Minigalnano/rss.php

<?php 
/*==========================*/
/*Gallery address definition*/
/*==========================*/
$gallery_protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
$gallery_domain = $_SERVER['HTTP_HOST'].'/';
$gallery_path = dirname($_SERVER['REQUEST_URI']);
$gallery_link = $gallery_protocol.$gallery_domain.$gallery_path;


/*===================*/
/*Functions*/
/*===================*/
	# Hardly inspired from here : codes-sources.commentcamarche.net/source/35937-creation-d-une-arborescenceI
	# Listing all files of a folder and sub folders. 
	function ListFiles($gallery_link, &$content, $Folder, $SkipFileExts, $SkipObjects)
	{
		$dir = opendir($Folder);
		while (false !== ($Current = readdir($dir))) // Loop on all contained on the folder
		{
			if ($Current !='.' && $Current != '..' && in_array($Current, $SkipObjects)===false)
			{
				if(is_dir($Folder.'/'.$Current)) // If the current element is a folder
				{
					ListFiles($gallery_link, $content, $Folder.'/'.$Current, $SkipFileExts, $SkipObjects); // Recursivity
				}
				else
				{
					$FileExt = strtolower(substr(strrchr($Current ,'.'),1));
					if (in_array($FileExt, $SkipFileExts)===false) // Should we display this extension ?
						$current_adress = $gallery_link . "/" . $Folder.'/'. $Current;
						$content .=  $current_adress. "\n";
				}
			}
		}
		closedir($dir); 
		return $content;
	}

	# Paul's Simple Diff Algorithm v 0.1 : http://paulbutler.org/archives/a-simple-diff-algorithm-in-php/
	function diff($old, $new){
		$matrix = array();
		$maxlen = 0;
		foreach($old as $oindex => $ovalue){
			$nkeys = array_keys($new, $ovalue);
			foreach($nkeys as $nindex){
				$matrix[$oindex][$nindex] = isset($matrix[$oindex - 1][$nindex - 1]) ?
					$matrix[$oindex - 1][$nindex - 1] + 1 : 1;
				if($matrix[$oindex][$nindex] > $maxlen){
					$maxlen = $matrix[$oindex][$nindex];
					$omax = $oindex + 1 - $maxlen;
					$nmax = $nindex + 1 - $maxlen;
				}
			}   
		}
		if($maxlen == 0) return array(array('d'=>$old, 'i'=>$new));
		return array_merge(
			diff(array_slice($old, 0, $omax), array_slice($new, 0, $nmax)),
			array_slice($new, $nmax, $maxlen),
			diff(array_slice($old, $omax + $maxlen), array_slice($new, $nmax + $maxlen)));
	}

	function print_array($array_to_display) {
		echo '<pre>';
		print_r($array_to_display);
		echo '</pre>';
	}
/*===================*/
/*Variables*/
/*===================*/
	require("config.php");
	#$content = "";
	$old_files_list  = "db_old_files"; //list of files in ./photos
	$db_feed_source = "db_feed_source";
	$db_rss_timestamp = "db_rss_timestamp";
	$Folder =  'photos';
	$content = ListFiles($gallery_link, $content, $Folder, $SkipExts, $SkipObjects);
	$to_store = "";
	// Init files
	if (!file_exists($old_files_list))
	{
		file_put_contents($old_files_list, "");
	}
	if (!file_exists($db_feed_source))
	{
		file_put_contents($db_feed_source, "");
	}
	if (!file_exists($db_rss_timestamp))
	{
		file_put_contents($db_rss_timestamp, "");
	}

/*===================*/
/*Computing*/
/*===================*/
	#Todo : ajouter une condition : dois-je regénérer le flux ou utiliser les anciens fichiers ?
	$temp = file_get_contents($db_feed_source);
	$last_rss_gen = file_get_contents($db_rss_timestamp);
	$current_time = time();
	//If the RSS generation is already launched, don't do a second generation at the same time
	if (($current_time - $last_rss_gen) > $rss_refresh_interval && file_exists("rss.locker") == false)
	{	
		file_put_contents("rss.locker", "");
		file_put_contents($db_rss_timestamp, time());
		// Load the list from files.
		$old_files_list_content = explode("\n", file_get_contents($old_files_list));
		$new_files_list_content = explode("\n", $content); #debug 
		// Generate and stock new elements
		$differences = diff($old_files_list_content, $new_files_list_content);
		for ($i=0; $i < count($differences); $i++)
		{ 
			if (is_array($differences[$i]))
			{
				for ($j=0; $j < count($differences[$i]["i"]); $j++)
				{ 
					if (strlen($differences[$i]["i"][$j]) > 2)
					{
						$to_store .= $differences[$i]["i"][$j] . "\n";
					}
				}	
			}
		}
		//Add new elements at the top of the feed's source
		$temp = $to_store . $temp;
		file_put_contents($db_feed_source, $temp);
		// Store the current file list for the next generation
		file_put_contents($old_files_list, $content);
		unlink("rss.locker");
	}
/*===================*/
/*XML Gen*/
/*===================*/
	$temp = explode("\n", $temp);
	$pieceOfTitle;
	$titleLenght;
	echo "
		<rss version=\"2.0\">
			<channel>
			<title>".$title."</title>
			<link>".$gallery_link."</link>
			<description>".$description."</description>
		";
		for ($i=0; $i < $nb_items_rss; $i++) { 
			$pieceOfTitle = strrchr ($temp[$i] , "/");
			$titleLenght = strlen($pieceOfTitle) - strlen(strrchr($pieceOfTitle, "."));
			echo
				"<item>
					<title>" . substr($pieceOfTitle, 1, $titleLenght-1) . "</title>
					<link>". $temp[$i] . "</link>
					<description>
						<![CDATA[ <img src=\"" . $temp[$i] . "\"> ]]>
					</description>
				</item>"
			;
			if ($temp[$i+1] == NULL)
				break;
		}
		echo"
			</channel>
		</rss>
	";
?>