 |  |
6.11. Calling Variable Functions
6.11.2. Solution
Use variable variables:
function eat_fruit($fruit) { print "chewing $fruit."; }
$function = 'eat_fruit';
$fruit = 'kiwi';
$function($fruit); // calls eat_fruit( )6.11.3. Discussion
If you have multiple possibilities to call, use an associative array of function names:
$dispatch = array(
'add' => 'do_add',
'commit' => 'do_commit',
'checkout' => 'do_checkout',
'update' => 'do_update'
);
$cmd = (isset($_REQUEST['command']) ? $_REQUEST['command'] : '');
if (array_key_exists($cmd, $dispatch)) {
$function = $dispatch[$cmd];
$function(); // call function
} else {
error_log("Unknown command $cmd");
}This code takes the command name from a request and executes that function. Note the check to see that the command is in a list of acceptable command. This prevents your code from calling whatever function was passed in from a request, such as phpinfo( ) . This makes your code more secure and allows you to easily log errors.
Another advantage is that you can map multiple commands to the same function, so you can have a long and a short name:
$dispatch = array(
'add' => 'do_add',
'commit' => 'do_commit', 'ci' => 'do_commit',
'checkout' => 'do_checkout', 'co' => 'do_checkout',
'update' => 'do_update', 'up' => 'do_update'
);6.11.4. See Also
Recipe 5.5 for more on variable variables.
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| 6.10. Returning Failure |  | 6.12. Accessing a Global Variable Inside a Function |
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