead of throwing exception., (*6)
use XPathSelector\Selector;
$doesExist = $xs->findOneOrNull('//a/@href') !== null;
sample.xml
<?xml version="1.0" encoding="ISO-8859-1" ?>
<bookstore>
<book category="COOKING">
<title lang="en">Everyday Italian</title>
<author>Giada De Laurentiis</author>
<year>2005</year>
<price>30.00</price>
</book>
<book category="CHILDREN">
<title lang="en">Harry Potter</title>
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price>
</book>
<book category="WEB">
<title lang="en">XQuery Kick Start</title>
<author>James McGovern</author>
<author>Per Bothner</author>
<author>Kurt Cagle</author>
<author>James Linn</author>
<author>Vaidyanathan Nagarajan</author>
<year>2003</year>
<price>49.99</price>
</book>
<book category="WEB">
<title lang="en">Learning XML</title>
<author>Erik T. Ray</author>
<year>2003</year>
<price>39.95</price>
</book>
</bookstore>
Search for single result
<?php
use XPathSelector\Selector;
$xs = Selector::load('sample.xml');
echo $xs->find('/bookstore/book[1]/title');
Result:, (*7)
Everyday Italian
Search for multiple results
<?php
use XPathSelector\Selector;
$xs = Selector::load('sample.xml');
foreach ($xs->findAll('/bookstore/book') as $book) {
printf(
"[Title: %s][Price: %s]\n",
$book->find('title')->extract(),
$book->find('price')->extract()
);
}
Result:, (*8)
[Title: Everyday Italian][Price: 30.00]
[Title: Harry Potter][Price: 29.99]
[Title: XQuery Kick Start][Price: 49.99]
[Title: Learning XML][Price: 39.95]
Map result set to array
<?php
use XPathSelector\Selector;
$xs = Selector::load('sample.xml');
$array = $xs->findAll('/bookstore/book')->map(function ($node, $index) {
return [
'index' => $index,
'title' => $node->find('title')->extract(),
'price' => (float)$node->find('price')->extract()
];
});
var_dump($array);
Result:, (*9)
array(4) {
[0] =>
array(3) {
'index' =>
int(0)
'title' =>
string(16) "Everyday Italian"
'price' =>
double(30)
}
[1] =>
array(3) {
'index' =>
int(1)
'title' =>
string(12) "Harry Potter"
'price' =>
double(29.99)
}
[2] =>
array(3) {
'index' =>
int(2)
'title' =>
string(17) "XQuery Kick Start"
'price' =>
double(49.99)
}
[3] =>
array(3) {
'index' =>
int(3)
'title' =>
string(12) "Learning XML"
'price' =>
double(39.95)
}
}
Wallogit.com
