validate and handle error to pass meaningful status back to client

Question

I am using graphene-django instead of rest api(rest framework). I am working on user registration. In the rest framework, validation was done in serializers part but when using graphene how do i validate and handle error for passing meaningful status to client?

Here is the registration code

class Register(graphene.Mutation):
    class Arguments:
        email = graphene.String(required=True)
        password = graphene.String(required=True)
        password_repeat = graphene.String(required=True)

    user = graphene.Field(UserQuery)
    success = graphene.Boolean()
    errors = graphene.List(graphene.String)

    @staticmethod
    def mutate(self, info, email, password, password_repeat):
        if password == password_repeat:
            try:
                user = User.objects.create(email=email)
                user.set_password(password)
                user.is_active = False
                user.full_clean()
                user.save()
                return Register(success=True, user=user)
            except ValidationError as e:
                import pdb
                pdb.set_trace()
                return Register(success=False, errors=[e])
        return Register(success=False, errors=['password', 'password is not matching'])

one example can be validation for if user with email already exists

donnyyy · Accepted Answer · 2019-07-27T23:23:55.083

2

The easiest way looks like:

    @staticmethod
    def mutate(root, info, email, password, password_repeat):
        errors = []
        if password == password_repeat:
            errors.append('password_is_not_matching')

        if User.objects.filter(email=email).exists():
            errors.append('email_is_already_registred')

        if len(errors) == 0:
            try:
                user = User.objects.create(email=email)
                user.set_password(password)
                user.is_active = False
                user.full_clean()
                user.save()
                return Register(success=True, user=user)
            except ValidationError as e:
                import pdb
                pdb.set_trace()
                return Register(success=False, errors=[e])
        return Register(success=False, errors=errors)

But problems may appear if you make a lot of such checks - code becomes more complicated and it's harder to figure out what actually mutations do.

For more information read this article.

edited Jul 27 '19 at 23:23

answered Jul 25 '19 at 16:17

donnyyy

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3
11

"But problems may appear if you make a lot of such checks -". what can be the recommended solution for this? I did not find much resources on validation relating to graphene so the best possible solution might helps lots of other developer too, i think. – Serenity Jul 26 '19 at 00:20
That is a long talk, so here is a link to the article about that https://medium.com/@don.skoy.333/year-of-adventures-with-graphene-533ef9b8c0b0 – donnyyy Jul 27 '19 at 23:23
Million thanks This will sure help everyone who encountered such issue. – Serenity Jul 29 '19 at 04:45

validate and handle error to pass meaningful status back to client

1 Answers1