FB like Page details extractor from URL with PHP DOMDocument

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I like one feature about facebook while updating status is that whenever I paste a URL, it grabs the primary details about the page and shows immediately. Which increases the chances that person viewing the post will more likely will click on it since he/she gets the summary right away.

I thought of mimicking the similar functionality using PHP. Well so why not lets try it.

Level: Beginner

You should be aware of the DOMDocument Class of PHP. If not please have a look at DOMDocument on php.net. Manual is more than enough to learn DOMDocument.

We are going to use very basic functions of the DOMDocument viz:
1. loadHTMLFile
2. getElementsByTagName

We are going to create this in 3 very simple steps:

  1. Get a URL for which we want to fetch the details
  2. With the use of DOMDocument fetch the details
  3. Print the essential details

We are going to create a class for the same, so that if required we can use it anywhere we want.

TO START WITH:
We will create a very simple HTML form where the user will enter the URL:

<!DOCTYPE HTML>
<html>
	<head>
		<title>Page Extractor</title>
	</head>
<body>
	<form method="get" action="">
		<input type="text" name="url" />
	</form>
	<div class="pageinfo">
		<!-- -->
	</div>
</body>

Also we will use the following class skeleton to write the feature

// its the very basic singleton class
class Extractor
{
	private static $instance;
	public $url;

	public function __construct()
	{
		if(!self::$instance)
		{
			self::$instance = $this;
		}
		return self::$instance;
	}

	private function getUrl()
	{
		// it will check for the url
	}

	private function extractDetails()
	{
		// it will actually extract the details using DOMDocument
	}

	private function printDetails()
	{
		// it will just organise the fetched/extracted details
	}

	public function getPageDetails()
	{
		// this is the only exposed function to public
	}

}

Lets move on to steps now:

Step 1: Get a URL for which we want to fetch the details

We will just check whether the user has entered the URL before submitting the form in the following way.

private function getUrl()
{
	// you should also add the validation of URL over here to check for valid url
	if(isset($_GET['url']) && $_GET['url'] != '')
	{
		return $_GET['url'];
	}
	else
	{
		return false;
	}
}

Step 2: With the use of DOMDocument fetch the details

We will use the loadHTMLFile to load the URL and then perform operations to get the details out of it.

We are basically looking for following things:

  1. title of the page
  2. images on the page
  3. meta information about the page
private function extractPageDetails()
{
	$arrDetails =  null;
	$doc = new DOMDocument();
	// added @ to suppress the errors
	@$doc->loadHTMLFile($this->url);

	foreach($doc->getElementsByTagName('title') as $title)
	{
		$arrDetails['title'] = $title->nodeValue;
	}

	foreach($doc->getElementsByTagName('meta') as $meta)
	{
		// since there are lot of meta tags available with name:content
		// we will create a array of meta tags and lets see ahead what all we can use
		$arrDetails['meta'][$meta->getAttribute('name')] = $meta->getAttribute('content');
	}

	foreach($doc->getElementsByTagName('img') as $img)
	{
		// we will fetch all the images on the page and put it in array
		$arrDetails['images'][] = $img->getAttribute('src');
	}

	return $arrDetails;
}

Step 3: Print the essential details.

Well this is the just the function which will print the details fetched in Step 2

private function printDetails($pageDetails)
{
	$strHTML = '';

	$strHTML .= '<h2>'.$pageDetails['title'].'</h2>';
	$strHTML .= '<div>';
		if(isset($pageDetails['images']))
		{
			$strHTML .= '<img src="'.$pageDetails['images'][0].'" />';
		}
		if(isset($pageDetails['meta']['description']))
		{
			$strHTML .= '<p>';
				$strHTML .= $pageDetails['meta']['description'];
			$strHTML .= '</p>';
		}

	$strHTML .= '</div>';

	return $strHTML;
}

Here how the complete program will look. Have added very basic CSS to it

<?php
	// FB like Page details extractor from URL with PHP DOMDocument
	class Extractor
	{
		private static $instance;
		public $url;

		public function __construct()
		{
			if(!self::$instance)
			{
				$this->url = $this->getUrl();
				self::$instance = $this;
			}
			return self::$instance;
		}

		private function getUrl()
		{
			if(isset($_GET['url']) && $_GET['url'] != '')
			{
				return $_GET['url'];
			}
			else
			{
				return false;
			}
		}

		private function extractPageDetails()
		{
			$arrDetails =  null;
			$doc = new DOMDocument();
			@$doc->loadHTMLFile($this->url);

			foreach($doc->getElementsByTagName('title') as $title)
			{
				$arrDetails['title'] = $title->nodeValue;
			}

			foreach($doc->getElementsByTagName('meta') as $meta)
			{

				$arrDetails['meta'][$meta->getAttribute('name')] = $meta->getAttribute('content');
			}

			foreach($doc->getElementsByTagName('img') as $img)
			{
				$arrDetails['images'][] = $img->getAttribute('src');
			}

			return $arrDetails;
		}

		private function printDetails($pageDetails)
		{
			$strHTML = '';

			$strHTML .= '<h2>'.$pageDetails['title'].'</h2>';
			$strHTML .= '<div>';
				if(isset($pageDetails['images']))
				{
					$strHTML .= '<img src="'.$pageDetails['images'][0].'" />';
				}
				if(isset($pageDetails['meta']['description']))
				{
					$strHTML .= '<p>';
						$strHTML .= $pageDetails['meta']['description'];
					$strHTML .= '</p>';
				}

			$strHTML .= '</div>';

			return $strHTML;
		}

		public function getPageDetails()
		{
			if($this->url)
			{
				$pageDetails = $this->extractPageDetails();
				return $this->printDetails($pageDetails);
			}
			else
			{
				return '';
			}

		}
	}
	$ext = new Extractor;
?>
<!DOCTYPE HTML>
<html>
	<head>
		<title>Page Extractor</title>
		<style type="text/css">
			h2,p,img,div{ padding:0;margin:0 }
			.pageinfo{ background:#eee; font-family: Tahoma; padding:10px; overflow:hidden; }
			.pageinfo h2{ }
			.pageinfo img{ float:left; height:100px; width:100px; }
			.pageinfo p{ float:left }
		</style>
	</head>
<body>
	<form method="get" action="">
		<input type="text" name="url" />
	</form>
	<div class="pageinfo">
		<?php
			if($ext->url)
			{
				echo $ext->getPageDetails();
			}
		?>
	</div>
</body>

Well thats it, this is for the beginners level. Its not even a tutorial but just the introduction to DOMDocument class and how it can be used.

Demo Page

Directory Listing with PHP file & dir functions

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I always had a habit of managing everything in different folders, be it the documents, photographs, programs or projects. So when I started web development, everyday I use to endup creating something new in the new folder.
But then more the folders, more difficult to manage and remember whats in it although I use to make sure to give it a intutive name.

Then one day I decided to make my www folder more manageable or basically more identifiable. So I wrote a small program to display all the folders in an HTML file neatly.
And dropped a README file into the folder with very short description which would displayed along with the folder name on the HTML page.

Level: Beginner

Requirements: What we require here are very basic directory & file operations in PHP. We will learns them while on the way. Classes in PHP.

So lets get started!!

Step 1:

We are going to write few independent functions.

A. Function getFolders():

We are going to open the directory with opendir() function.
The we are going to read each and every file and folder from the opened directory with readdir() and if its directory we are going to make a list of it.
And in the end we are going to close the directory using the closedir() function. 

<?php
function getFolders($dir) {
    $arrFolder = null;
    if ($handle = opendir($dir)) {
        while (false !== ($file = readdir($handle))) {
            if ($file != "." && $file != ".." && is_dir($file) && strpos($file, '.') === false) {
                $arrFolder[] = $file;
            }
        }
        closedir($handle);
    }
    return $arrFolder;
}
echo '<pre>';
// we are providing '.' since it means the current directory.
print_r(getFolders('.'));
?>

This is how it will work. Click Here.

B. Function getReadMe():

This function will take the directory path as a parameter and then its going to check if README file exists under that folder by using the file_exists() function.
If the file exists then we are going to read the content of the file with file_get_content() function.
if the README file does not exists then we going to put a default message. 

<?php
function getReadMe($dir) {
    $filepath = $dir . '/README';
    if (file_exists($filepath)) {
        return substr(file_get_contents($filepath), 0, 100);
    } else {
        return 'No README file found for this folder';
    }
}

echo getReadMe('testfolder1');
echo '<hr />';
echo getReadMe('testfolder2');
?>

This is how it will work. Click Here.

Step 2:

Now we are going to use the above written function to complete out program. We are going to write a simple class to achive this.
Final script would be like this – with little loops of arrays and HTML and CSS. 

<?php

error_reporting(E_ALL);

class DirList {

    public $dirtoread = null;
    function __construct($dir) {
        $this->dirtoread = $dir;
    }

    function getFolders($dir) {
        $arrFolder = null;
        if ($handle = opendir($dir)) {
            while (false !== ($file = readdir($handle))) {
                if ($file != "." && $file != ".." && is_dir($file) && strpos($file, '.') === false) {
                    $arrFolder[] = $file;
                }
            }
            closedir($handle);
        }
        return $arrFolder;
    }

    function getReadMe($dir) {
        $filepath = $dir . '/README';
        if (file_exists($filepath)) {
            return substr(file_get_contents($filepath), 0, 100);
        } else {
            return 'No README file found for this folder';
        }
    }

    function printList() {
        $strHTML = '<ul>';

        $arrFolderList = $this->getFolders($this->dirtoread);

        if (!empty($arrFolderList) && is_array($arrFolderList)) {
            if (count($arrFolderList) > 0) {
                foreach ($arrFolderList as $directory) {
                    $strHTML .= '<li><h2><a href="' . $directory . '">' . $directory . '</a></h2><p>' . $this->getReadMe($directory) . '</p></li>';
                }
            } else {
                $strHTML .= '<li>no folder found</li>';
            }
        }
        $strHTML .= '</ul>';
        return $strHTML;
    }

}

$dir = new DirList('.');
echo '<!DOCTYPE html>
<html>
<head>
<title>List of demos</title>
<style>
body,ul,li,a,h2,p{padding:0;margin:0}
body{background:#EEE;font-family:Verdana, Ubuntu;}
ul{list-style:none;padding:15px;}
li{background:#aaa;display:block;float:left;width: 18%;margin: 10px;padding: 5px 10px;height:150px;}
h2{border-bottom:1px solid #DDD}
a{text-decoration:none;}
p{padding:15px 5px;}
</style>
</head>
<body>' . $dir->printList() . '</body>
</html>';
?>

This is the final step. Click Here.

Conclusion:

I hope you liked very simple but kind of effective PHP snippet. Will like if you got any suggestions or comments to make.

Learning Regular Expressions – Resource

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Regular Expression is one the the powerful term in programming world. It has become the part of the daily programming world. Although it might be simple form validation in javascript or pattern matching while crawling the webpage and yes you can do it with Regular Expression.

Javascript, PHP, MySQL, Python…. list does not end…. regular expression is an in built part of it. And if not then surely it has some library to support it in some way or the other.

Those who know it, can create magic on the go, and those who don’t know it are afraid like hell. My suggestion go visit the hell and you will never regret a thing about it.

Following are the the few resource from the site www.webtechtuts.com

All Regular Expression articles on Webtechtuts.com
Regex Category on Webtechtuts.com

Regular Expression:

  1. Learn writing regular expression in 60 minutes
  2. Regex – Literal Characters And Special Characters
  3. Regex – How a Regex Engine Works Internally?
  4. Regex – Character Classes or Character Sets
  5. Regex – Dot Matches (Almost) Any Character
  6. Regex – Start and End of String or Line Anchors
  7. Regex – Word Boundries in Regular Expression
  8. Regex – Alternation
  9. Regex – Optional Item
  10. Regex – Repetition Using Various Quantifiers
  11. Regex – Matching Modes
  12. Regex – Free Spacing
  13. Regex – Adding Comments

All the best. Rule Regular Expression.