gistfile1.php

<?php
	# Settings
	// URL for all releases
	$all_url = 'http://concordiarx.mediaroom.com/api/newsfeed_releases/list.php';
	// URL template for a release (later ID is appended to the URL)
	$single_url = 'http://concordiarx.mediaroom.com/api/newsfeed_releases/get.php?id=';
	// Enable cache for test purposes (files will be downloaded just once). Set to false in production
	$cache = true;
	// Cache directory
	$cache_dir = 'cache/';
	// Output type:
	//	empty string -> echo to the browser
	//	'path/filename.xml' -> save as file on server
	$output = 'result.xml';
	// Pause time between requests (in seconds)
	$pause_time = 1;
	// Maximum run time
	$time_limit = 60;
	set_time_limit($time_limit);


	# Logic
	// Check if allow_url_fopen is enabled
	if( !ini_get('allow_url_fopen') ){
		die("Please enable 'allow_url_fopen' option in your php.ini file.");
	}

	// Create cache directory if not exists
	if( $cache && !is_dir($cache_dir) ){
		mkdir($cache_dir) or die('Cannot create cache dir.');
	}


	// Cache file for all realeses feed
	$cache_file = $cache_dir . 'all.xml';

	// Load the XML from cache or refresh from URL
	if( !$cache or !file_exists($cache_file) ){
		$all = file_get_contents($all_url);
		file_put_contents($cache_file, $all);
		sleep($pause_time);
	}else{
		$all = file_get_contents($cache_file);
	}

	// DOMDocument for reading all releases data
	$all_dom = new DOMDocument();
	$all_dom->loadXML($all) or die('Error loading all releases feed.');
	// XPath instance for extracting data from all releases feed
	$xpath = new DOMXPath($all_dom);

	// DOMDocument for resulting feed
	$result_dom = new DOMDocument('1.0', 'UTF-8');

	// Append <releases> element to XML
	$result_releases = new DOMElement('releases');
	$result_dom->appendChild($result_releases);

	// Append the meta info from all releases feed
	$result_releases->appendChild(new DOMElement('matching_count', $xpath->query('//releases/matching_count')->item(0)->nodeValue));
	$result_releases->appendChild(new DOMElement('returned_count', $xpath->query('//releases/returned_count')->item(0)->nodeValue));
	$result_releases->appendChild(new DOMElement('latestModified', $xpath->query('//releases/latestModified')->item(0)->nodeValue));

	// Find all release IDs and fetch the result
	foreach($xpath->query('//release/id') as $id){
		// ID of the release
		$id = $id->nodeValue;
		// URL of release feed
		$url = $single_url . $id;
		// Cache file for release feed
		$cache_file = $cache_dir . $id . '.xml';

		// Load from cache or refresh from URL
		if( !$cache or !file_exists($cache_file) ){
			$single = file_get_contents($single_url . $id);
			file_put_contents($cache_file, $single);
			sleep($pause_time);
		}else{
			$single = file_get_contents($cache_file);
		}

		// DOMDocument for release feed
		$single_dom = new DOMDocument();
		$single_dom->loadXML($single) or die('Error loading release from ' . $url);
		// Get <release> tag
		$target_node = $single_dom->getElementsByTagName('release')->item(0);

		// Clone the <release> tag and it's childs and append to resulting feed
		$result_releases->appendChild($result_dom->importNode($target_node, true));
	}

	if( $output ){
		// Save as file on disk
		$result_dom->save($output);
	}else{
		// Output to the browser
		header('Content-type: text/xml');
		header('Content-encoding: UTF-8');
		echo $result_dom->saveXML();
	}

?>