Laravel Nova – Manually Send Error Alert From Observer Class

Question

I have a Season Resource model with a field named active.

The requirement is to disable deletion for a season with an active status.

I have created an Observer for the season model to watch deleting an event. From this function, I can block the delete in case active is true.

But the issue is with the error message; is there any way to add an error message to session flash from the Observer class?

<?php

public function deleting(Season $season)
{
    if($season->active_season)
    {
        Log::info('Sorry, this season can`t be deleted. 
            There must be at least one active season.');
    }

    return false;
}

Answer 1

I don't know how to flash the error message.

But since the requirement is to disable deletion for a season with an active status, I'm suggesting to use policy which won't display the delete icon when doesn't match the condition.

class SeasonPolicy {
    ...

    public function delete(User $user, Season $season) {
        if($season->active_season) {
            return false;
        }
        return true;
    }
}

and register the policy in AuthServiceProvider.

Note:

Undefined Policy Methods

If a policy exists but is missing a method for a particular action, the user will not be allowed to perform that action. So, if you have defined a policy, don't forget to define all of its relevant authorization methods.