Html Scraping And Css Queries
what are the advantages and disadvantages of the following libraries? PHP Simple HTML DOM Parser QP phpQuery From the above i've used QP and it failed to parse invalid HTML, and
Solution 1:
I used to use simple html dom exclusively until some bright SO'ers showed me the light hallelujah.
Just use the built in DOM functions. They are written in C and part of the PHP core. They are faster more efficient than any 3rd party solution. With firebug, getting an XPath query is muey simple. This simple change has made my php based scrapers run faster, while saving my precious time.
My scrapers used to take ~ 60 megabytes to scrape 10 sites asyncronously with curl. That was even with the simple html dom memory fix you mentioned.
Now my php processes never go above 8 megabytes.
Highly recommended.
EDIT
Okay I did some benchmarks. Built in dom is at least an order of magnitude faster.
Built in php DOM: 0.007061
Simple html DOM: 0.117781<?include("../lib/simple_html_dom.php");
$html = file_get_contents("http://stackoverflow.com/search?q=favorite+programmer+cartoon");
$data['dom'] = $data['simple_dom'] = array();
$timer_start = microtime(true);
$dom = new DOMDocument();
@$dom->loadHTML($html);
$x = new DOMXPath($dom);
foreach($x->query("//a") as$node)
{
$data['dom'][] = $node->getAttribute("href");
}
foreach($x->query("//img") as$node)
{
$data['dom'][] = $node->getAttribute("src");
}
foreach($x->query("//input") as$node)
{
$data['dom'][] = $node->getAttribute("name");
}
$dom_time = microtime(true) - $timer_start;
echo"built in php DOM : $dom_time\n";
$timer_start = microtime(true);
$simple_dom = new simple_html_dom();
$simple_dom->load($html);
foreach( $simple_dom->find("a") as$node)
{
$data['simple_dom'][] = $node->href;
}
foreach( $simple_dom->find("img") as$node)
{
$data['simple_dom'][] = $node->src;
}
foreach( $simple_dom->find("input") as$node)
{
$data['simple_dom'][] = $node->name;
}
$simple_dom_time = microtime(true) - $timer_start;
echo"simple html DOM : $simple_dom_time\n";
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