Web 2.0 was all about mashups and data api’s !, Some of the popular ones are google search api , twitter api etc.
All API’s have some rate-limiting , For example Twitter API has a rate limit of 150 requests per hour ! , Yahoo API and Google API’s have a daily limit on their requests.
The ultimate method of getting over this API request limit is to make a cache method which stores all data that is coming from API , Which you can refresh hourly, weekly or daily !
That’s why i created a small function to store the API data in a xml cache file , Which can be later on retrieved to get data.Find that function below, Most of the functionality is explained in the comments , If anything is not clear contact me via contact page.
< ?php
function get_yahoo_data_cached($query, $zip) {
// Rewrite by Julius Beckmann
// Remove dangerous chars
$query_safe = str_replace(array('.','/'), '_', $query);
$zip_safe = str_replace(array('.','/'), '_', $zip);
$cache_filename = "cache/$query_safe-$zip_safe.xml";
$time_expire = time() + 24*60*60; // Expire Time (1 Day)
// Check file change time
if(filectime($filename) <= $time_expire) {
// File is too old, refresh cache
$xml = get_yahoo_data($query, $zip);
// Remove cache file on error to avoid writing wrong xml
if($xml)
file_put_contents($cache_filename, $xml);
else
unlink($cache_filename);
}else{
// Fetch cache
$xml = file_get_contents($cache_filename);
}
return $xml;
}
?>
Safe rewrite of the function by Julius Beckmann
This function creates a cache file for yahoo api requests , here we are using get_yahoo_data() function to fetch data from yahoo api which is a custom function for extracting data from yahoo api and throwing that in xml output format.
If we do a small synopsis of the above function we can see that it uses 2 variables to store cache , $filename stores the cache file and $file_log_name stores the last update time for that cache !
