Semalt: 3 Steps To PHP Web Page Scraping

Web scraping, also called web data extraction or web harvesting, is the process of extracting data from a website or blog. This information is then used to set meta tags, meta descriptions, keywords and links to a site, improving its overall performance in the search engine results.

Two main techniques are used to scrape data:

• Document parsing – It involves an XML or HTML document that is converted to the DOM (Document Object Model) files. PHP provides us with great DOM extension.
• Regular expressions – It is a way of scraping data from the web documents in the form of regular expressions.

The issue with the scraping data of third party website is related to its copyright because you don't have permission to use this data. But with PHP, you can easily scrape data without problems connected with copyrights or low quality. As a PHP programmer, you may need data from different websites for coding purposes. Here we have explained how to get data from other sites efficiently, but before that, you should bear in mind that at the end you'll obtain either index.php or scrape.js files.

Steps1: Create Form to enter the Website URL:

First of all, you should create form in index.php by clicking on the Submit button and enter the website URL for scraping data.

<form method="post" name="scrape_form" id="scrap_form" acti>

Enter Website URL To Scrape Data

<input type="input" name="website_url" id="website_url">

<input type="submit" name="submit" value="Submit" >

</form>

Steps2: Create PHP Function to Get Website Data:

The second step is to create PHP function scrapes in the scrape.php file as it will help get data and use the URL library. It will also allow you to connect and communicate with different servers and protocols without any issue.

function scrapeSiteData($website_url){

if (!function_exists('curl_init')) {

die('cURL is not installed. Please install and try again.');

}

$curl = curl_init();

curl_setopt($curl, CURLOPT_URL, $website_url);

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

$output = curl_exec($curl);

curl_close($curl);

return $output;

}

Here, we can see whether the PHP cURL has been installed properly or not. Three main cURLs have to be used in the functions area and curl_init() will help initialize the sessions, curl_exec() will execute it and curl_close() will help close the connection. The variables such as CURLOPT_URL are used to set the website URLs we need to scrape. The second CURLOPT_RETURNTRANSFER will help store the scraped pages in the variable form rather than its default form, which will ultimately display the entire web page.

Steps3: Scrape Specific Data from the Website:

It's time to handle the functionalities of your PHP file and scrape the specific section of your web page. If you don't want all the data from a specific URL, you should edit use the CURLOPT_RETURNTRANSFER variables and highlight the sections you want to scrape.

if(isset($_POST['submit'])){

$html = scrapeWebsiteData($_POST['website_url']);

$start_point = strpos($html, 'Latest Posts');

$end_point = strpos($html, '', $start_point);

$length = $end_point-$start_point;

$html = substr($html, $start_point, $length);

echo $html;

}

We suggest you to develop the basic knowledge of PHP and the Regular Expressions before you use any of these codes or scrape a particular blog or website for personal purposes.