Need guidance to start with Zend ACL

Question

I am currently working on a site that requires ACL and as I am using Zend, it makes sense for me to make use of their ACL class but I have little to zero idea of how to do t

Answer 1

I implemented similar thing not so long ago. Basic concept follows in an example code.

I created my own configAcl.php file which is loaded in bootstrap file, in my case it is index.php. Here is how it'd be according to your case:

$acl = new Zend_Acl();

$roles  = array('admin', 'normal');

// Controller script names. You have to add all of them if credential check
// is global to your application.
$controllers = array('auth', 'index', 'news', 'admin');

foreach ($roles as $role) {
    $acl->addRole(new Zend_Acl_Role($role));
}
foreach ($controllers as $controller) {
    $acl->add(new Zend_Acl_Resource($controller));
}

// Here comes credential definiton for admin user.
$acl->allow('admin'); // Has access to everything.

// Here comes credential definition for normal user.
$acl->allow('normal'); // Has access to everything...
$acl->deny('normal', 'admin'); // ... except the admin controller.

// Finally I store whole ACL definition to registry for use
// in AuthPlugin plugin.
$registry = Zend_Registry::getInstance();
$registry->set('acl', $acl);

Another case is if you want to allow normal user only "list" action on all your controllers. It's pretty simple, you'd add line like this:

$acl->allow('normal', null, 'list'); // Has access to all controller list actions.

Next you should create new plugin which takes care of credential checking automatically when there is a request for some controller action. This checking takes place in preDispatch() method that is called before every call to the controller action.

Here is AuthPlugin.php:

class AuthPlugin extends Zend_Controller_Plugin_Abstract
{
    public function preDispatch(Zend_Controller_Request_Abstract $request)
    {
        $loginController = 'auth';
        $loginAction     = 'login';

        $auth = Zend_Auth::getInstance();

        // If user is not logged in and is not requesting login page
        // - redirect to login page.
        if (!$auth->hasIdentity()
                && $request->getControllerName() != $loginController
                && $request->getActionName()     != $loginAction) {

            $redirector = Zend_Controller_Action_HelperBroker::getStaticHelper('Redirector');
            $redirector->gotoSimpleAndExit($loginAction, $loginController);
        }

        // User is logged in or on login page.

        if ($auth->hasIdentity()) {
            // Is logged in
            // Let's check the credential
            $registry = Zend_Registry::getInstance();
            $acl = $registry->get('acl');
            $identity = $auth->getIdentity();
            // role is a column in the user table (database)
            $isAllowed = $acl->isAllowed($identity->role,
                                         $request->getControllerName(),
                                         $request->getActionName());
            if (!$isAllowed) {
                $redirector = Zend_Controller_Action_HelperBroker::getStaticHelper('Redirector');
                $redirector->gotoUrlAndExit('/');
            }
        }
    }
}

Final steps are loading your configAcl.php and register the AuthPlugin in bootstrap file (probably index.php).

require_once '../application/configAcl.php';

$frontController = Zend_Controller_Front::getInstance();
$frontController->registerPlugin(new AuthPlugin());

So this is the basic concept. I didn't test the code above (copy and paste and rewrite just for the showcase purpose) so it's not bullet-proof. Just to give an idea.

EDIT

For the clarity. The code above in AuthPlugin suppose that the $identity object is filled with user data ("role" column in the database). This could be done within the login process like this:

[...]
$authAdapter = new Zend_Auth_Adapter_DbTable($db);
$authAdapter->setTableName('Users');
$authAdapter->setIdentityColumn('username');
$authAdapter->setCredentialColumn('password');
$authAdapter->setIdentity($username);
$authAdapter->setCredential(sha1($password));
$authAdapter->setCredentialTreatment('? AND active = 1');
$auth = Zend_Auth::getInstance();
$result = $auth->authenticate($authAdapter);
if ($result->isValid()) {
    $data = $authAdapter->getResultRowObject(null, 'password'); // without password
    $auth->getStorage()->write($data);
[...]