Autoload php classes from subfolders using underscores (PEAR style)

Question

I'm a little new to object oriented PHP and MVC, so I really need help.

I have a MVC style folder structure with subfolders in the file system
- eg. view/classes/subfolder/classname.php

I use mod_rewrite for human-friendly URLs like /classname or /foldername/calssname , which are then passed to the page loader as an underscore of shared values.
- eg. foldername_classname

  // Page Loader File
 require_once ($ _ SERVER ['DOCUMENT_ROOT']. '/ local / classLoader.php');
 session_start ();
 $ page = new $ _REQUEST ['page'];

I previously used the [if / else if / else] block to test in every possible folder, but this seems inefficient, so I'm looking for the best way to find the autoloader in many different places.

Here is my last glitch that none of the requested classes can be found and simply throws an exception for each, ending with a fatal error !:

  function classToPath ($ class) {
     $ path = str_replace ('_', '/', $ class).  '.php';
     return $ path;
 }

 function autoloadController ($ class) {
     echo 'LoadController'. ' 
  ';
     $ root = '/ controller / classes /';
     $ pathtoclass = $ root.classToPath ($ class);

     try {
         if (file_exists ($ pathtoclass)) require_once ($ pathtoclass);
         else throw new Exception ('Cannot load controller'. $ class);
     } catch (Exception $ e) {
         echo 'Controller exception:'.  $ e-> getMessage ().  " 
  ";
     }
 }

 function autoloadModel ($ class) {
     echo 'LoadModel'. ' 
  ';
     $ root = '/ model / classes /';
     $ pathtoclass = $ root.classToPath ($ class);

     try {
         if (file_exists ($ pathtoclass)) require_once ($ pathtoclass);
         else throw new Exception ('Cannot load model'. $ class);
     } catch (Exception $ e) {
         echo 'Model exception:'.  $ e-> getMessage ().  " 
  ";
     }
 }

 function autoloadView ($ class) {
     echo 'LoadView'. ' 
  ';
     $ root = '/ view / classes /';
     $ pathtoclass = $ root.classToPath ($ class);

     try {
         if (file_exists ($ pathtoclass)) require_once ($ pathtoclass);
         else throw new Exception ('Cannot load view'. $ class);
     } catch (Exception $ e) {
         echo 'View exception:'.  $ e-> getMessage ().  " 
  ";
     }
 }

 spl_autoload_register ('autoloadController');
 spl_autoload_register ('autoloadModel');
 spl_autoload_register ('autoloadView');

---

I was also interested to know how the URL should work for folder / class mapping:
- i.e. URL: /foldername/classname mod_rewritten to foldername_classname ;
with the class file name classname.php in the foldername folder;
and php class foldername_classname extends another_class { etc.

Is this the correct method?

Answer 1

Rather, by chance, referring to another issue , I found a solution to my problem !

So, to answer my own questions (and hopefully help others):

• the file name should only be the last part of the url
  ie .../not-this-part/but-this
• folder structure must be a URL structure map
  e.g. .../folder/subfolder/class
• and the class should be defined as the full path, but with underscores instead of skew
  e.g. class folder_subfolder_class {

Then I wrote a function for each class system (model, view, and controller) and used spl_autoload_register() to register each function as a __autoload function. Thus,...

  function loadController ($ class) {
     $ path = $ _SERVER ['DOCUMENT_ROOT']. '/ application / controller /';
     $ filename = str_replace ('_', DIRECTORY_SEPARATOR, strtolower ($ class)). '. php';

     if (file_exists ($ path. $ filename)) {
         require_once ($ path. $ filename);
     }
 }
 etc..etc ..
 spl_autoload_register ('loadController');
 ...

For those who are wondering about the mod_rewrite part ...

  IfModule mod_rewrite.c
     Rewriteengine on

     RewriteBase /

     RewriteCond% {SCRIPT_FILENAME}! -F
     RewriteCond% {SCRIPT_FILENAME}! -D

     RewriteRule ^ ([az] +) / ([az] +) /? $ /? Page = $ 1_ $ 2 [QSA, NC, L]
     RewriteRule ^ ([az] +) /? $ /? Page = $ 1 [QSA, NC, L]
 / IfModule