11 May 2023
Error: Class name must be a valid object or a string in file … HasRelationships.php
in config/auth.php add this to the guards array
'sanctum' => [
'driver' => 'sanctum',
'provider' => 'users'
],
This error occurs when attempting to eager load roles with their assigned users from Spatie’s laravel-permissions library like this
<?php
use Spatie\Permission\Models\Role;
Role::with('users')->get();
What can be more confusing is that this code works fine in the Laravel PsySH powered Repl Tinker, see this StackOverflow post
The problem is that if you’re using the first party Sanctum package, its service provider sets an authentication guard with a null value for the provider, see source code here
class SanctumServiceProvider extends ServiceProvider
{
/**
* Register any application services.
*
* @return void
*/
public function register()
{
config([
'auth.guards.sanctum' => array_merge([
'driver' => 'sanctum',
'provider' => null, // <=== This is the issue
], config('auth.guards.sanctum', [])),
]);
if (! app()->configurationIsCached()) {
$this->mergeConfigFrom(__DIR__.'/../config/sanctum.php', 'sanctum');
}
}
This causes Laravel-Permission’s getModelForGuard() helper function here
function getModelForGuard(string $guard)
{
return collect(config('auth.guards'))
->map(fn ($guard) => isset($guard['provider']) ? config("auth.providers.{$guard['provider']}.model") : null)
->get($guard);
}
to return nothing when middleware requires the Sanctum guard to be authenticated, hence the eager load fails here
<?php
/**
* A role belongs to some users of the model associated with its guard.
*/
public function users(): BelongsToMany
{
return $this->morphedByMany(
// Error occurs here
getModelForGuard($this->attributes['guard_name'] ?? config('auth.defaults.guard')),
'model',
config('permission.table_names.model_has_roles'),
app(PermissionRegistrar::class)->pivotRole,
config('permission.column_names.model_morph_key')
);
}
After manually inserting the guard in auth/config.php with a proper provider, eager loading works again
'guards' => [
...
'sanctum' => [
'driver' => 'sanctum',
'provider' => 'users'
]
],
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