Class exists in an external file

How do I check an external file for a class?

I am trying to setup a install feature for my modules开发者_Python百科, so I am trying to get it to load a list of directories and then check if the module file has a method called install. So only the modules with this method will be shown in the list.

Here is my code so far:

$output .= '<div id="module-dialog" title="Add Widget"><form id="widget-list" name="widget-list">

<select name="widgets" size="12" id="widgets-list">';

            $dirHandler = opendir('modules') or die ("Could not open module folder");

            while ($dir = readdir($dirHandler)) {
                if($dir!="." && $dir!=".."){
                    // Code to filter out modules with install class -- goes here
                    $output .='<option>'.$dir.'</option>';
                }
            }


 $output .='</select></form></div>';

The module file name is the same as the directory name. example: folder:Admin, file:Admin.php

If this can not be done then I guess I will create a separate file just for the install function.

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I assume you mean "How can I find out whether a PHP file defines a certain class?"

If you can include each PHP files you want to analyze

it's easy: Just compare the results of get_declared_classes() before and after the inclusion:

$before = get_declared_classes();
include "myfile.php";
$after = get_declared_classes();
$new_classes = array_diff($before, $after);
print_r($new_classes);  // Outputs all classes defined in myfile.php

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If you can't include the PHP files (e.g. because they have the same class name)

This is more tricky. If you want to do it right, the tokenizer functions can analyze a file on PHP parser level. Run a token_get_all() on your file to find out which one to look for.

If your classes follow a simple convention, simply checking for "class classname" using a regular expression might be enough.