Bitwiser

Bitwiser is a utility class to help managing bitwise flags.

Bitwise flags are a convenient way to store multiple true/false values (flags) in a single integer based database column. The number of bitwise flags are however limited to the maximum value of an integer of the system (which is 64 on a 64bit system or 32 on a 32bit system).

Example usage

Create a class that extends AbstractBitwiser and declare the flags as class constants.

class PermissionsBitwiser extends AbstractBitwiser
{
constCAN_EDIT_POSTS = 0;
constCAN_DELETE_POSTS = 1;
constCAN_CREATE_USERS = 2;
}

Initialize the class with a starting state and callback

$state = 0; // this value is passed by reference$permissions = newPermissionsBitwiser($state, function (AbstractBitwiser$bitwiser) {
echo$bitwiser->getState();
});
$permissions->add(PermissionsBitwiser::CAN_EDIT_POSTS); // echoes 1$permissions->add(PermissionsBitwiser::CAN_DELETE_POSTS); // echoes 3$permissions->add(PermissionsBitwiser::CAN_CREATE_USERS); // echoes 7$permissions->remove(PermissionsBitwiser::CAN_DELETE_POSTS); // echoes 5$permissions->getState(); // int(5)$permissions->has(PermissionsBitwiser::CAN_EDIT_POSTS); // true$permissions->has(PermissionsBitwiser::CAN_DELETE_POSTS); // false

Example usage with ORM (eg. Laravel Eloquent) for persisitence

The end goal is to persist the integer value to a database column while maintaining a clean OO method of updating the value.

class User extends Model
{
publicfunctiongetPermissionsAttribute()
{
$state = $this->attributes['permissions']; // Don't pass this by reference$self = $this;
returnnewPermissionsBitwiser($state, function ($bitwiser) use ($self) {
$self->permissions = $bitwiser->getState();
});
}
}
$user = newUser;
$user->permissions->add(PermissionsBitwiser::CAN_CREATE_USERS);
$user->save();
$user->permissions->has(PermissionsBitwiser::CAN_DELETE_POSTS); // false$user->permissions->has(PermissionsBitwiser::CAN_CREATE_USERS); // true. etc