A cute little cachable class method implementation

gistfile1.php

<?php
// Example:

$data_from_api = LibraryOfCachableFunctions::get_some_data_from_api( $args );

// LibraryOfCachableFunctions does not have a get_some_data_from_api() function.
// This causes __callStatic() to be called. __callStatic() takes care of caching.
// if the results are not available in the cache, it calls a function by adding an underscore to the name of the called function.
// the _get_some_data_from_api() function is used to obtain the results and store them in the cache.

// You can add any other cachable function simply by creating a function whose name starts with an underscore.


define( 'DEFAULT_CACHE_DURATION', 10 );

class LibraryOfCachableFunctions {
  private static $cache_durations_in_minutes = array(
    'get_some_data_from_api' => 60,
  );
  
  public static function __callStatic( $function_name, $arguments ) {
    $cache_key = md5( $function_name . '?' . http_build_query( $arguments ) );
    
    if ( cache_has( $cache_key ) {
      return get_from_cache( $cache_key );
    } else {
      $data = call_user_func_array( array( 'self', '_' . $function_name ), $arguments );
      $cache_duration = isset( self::$cache_durations_in_minutes[ $function_name ] ) ? self::$cache_durations_in_minutes[ $function_name ] : DEFAULT_CACHE_DURATION;
      put_in_cache( $cache_key, $data, $cache_duration );
      
      return $data;
    }
  }
  
  private static function _get_some_data_from_api( $args ) {
    // actually go to API
    return array( '42' );
  }
}

function cache_has( $key ) {
  return false;
}

function get_from_cache( $key ) {
  return null;
}

function put_in_cache( $key, $data, $duration_in_minutes ) {
  return 'OK';
}