Conditional StateConfig

[goldjunge4]

Hello,
i am using laravel model states since a longer time, but know i have the request, that i have a different StateConfig (different States) based on an user or a field value? Is there a way to achieve this?
Thanks

[lukas-staab]

The question is a bit old, but maybe someone else is intrested:

I have solved it with Policies, which have to be authorized on the controler route anyway. There might be ways to achieve it with custom transitions, but I thought it would become to entangled to solve it inside the state machine provided by the lib.

[devantoine]

Can you show your implementation @lukas-staab?

[lukas-staab]

I did something like this (slightly simplified from my original, so maybe not 1:1 runable)

class ProjectPolicy
{
    use HandlesAuthorization;

    public function viewAny(User $user): bool
    {
        return true; // everyone can view
    }

    public function view(User $user, Project $Projects): bool
    {
        return true; // everyone can view any project
    }

    public function create(User $user): bool
    {
        return true; // everyone can create
    }

    public function update(User $user, Project $project): bool
    {
       // only some UserGroups can edit, depending on the state, that are different ones 

        $userGroups = $user->getGroups();
        $canChangeA = $userGroups->contains('group-a');
        $canChangeB = $userGroups->contains('group-b');

        return match ($project->state::class) {
            Draft::class => true,
            Applied::class => $canChangeA,
            Terminated::class => $canChangeB,
            default => false,
        };
    }

    public function delete(User $user, Project $Projects): bool
    {
        // TODO
    }

    public function createExpense(User $user, Project $project): bool
    {
        return $project->state->expensable();
    }

    public function transitionTo(User $user, Project $project, ProjectState $newState): bool
    {
       // only some usergroups can transition into specific states

        $currentState = $project->state;

        $isOwner = $user->id === $project->creator->id;
        $userGroups = $user->getGroups();

        $processor  = $userGroup->contains('group-a');
        $terminator = $userGroups->contains('group-b');

        // for me the needed permission is only
        // defined by the new state, the current one is irrelevant
        return match ($newState::class) {
            Draft::class => $isOwner,
            Applied::class => $isOwner || $processor,
            Terminated::class => $isOwner || $terminator,

            default => false,
        };
    }
}

and in the Controller:

class ProjectController extends Controller
{
    
    /**
     * Store a newly created resource in storage.
     */
    public function storeStateChange(Request $request, Project $project)
    {
        // sanitize input and define variables
        ...
        // check if state change is definied in the StateConfig
        if (! $currentState->canTransitionTo($newState)) {
            return false;
        }
        // check if user is allowed to do that change 
         Gate::authorize('transition-to', [$project, $newState]);

       // save state change 
       ...
    }

    /**
     * Display the specified resource.
     */
    public function show(Project $project)
    {
        Gate::authorize('view', $project);

        return view('project.show', compact('project'));
    }

   
}

checkout the laravel documentation for Policies and Gates for further information on them. I decided to do the buisness logic (is state change possible) in the controller and the check if it is allowed via a Policy / Gate. You can reuse the Policy via @can() in blade, if you do that you might want to double check there as well that the transition is defined. But thats up to your taste I guess.

In your case you could do 2 different Policies or 2 different Methods, and you call one in Controller A and anotherone in Controller B

[devantoine]

I'm needing something similar, I'd like to be able to contextualize transitions.

For instance when I'm in controller A, all transitions are allowed while in controller B only some of them.