PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Solution Overview
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}
if($type == 'browse') {
$ars->browseNodeSearch($parameters['browsenode'], $parameters['page'],
$parameters['mode']);
}
if($type == 'search') {
$ars->keywordSearch($parameters['search'], $parameters['page'],
$parameters['mode']);
}
cache($type, $parameters, $ars);
}
return $ars;
All the application’s SOAP or XML caching is done via this function.You also use
another function to cache images.You begin by calling the cached() function to see
whether the required AmazonResultSet is already cached. If it is, you return that data
instead of making a new request to Amazon:
$cache = cached($type, $parameters);
if($cache) // if found in cache{
return $cache;
}
If not, when you get the data back from Amazon, you add it to the cache:
cache($type, $parameters, $ars);
Let’s look more closely at these two functions: cached() and cache().These functions,
shown in Listing 33.12, implement the caching Amazon requires as part of its terms and
conditions.
Listing 33.12 cached() and cache() Functions—Caching Functions from
cachefunctions.php
// check if Amazon data is in the cache
// if it is, return it
// if not, return false
function cached($type, $parameters) {
if($type == 'browse') {
$filename = CACHE.'/browse.'.$parameters['browsenode'].'.'
.$parameters['page'].'.'.$parameters['mode'].'.dat';
}
if($type == 'search') {
$filename = CACHE.'/search.'.$parameters['search'].'.'
.$parameters['page'].'.'.$parameters['mode'].'.dat';
}
if($type == 'asin') {
$filename = CACHE.'/asin.'.$parameters['asin'].'.'
.$parameters['mode'].'.dat';