Question

I currently have an array that hold information that a user can do. I currently use one instance of this in a dropdown menu which is very nice. What I want to do now is only include particular items if they have access to it. So say if $user_access=2 then they can do Download->small_image but not Download->large_image. I would like to be able to assign what the default access for each item in the array…even the key. So I can say a user access is 0 so they shouldn’t display “Download” at all.

I thought maybe putting the access integers for each in an object. So $access->download->small_image = 2; and then I could check one by one if an access level is greater than or equal to it and add it to the array? I’m actually not sure how I would do the loop and build up the array correctly. Another way…maybe put the access value in the actual array somehow? Any ideas would be great.

$var = array("Download" =>                                                
                   array("small_image" => "ajax_load",                         
                         "large_image" => "/master.php"),                       
                   "Page" =>                                                    
                   array("Edit" => "edit.php",                                  
                         "View" => "view.php",                                  
                         "Stuff" => "stuff.php")                                
                   );      

Answer 1

Access control is always a vague question, because there’s an unlimited amount of options. It sounds like you would be happy with an access array, IE:

array(
    0 => "root",
    10 => "Group1",
    20 => "Group2"
);

I would probably use an array for your ACL (Access Control List) also:

$ACL = array(
    "Download" => array(
        "Small_Image" => 10,
        "Large_Image" => 20
    ),
    "Page" => array(
        "Edit" => 0,
        "View" => 10
    )
);

Then call a function to authorize:

function checkACL($option, $arg, $lvl)
{
    if( $ACL[$option][$arg] >= $lvl )
        return true;
    else
        return false;
};

$userLevel = 10;
if( checkACL("Page", "Edit", $userLevel) ) {
    /*
     * Display Edit page here.
     */
} else {
    /*
     * Display "Not authorized" or redirect to a different page.
     */
}

Sorry, hope that didn’t go off topic too much.
But you can adapt that to display your menu. I’m assuming you have a login system already of coarse 🙂

if( checkACL("Download", "Small_Image", $userLevel) ) 
    echo '<a href="'.$var['Download']['Small_Image'].'">Small Image</a>';

Edit:

$var = array(
    "download.small_image" => array(
        "id"    => 1001,
        "file"  => "/img/blue.png",
        "width" => "100px",
        "height"=> "100px",
        "accessLevel"=> 20
    ),
    "page.listUsers" => array(
        "id"   => 1011,
        "file" => "/pages/list.php",
        "accessLevel" => 10
    )
);

So it works in the same principle, but all the information is centralized.
What I would do if I wasn’t using a database is store it as a json file.
You don’t want to hard code it into a php file, you want it easily modifiable.

// This will load your permissions into $var
$var = json_decode(file_get_contents("/acl.json"));

// If you design a page to modify permissions, you can save the file with this.
file_put_contents("/acl.json", json_encode($var));

// json is simple, it's basically just { "key" : "val" }