Posts Tagged ‘social networking’

Freedom for Our Files: Code and Slides

Monday, May 16th, 2011

A two-day workshop, with both technical hands-on and idea-driven components. Learn to scrape data and reuse public and private information by writing custom code and using the Facebook API. Additionally, we’ll converse and conceptualize ideas to reclaim our data literally and also imagine what is possible with our data once it is ours!

Here are the slides and some of the code samples from the Freedom for Our Files (FFOF) workshop I just did in Linz at Art Meets Radical Openness (LiWoLi 2011).

The first one is a basic scraping demo that uses “find-replace” parsing to change specific words (I’m including examples below the code)

<?php

/*	Basic scraping demo with "find-replace" parsing
 *	Owen Mundy Copyright 2011 GNU/GPL */

$url = "http://www.bbc.co.uk/news/";	// 0. url to start with

$contents = file_get_contents($url);	// 1. get contents of page in a string

					// 2. search and replace contents
$contents = str_replace(		// str_replace(search, replace, string)
			"News",					
			"<b style='background:yellow; color:#000; padding:2px'>LIES</b>",
			$contents);

print $contents;			// 3. print result

?>

Basic scraping demo with “foreach” parsing

<?php

/*	Basic scraping demo with "foreach" parsing
 *	Owen Mundy Copyright 2011 GNU/GPL */
 
$url = "http://www.bbc.co.uk/news/";	// 0. url to start with

$lines = file($url);			// 1. get contents of url in an array

foreach ($lines as $line_num => $line) 	// 2. loop through each line in page
{		
					// 3. if opening string is found
	if(strpos($line, '<h2 class="top-story-header ">')) 	
	{
		$get_content = true;	// 4. we can start getting content
	}
	
	if($get_content == true)
	{
		$data .= $line . "\n";	// 5. then store content until closing string appears
	}

	if(strpos($line, "</h2>")) 	// 6. if closing HTML element found
	{
		$get_content = false;	// 7. stop getting content
	}
}

print $data;				// 8. print result

?>

Basic scraping demo with “regex” parsing

<?php

/*	Basic scraping demo with "regex" parsing
 *	Owen Mundy Copyright 2011 GNU/GPL */
 
$url = "http://www.bbc.co.uk/news/";		// 0. url to start with

$contents = file_get_contents($url);		// 1. get contents of url in a string
											
						// 2. match title
preg_match('/<title>(.*)<\/title>/i', $contents, $title);

print $title[1];				// 3. print result

?>

Basic scraping demo with “foreach” and “regex” parsing

<?php

/*	Basic scraping demo with "foreach" and "regex" parsing
 *	Owen Mundy Copyright 2011 GNU/GPL */

// url to start
$url = "http://www.bbc.co.uk/news/";

// get contents of url in an array
$lines = file($url);

// look for the string
foreach ($lines as $line_num => $line) 
{	
	// find opening string
	if(strpos($line, '<h2 class="top-story-header ">')) 
	{
		$get_content = true;
	}
	
	// if opening string is found 
	// then print content until closing string appears
	if($get_content == true) 
	{
		$data .= $line . "\n";
	}

	// closing string
	if(strpos($line, "</h2>")) 
	{
		$get_content = false;
	}
}

// use regular expressions to extract only what we need...

// png, jpg, or gif inside a src="..." or src='...' 
$pattern = "/src=[\"']?([^\"']?.*(png|jpg|gif))[\"']?/i";
preg_match_all($pattern, $data, $images);

// text from link
$pattern = "/(<a.*>)(\w.*)(<.*>)/ismU";
preg_match_all($pattern, $data, $text);

// link
$pattern = "/(href=[\"'])(.*?)([\"'])/i";
preg_match_all($pattern, $data, $link);

/* 
// test if you like
print "<pre>";
print_r($images);
print_r($text);
print_r($link);
print "</pre>";
*/

?>

<html>
<head>
<style> 
body { margin:0; } 
.textblock { position:absolute; top:600px; left:0px; }
span { font:5.0em/1.0em Arial, Helvetica, sans-serif; line-height:normal; 
background:url(trans.png); color:#fff; font-weight:bold; padding:5px } 
a { text-decoration:none; color:#900 }
</style>
</head>
<body>
<img src="<?php print $images[1][0] ?>" height="100%"> </div>
<div class="textblock"><span><a href="<?php print "http://www.bbc.co.uk".$link[2][0] ?>"><?php print $text[2][0] ?></a></span><br>
</div>
</body>
</html>

And the example, which presents the same information in a new way…

Advanced scraping demo with “regex” parsing. Retrieves current weather in any city and colors the background accordingly. The math below for normalization could use some work.

<?php

/*	Advanced scraping demo with "regex" parsing. Retrieves current 
 * 	weather in any city and colors the background accordingly. 
 *	The math below for normalization could use some work.
 *	Owen Mundy Copyright 2011 GNU/GPL */

?>

<html>
<head>
<style> 
body { margin:20; font:1.0em/1.4em Arial, Helvetica, sans-serif; } 
.text { font:10.0em/1.0em Arial, Helvetica, sans-serif; color:#000; font-weight:bold; } 
.navlist { list-style:none; margin:0; position:absolute; top:20px; left:200px }
.navlist li { float:left; margin-right:10px; }
</style>
</head>

<body onLoad="document.f.q.focus();">

<form method="GET" action="<?php print $_SERVER['PHP_SELF']; ?>" name="f">

	<input type="text" name="q" value="<?php print $_GET['q'] ?>" />
	<input type="submit" />

</form>

<ul class="navlist">
	<li><a href="?q=anchorage+alaska">anchorage</a></li>
	<li><a href="?q=toronto+canada">toronto</a></li>
	<li><a href="?q=new+york+ny">nyc</a></li>
	<li><a href="?q=london+uk">london</a></li>
	<li><a href="?q=houston+texas">houston</a></li>
	<li><a href="?q=linz+austria">linz</a></li>
	<li><a href="?q=rome+italy">rome</a></li>
	<li><a href="?q=cairo+egypt">cairo</a></li>
	<li><a href="?q=new+delhi+india">new delhi</a></li>
	<li><a href="?q=mars">mars</a></li>
</ul>

<?php

// make sure the form has been sent
if (isset($_GET['q']))
{
	// get contents of url in an array
	if ($str = file_get_contents('http://www.google.com/search?q=weather+in+'
						. str_replace(" ","+",$_GET['q'])))
	{
		
		// use regular expressions to extract only what we need...
		
		// 1, 2, or 3 digits followed by any version of the degree symbol 
		$pattern = "/[0-9]{1,3}[º°]C/";
		// match the pattern with a C or with an F
		if (preg_match_all($pattern, $str, $data) > 0)
		{
			$scale = "C";
		}
		else
		{
			$pattern = "/[0-9]{1,3}[º°]F/";
			if (preg_match_all($pattern, $str, $data) > 0)
			{
				$scale = "F";
			}
		}
		
		// remove html
		$temp_str = strip_tags($data[0][0]);
		// remove everything except numbers and points
		$temp = ereg_replace("[^0-9..]", "", $temp_str);
		
		if ($temp)
		{
			
			// what is the scale?
			if ($scale == "C"){
				// convert ºC to ºF
				$tempc = $temp;
				$tempf = ($temp*1.8)+32;
			}
			else if ($scale == "F")
			{
				// convert ºF to ºC
				$tempc = ($temp-32)/1.8;
				$tempf = $temp;
			}
			// normalize the number
			$color = round($tempf/140,1)*10;
			// cool -> warm
			// scale -20 to: 120
			$color_scale = array(
					'0,  0,255',
					'0,128,255',
					'0,255,255',
					'0,255,128',
					'0,255,0',
					'128,255,0',
					'255,255,0',
					'255,128,0',
					'255,  0,0'
					);	
		
?>

<style> body { background:rgb(<?php print $color_scale[$color] ?>) }</style>
<div class="text"><?php print round($tempc,1) ."&deg;C " ?></div>
<?php print round($tempf,1) ?>&deg;F

<?php
		
		}
		else 
		{
			print "city not found";	
		}
	}
}
?>

</body>
</html>




For an xpath tutorial check this page.

For the next part of the workshop we used Give Me My Data to export our information from Facebook in order to revisualize it with Nodebox 1.0, a Python IDE similar to Processing.org. Here’s an example:

Update: Some user images from the workshop. Thanks all who joined!

Mutual friends (using Give Me My Data and Graphviz) by Rob Canning

identi.ca network output (starting from my username (claude) with depth 5, rendered to svg with ‘sfdp’ from graphviz) by Claude Heiland-Allen

Network graph grouping: A small art world

Thursday, December 16th, 2010

This “Mutual friends network graph” created with Nodebox using data I exported with Give Me My Data contains 540 “Facebook friends” and their connections to each other. When the graph renders it attempts to position people who have lots of connections closer together. With this you can see groups unfold based on your own social networks. Since I have spent more time in academia than I have at specific jobs my “clusters” are based mostly on my academic history.

You can also see that there are a lot of connections between my high school and where I did my undergraduate study, which is based on the fact they are located very close to each other, so friends from high school also chose the same university or town to live in. There are also a lot of interconnections between Indiana University where I did my undergrad, the University of California, San Diego, where I did graduate study, and Florida State University, where I teach now. This is probably due to the fact that my connections are all within a given field, in my case visual arts, and points to the often expressed notion that “the art world is actually very small.”

Give Me My Data updates

Wednesday, April 28th, 2010

Give Me My Data is a Facebook application that helps you reclaim and reuse your facebook data. It is currently in-development but starting to receive an amazing amount of traffic from Facebook users. Apparently the developers at Facebook made a change to the interface this week leaving many users unable to find or display specific information they had added to their pages. Give Me My Data helps users circumvent the problems they are having with the interface by giving them another way to access their data.

Due to the amount of questions I have received about the application I decided to launch a new website to share information about it here: givememydata.com

website_20100428

app_20100428
Facebook application interface

stats_20100428_map
Visitors from this week (via statcounter)

The application profile page
Use the application