Hello, I am trying to create a basecamp like login where users can login to see their companies projects using the url: http://abc.com/companyname/
I dont know how to create a 2 level auth... (one at the company level and another at the user level) I am new to cakePHP and I dont know how to modify the in built Auth component for my requirement.. Any help would be grateful...
I would use the Auth component for the login. I wouldn't mess with the ACL and stuff as that's pretty confusing I find.
I would approach this by adding a user_level, access_level, or permissions column in your users table. Then in here you can store a numerical value or similar.
Then in the User model, when they login using Auth you can store that value in the Auth user session object. So you can get at it using $this->Auth('User.access_level') in your controllers.
Now the Auth component by default has an isAuthorized() function in the app_controller. This function is called to see if someone has logged in. You can modify this to check that access_level and take action appropriately. I used this technique so that users can't get into the /cms routing unless they are admin = 1.
There is more information on this in the docs, http://book.cakephp.org/view/172/Authentication and you can find out more about isAuthorized() here, http://api.cakephp.org/class/auth-component#method-AuthComponentisAuthorized
Do make sure that you setup all your Auth component variables in your app_controller. Also make sure that your auth type is set to controller, and that you're allow() and deny() are configured properly.
The one big catch with all this, is that if you using a beforeFilter() in your controllers, you will need to make sure to do parent::beforeFilter() to ensure that the stuff in the app_controller is run beforehand :)
Honestly, I think that you should check out the ACL component. The book tutorial is very good if you follow it through. The major caveat is that it does not provide a mechanism for row-level access control (e.g. can user X edit this particular entry). However, it does provide a basis for doing user/group level access control, which you can then extend yourself to create the row level access you require.
In short, the ACL component supports cascading permissions (e.g. subgroups can have finely-grained access control, but otherwise inherit permissions from the parent group). That can make life a lot easier, if you need both robustness as well as granularity.
You might also check out the bakery, as there are additional auth components written by the community that may serve what you need. Highly recommended, as Auth/ACL stuff is difficult to do well, and always a major concern with web apps.