Facebook-Like Link Preview (no longer maintained)

Disclaimer: I will no longer maintain this project because it's an old code and hard to maintain, but I'm exporting this logic to Angularjs and Bootstrap. I believe this a great solution for an easy comprehension of the code and will allow the project to evolve even further. You can found this new project here >> https://github.com/LeonardoCardoso/Link-Preview

Developed by @LeonardoCardoso.

How this works

The algorithm keeps tracking what you are typing in the status field and through regular expressions identifies a url. Thereafter, the text is in the field is passed to PHP that does all the work to analyze all the source code of the url found. If you enter more than one url, it will consider that the first one is the more relevant and it will create a preview. Once the source code of the url is obtained, regular expressions begin to seek out and capture relevant information on it. This information is basically the title page, the images contained therein, and a brief description of the content covered in the page.

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HTTP Server

• Apache (must support mod_php)

How to add it to your project

1 • Scripts

	<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js'></script>

	<script src='js/linkPreview.js' ></script>

 	<!-- 
		If you are saving and fetching results from database using FLP,
		you can customize the layout on this script
	-->
	<script src='js/linkPreviewRetrieve.js' ></script>

2 • Stylesheets

	<!-- 
		This stylesheet is provides the layout of Facebook's former textarea. 
		You can totally customize this!
	-->
	<link rel="stylesheet" type="text/css" href="css/linkPreview.css" />

3 • Configuration

Just create your own textarea (or multiple textareas) and bind it to jQuery like this:

	<script>
		$(document).ready(function() {
			$('#lp1').linkPreview();

			// changing placeholder
			$('#lp2').linkPreview({placeholder: "Second Field"});
			
			// bind to a tag the results brought from database
			$('#retrieveFromDatabase').linkPreviewRetrieve();
		});
	</script>
	

4 • Database

To custom your database configurations, you just need to change the following values in php/classes/Database.php

	$host = "localhost";
    $user = "";
    $password = "";
    $database = "linkpreview";

Make sure your columns are the same as those ones in linkpreview.sql.

Result Format

	{  
	   "title":"title",
	   "url":"original url",
	   "pageUrl":"page url",
	   "canonicalUrl":"cannonical url",
	   "description":"description",
	   "images": "img1|img2|...",
	   "video":"yes|no",
	   "videoIframe":"video iframe if it is video"
	}

Parameters

option	default value	possible values	function
imageQuantity	-1	any integer	set the max amount of images to be brought (-1 for illimited)
placeholder	What's in your mind	any string	set the placeholder of textarea

Important

Make sure the library php5-curl is installed and enabled on the server, either locally or remotely.

• Linux

$ sudo apt-get install php5-curl
$ sudo service apache2 restart

• Mac (via macports)

$ sudo port install php5-curl 
$ sudo apachectl restart

Contact

Contact me either by Twitter @leocardz or emailing me to contact@leocardz.com.

License

Copyright (c) 2014 Leonardo Cardoso (http://leocardz.com)
Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.