flickr_random_group_image.php

<?
// Settings
$groups = array(
	'71332142@N00', 	# catchy colours
	'1949459@N23', 		# nikon
	'83812269@N00', 	# nightlife
	'52239829790@N01', 	# subsets
	'52239733174@N01', 	# B&W
	'42097308@N00', 	# less is more
	'52240257802@N01', 	# long exposure
);
$flickrapi 		= '####################';
$cache 			= __DIR__."/flickr.cache"; // make this file in same dir
$force_refresh		= false; // dev
$refresh		= 60*60*24; // once a day

// cache api results so to not over-query (api restrictions)
if ($force_refresh  || isset($_GET['refresh_flickr']) || ((time() - filectime($cache)) > ($refresh) || 0 == filesize($cache))) {
	
	// were freshing the feed, select a random group from pool
	$groupc = count($groups)-1;
	$random_group = rand(0,$groupc);
	
	// setup flickr url
	$params = array(
		'api_key'	=> $flickrapi,
		'id' 		=> $groups[$random_group],
		'lang' 		=> 'en-us',
		'format'	=> 'php_serial',
	);
	$encoded_params = array();
	foreach ($params as $k => $v)
		$encoded_params[] = urlencode($k).'='.urlencode($v);
	$url = "https://api.flickr.com/services/feeds/groups_pool.gne?".implode('&', $encoded_params);

	// get api results
	$ch = curl_init($url) or die("curl issue");
	$curl_options = array(
		CURLOPT_RETURNTRANSFER	=> true,
		CURLOPT_HEADER 		=> false,
		CURLOPT_FOLLOWLOCATION	=> false,
		CURLOPT_ENCODING	=> "",
		CURLOPT_AUTOREFERER 	=> true,
		CURLOPT_CONNECTTIMEOUT 	=> 7,
		CURLOPT_TIMEOUT 	=> 7,
		CURLOPT_MAXREDIRS 	=> 3,
		CURLOPT_SSL_VERIFYHOST	=> false,
		CURLOPT_USERAGENT	=> "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.A.B.C Safari/525.13"
	);
	curl_setopt_array($ch, $curl_options);
	$curlcontent = curl_exec( $ch );
	curl_close( $ch );
	
	// write results to cache
	$handle = fopen($cache, 'wb') or die('no fopen');	
	$flickr_cache = $curlcontent;
	fwrite($handle, $flickr_cache);
	fclose($handle);
} else {
	$flickr_cache = file_get_contents($cache); //locally
}

$stream = unserialize($flickr_cache);

// show a random photo from the group (stream defaults at 20 items)
// change this var to `0` to keep a single image for $refresh duration
$show = rand(0,19);

echo $stream['items'][$show]['photo_url']."?date=".date('Y-m-d',strtotime($stream['items'][$show]['date_taken_nice']))."&group=".a_n($stream['title']);
?>