Simple PHP Caching and Content Retrieval Function

Discussion

1. Hervé

   Why don’t you simply use something simple like pear cache lite ?
2. Michael

   Hi,
   ever thought about memcached? Its a nice daemon, which can store such things in memcache, its very easy to usw and very efficient. Many big sites use it, facebook has about 800 Memcached-Servers.
3. Chris the Developer

   @herve + michael: Simply put, this approach allows the developer to cache without having to set the environment up to use memcache or pear cache lite….
4. Brandon

   Thank you! I was looking for something like this yesterday. Exactly what I needed.
5. redwall_hp

   Basic caching like this is really useful when dealing with APIs, but I wish WordPress would add some centralized caching functions. It would make things neater than dumping data into assorted wp_options fields…
6. Spyros

   I must say that i like this blog very much. I’m pretty interested in mootools because i’m in the process of creating javascript UIs. This tutorial is also very nice. It’s a good habit to cache whatever is possible.
7. Nickolas Simard

   Nice function.
   I’ll be looking to build something similar, but with images created dynamically… Check if image exist and check if image is “recent”… else regenerate the image.

   I allready did something similar with an XML generator, so users cannot spam the website to generate a new XML every time.

   Caching is something useful when controlled… but can be a pain when you don’t know stuff is cached (ka-Map comes to mind…)!
8. Covi

   Zend Framework (Zend_Http & Zend_Cache) ^^!

   And… a few small suggestions:

   * is_file instead file_exists: No warnings and not @ supress errors operator.
   * strtotime(‘text’) instead calculate hours: More intuitive.
   * register_shutdown_function for caching new content, after
   the first petition and the file creation if not exists: No delay, no http errors for dump the file content.

   I used this at betools.culturadigital.org ;)
9. mylife

   I am working on a job site wordpress, I want to pull user linkedin profile details with image and appear that on site, when anonymous user submit linkedin public url in the wordpress registration form, their profile header content should fetch on the site.

   This should work for anonymous user, every time new user put his linked-in profile URL, so this should not use that only for single user.

   hope you get what I need. please help if somebody have such function in php for wordpress site.

   waiting……….

   thanks
10. João Verissimo Ribeiro

    Here is class of caching the full page:
    https://github.com/joaoverissimo/SimpleCachePhp

    thanks
11. Lazza

    David, thank you very much for this, that’s exactly what I was looking for. :)
12. Will Smelser

    You gave a good starting place, but a nice feature which you are missing is to save yourself some IO if the response headers say the file has not been altered:

    public static function get_content($url) {
            //vars
            $file = self::$cachDir . md5($url);
            $currentTime = time();
            $expireTime = self::$expireMin * 60;
            $fileTime = filetime($file);
    
            $content = '';
    
            //decisions, decisions
            if(file_exists($file) && ($currentTime - $expireTime  $fileTime){
                    file_put_contents($file,$content);
                //document has not been modified, lets update the file's time
                }else{
                    touch($file);
                }
    
            }
            else {
                $content = file_get_contents($url);
                file_put_contents($file,$content);
            }
    
            return $content;
        }
    
13. stewart

    Hi

    that’s brilliant, wanted a way to cache files without using ob_start(),ob_get_contents()

    u just saved me ages of time messing around coding

    thank you David
14. cartman

    @Will Smelser: what the hell … your code is messed up and semantically and logically wrong
15. Andy

    I had some problems with this caching function when trying to use json_decode() on the returned result, for some reason it was not being recognised.

    I removed the cached text from the file and everything works fine!

    Andy
    Web Canvas Design
• Josh

  Thanks, Andy, this is exactly what I was trying to figure out.
16. crabtronic

    Hello, is it possible to get content from any site then check if adress is the same and so add a checkmark in the row of the user in the backoffice user page ?
17. Josh

    Thank you very much for this. This helped me out tremendously!
18. David Spector

    A different approach is appropriate for doing development work. All the PHP file system functions do their own caching, and you can use the realpath_cache_size = 0 directive in PHP.ini to disable the caching if you like. The default caching timeout is 120 seconds. This is separate from the caching typically done by browsers for all GET requests (the majority of Web accesses) unless the HTTP headers override it. Caching is not a good idea during development work, since your code may read in old data from a file whose contents you have changed.
19. David Spector

    Correction (these postings can’t be edited and the avatars can’t be chosen!): to disable the PHP file contents cache, use the directive realpath_cache_ttl = 0 in the PHP.ini file.