Graphqlbundle: Question: Interfaces and their implementations properties

Created on 4 May 2018 · 5Comments · Source: overblog/GraphQLBundle

| Q | A
| ---------------- | -----
| Bug report? | no
| Feature request? | no
| BC Break report? | no
| RFC? | no

overblog/graphql-bundle                         v0.10.3           
overblog/graphql-php-generator                  v0.6.0            
webonyx/graphql-php                             v0.11.6

I have an issue where Executor complains that a non-nullable field is null when the object to return is from an implementation of an Interface and the property is from another implementation.

  - Cannot return null for non-nullable field File.versions.
     * vendor/webonyx/graphql-php/src/Executor/Executor.php:923

The object to return is from the class Folder, a sibling of File.

My (simplified) definitions are as follow:

Path:
    type: interface
    config:
        fields:
            id:
                type: 'ID!'
            name:
                type: 'String!'

File:
    type: object
    config:
        fields:
            id:
                type: 'ID!'
            name:
                type: 'String!'
            versions:
                type: '[Version]!'
        interfaces:
            - Path

Folder:
    type: object
    config:
        fields:
            id:
                type: 'ID!'
            name:
                type: 'String!'
        interfaces:
            - Path

The query is:

   tree {
        items {
            id
            name
            ... on File {
                versions{
                    fullName
                    downloadLink
                }
            }
        }
    }

The php classes Folder.php and File.php extend the class Path.php. Only File.php has a property $versions. The value version is only requested for the type File. But the Executor refuses to return a Folder object.

I "fixed" the issue by moving $versions to Path.php, but I don't understand what I'm doing wrong. If a property is defined for a type, why should it also be defined for all "siblings" of that type?

question

Source

Alsciende

😄1

Most helpful comment

Hi @Alsciende , maybe this POC can help you : https://github.com/Samffy/graphql-poc
It use a simple model, but implement interface.

@mcg-web, do not hesitate to criticize this work if you notice some issues.

Samffy on 10 May 2018

👍3

All 5 comments

Hi does your resolver correctly returns version, also what about resolveType config on Path type?
(Sorry for late reply I was a way busy last few days.)