Cache Remote JSON Feed

readme.txt

HOW IT WORKS

The function takes two arguments:

The $cache_file argument stores the server location of the cache file you wish to use. By default it will look for api-cache.json in the same directory as the script using this function.

The $expires argument will store the time between each API request. By default a new API request will be made every 2 hours.
You’ll need to create the cache file with CHMOD 777 permissions before this function will work. The function will check to see if the cache file exists using file_exists(), throwing an error message if it does not. If the cache file exists, the script will check to see if it’s empty using file_get_contents(). If it is empty an initial API request is made and the results are stored as JSON in the cache file using file_put_contents(). If the cache file exists and is not empty the script will check the last time the file was modified using filectime(). If it was modified longer than the $expires time an API request is made and the file is updated.

cache-json.php

<?php

/**
 * API Request Caching
 *
 *	Use server-side caching to store API request's as JSON at a set 
 *	interval, rather than each pageload.
 * 
 * @arg Argument description and usage info
 */


function json_cached_api_results( $cache_file = NULL, $expires = NULL ) {
	global $request_type, $purge_cache, $limit_reached, $request_limit;
 
	if( !$cache_file ) $cache_file = dirname(__FILE__) . '/api-cache.json';
	if( !$expires) $expires = time() - 2*60*60;
 
	if( !file_exists($cache_file) ) die("Cache file is missing: $cache_file");
 
	// Check that the file is older than the expire time and that it's not empty
	if ( filectime($cache_file) < $expires || file_get_contents($cache_file)  == '' || $purge_cache && intval($_SESSION['views']) <= $request_limit ) {
 
		// File is too old, refresh cache
		$api_results = indeed_api_request();
		$json_results = json_encode($api_results);
 
		// Remove cache file on error to avoid writing wrong xml
		if ( $api_results && $json_results )
			file_put_contents($cache_file, $json_results);
		else
			unlink($cache_file);
	} else {
		// Check for the number of purge cache requests to avoid abuse
		if( intval($_SESSION['views']) >= $request_limit ) 
			$limit_reached = " <span class='error'>Request limit reached ($request_limit). Please try purging the cache later.</span>";
		// Fetch cache
		$json_results = file_get_contents($cache_file);
		$request_type = 'JSON';
	}
 
	return json_decode($json_results);
}

example.php

<?php
/**
 * Format a basic job listing in HTML5
 */
function indeed_job_results( $api_results = NULL, $search = NULL ) {
	if( !$api_results ) return false;
 
	$total = count($api_results);
	$search = ( $search ) ? " found for &ldquo;<strong>$search</strong>&rdquo;" : "";
 
	$html = "<section class='jobs'>";
	$html .= "<header>";
	$html .= "<h2>$total jobs$search</h2>";
	$html .= "</header>";
	foreach ( $api_results as $job ) {
		$date = explode(' ', $job->date);
		$formattedDate = $date[2] . ' ' . $date[1] . ', ' . $date[3];
 
		$html .= "<article>";
		$html .= "<h3><a href='{$job->url}' target='_blank'>{$job->jobtitle}</a></h3>";
		$html .= "<p class='details'>{$job->formattedLocation} <em>&ndash;</em> $formattedDate</p>";
		$html .= "</article>";
	}
	$html .= "</section><!--// end .jobs -->";
 
	return $html;
}


//Using the function in practice is simple:

$api_results = json_cached_api_results();
$jobs_output = indeed_job_results( $api_results, 'Google' );