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copied!<p>I want to write a module (framework specific), that would wrap and extend Facebook PHP-sdk (<a href="https://github.com/facebook/php-sdk/" rel="nofollow noreferrer">https://github.com/facebook/php-sdk/</a>). My problem is - how to organize classes, in a nice way.</p> <p>So getting into details - Facebook PHP-sdk consists of two classes:</p> <ul> <li>BaseFacebook - abstract class with all the stuff sdk does</li> <li>Facebook - extends BaseFacebook, and implements parent abstract persistance-related methods with default session usage</li> </ul> <p>Now I have some functionality to add:</p> <ul> <li>Facebook class substitution, integrated with framework session class</li> <li>shorthand methods, that run api calls, I use mostly (through BaseFacebook::api()),</li> <li>authorization methods, so i don't have to rewrite this logic every time,</li> <li>configuration, sucked up from framework classes, insted of passed as params</li> <li>caching, integrated with framework cache module</li> </ul> <p>I know something has gone very wrong, because I have too much inheritance that doesn't look very normal. Wrapping everything in one "complex extension" class also seems too much. I think I should have few working togheter classes - but i get into problems like: if cache class doesn't really extend and override BaseFacebook::api() method - shorthand and authentication classes won't be able to use the caching. </p> <p>Maybe some kind of a pattern would be right in here? How would you organize these classes and their dependencies?</p> <p><strong>EDIT 04.07.2012</strong></p> <p>Bits of code, related to the topic:</p> <p>This is how the base class of Facebook PHP-sdk:</p> <pre><code>abstract class BaseFacebook { // ... some methods public function api(/* polymorphic */) { // ... method, that makes api calls } public function getUser() { // ... tries to get user id from session } // ... other methods abstract protected function setPersistentData($key, $value); abstract protected function getPersistentData($key, $default = false); // ... few more abstract methods } </code></pre> <p>Normaly Facebook class extends it, and impelements those abstract methods. I replaced it with my substitude - Facebook_Session class:</p> <pre><code>class Facebook_Session extends BaseFacebook { protected function setPersistentData($key, $value) { // ... method body } protected function getPersistentData($key, $default = false) { // ... method body } // ... implementation of other abstract functions from BaseFacebook } </code></pre> <p>Ok, then I extend this more with shorthand methods and configuration variables:</p> <pre><code>class Facebook_Custom extends Facebook_Session { public function __construct() { // ... call parent's constructor with parameters from framework config } public function api_batch() { // ... a wrapper for parent's api() method return $this->api('/?batch=' . json_encode($calls), 'POST'); } public function redirect_to_auth_dialog() { // method body } // ... more methods like this, for common queries / authorization } </code></pre> <p>I'm not sure, if this isn't too much for a single class ( authorization / shorthand methods / configuration). Then there comes another extending layer - cache:</p> <pre><code>class Facebook_Cache extends Facebook_Custom { public function api() { $cache_file_identifier = $this->getUser(); if(/* cache_file_identifier is not null and found a valid file with cached query result */) { // return the result } else { try { // call Facebook_Custom::api, cache and return the result } catch(FacebookApiException $e) { // if Access Token is expired force refreshing it parent::redirect_to_auth_dialog(); } } } // .. some other stuff related to caching } </code></pre> <p>Now this pretty much works. New instance of Facebook_Cache gives me all the functionality. Shorthand methods from Facebook_Custom use caching, because Facebook_Cache overwrited api() method. But here is what is bothering me:</p> <ul> <li>I think it's too much inheritance. </li> <li>It's all very tight coupled - like look how i had to specify 'Facebook_Custom::api' instead of 'parent:api', to avoid api() method loop on Facebook_Cache class extending.</li> <li>Overall mess and ugliness.</li> </ul> <p>So again, this works but I'm just asking about patterns / ways of doing this in a cleaner and smarter way.</p>

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