Laravel conditional relationship - hasOne specified by model's type-CodePudding

I have a model Chapter which have field type than can be (article, video, quiz). To solve my problem I have to create a new model Quiz which will have relationship oneToOne with Chapter model whether type of Chapter == "quiz".

I've tried something like this and it works when type == "quiz" only. I guess I'll have to return other relations for other types for it to work, but I don't have nothing to return so I wanted to leave it empty for other types.

public function quizQuestions(){
        if($this->chapter_type == "QUIZ"){
            return $this->hasMany(QuizQuestion::class);
        }
    }

The point is, I want to somehow return empty relation for other types. I'm building an app in Laravel Nova and I wanted to hide Quiz table if a chapter is not type of "quiz" but it can't be done this way.

NovaDependencyContainer::make([
   HasMany::make('QuizQuestions'),
])->dependsOn('chapter_type' , \App\Models\Chapter::QUIZ),

I might have missed something in documentation or I just don't understand something so thanks in advance for you help and advices!

CodePudding user response：

Try returning null otherwise:

public function quizQuestions(){
        if($this->chapter_type == "QUIZ"){
            return $this->hasMany(QuizQuestion::class);
        }
       return $this->hasMany(QuizQuestion::class)->where('id', -1);
    }

CodePudding user response：

I advise you to re-think your Model, but not too many edits.

I have done things like you want in this manner:

return $this->hasMany('App\Models\Main\QuizQuestion','id','id')->where('chapter_type', '=', 1);

then ->where('chapter_type', '=', 2);

Works like a charm!!