Yep, not sure how to get around that yet.

No problem. Thanks for all of your help!

Did you ever get a solution to this? I have the same problem - adding manually to database allows me to update, but I can't create a new user, edit a user unless without there being an existing entry in the new table.

Hello Adam,

Unfortunately I didn't get solution yet... :(

I came across this forum post and wanted to share what worked for me. I kept getting a null reference on save, and found that I needed to instantiate an instance of my model if it did not exist for both create and update.

Plugin.php:

public function boot()
    {
        // hook in to Form model and add our relationship to SimpleTicket table
        Form::extend(function ($model) {
            $model->hasOne['simpleticket'] = [SimpleTicket::class, 'key' => 'form_id'];

            // hook in to form delete to clean up associated simpleticket records
            $model->bindEvent('model.afterDelete', function() use ($model) {
                $st = SimpleTicket::where('form_id', $model->id);
                if ($st) {
                    $st->delete();
                }
            });
        });

        // extend the Form Builder admin to show the SimpleTicket options
        Event::listen('backend.form.extendFields', function($widget) {
            // Only for the Form Builder - Edit Form screen
            if (!$widget->getController() instanceof Forms) {
                return;
            }

            // Only for the Form model
            if (!$widget->model instanceof Form) {
                return;
            }

            // if we are doing a create, we need to attach an empty simpleticket to the widget model
            // this prevents a null relationship on save
            if ($widget->getContext() == 'create' || $widget->getContext() == 'update') {
                if (!$widget->model->simpleticket) {
                    $widget->model->simpleticket = new SimpleTicket();
                }
            }

            // Add SimpleTicket tab and fields
            $widget->addTabFields([
                'simpleticket[enabled]' => [
                    'label' => 'Enable SimpleTicket integration',
                    'comment' => 'Sends the form to a SimpleTicket instead of email',
                    'tab' => 'SimpleTicket',
                    'type' => 'checkbox',
                    'span' => 'full'
                ],
                'simpleticket[ticket_type]' => [
                    'label' => 'Ticket Type',
                    'comment' => 'The SimpleTicket ticket type',
                    'tab' => 'SimpleTicket',
                    'type' => 'text',
                    'span' => 'auto'
                ],
                'simpleticket[problem_type]' => [
                    'label' => 'Problem Type',
                    'comment' => 'The SimpleTicket problem type',
                    'tab' => 'SimpleTicket',
                    'type' => 'text',
                    'span' => 'auto'
                ],
                'simpleticket[created_by]' => [
                    'label' => 'Created By',
                    'comment' => 'Sets who submitted the ticket',
                    'tab' => 'SimpleTicket',
                    'type' => 'text',
                    'span' => 'auto',
                    'default' => 'Web User'
                ]
            ]);
        });
    }

I know this was an old thread, but I still found it useful. Hopefully this helps you guys solve your problem as well.

I have some update to this if someone is still interested. I wouldn't accept that the form was being extended only on update, and not on create. The issue here is that when you are creating a new item, it doesn't have an id yet. So the subgroup won't have a user_group_id. Hence the quickfix to not extend the form unless it's an update. Here's my work-around to that:

UserGroup::extend(function($model){
    $model->hasOne['subgroup'] = ['Codebugs\Ldap\Models\Subgroup'];

    $model->bindEvent('model.afterDelete', function() use ($model) {
        $sg = Subgroup::where('user_group_id', $model->id);
        if($sg) $sg->delete();
    });

    $model->bindEvent('model.afterCreate', function() use ($model) {
        $id = $model->id;
        $model->subgroup->user_group_id = $id; // Manually set the parent id to the subgroup
        $model->subgroup->save();
    });
});

hey i want to create a model for save the form but i dont know where to create the model please help me out