Use a GQLObject as arg for a mutation? - node.js

Question

I have following mutation on serverside (nodeJS) (RequiredDataType is imported):
mutationA: {
type: MutationResponseType,
args: {
id: {
type: new GraphQLNonNull(GraphQLString)
},
name: {
type: new GraphQLNonNull(GraphQLString)
},
requiredData: {
type: new GraphQLNonNull(new GraphQLList(RequiredDataType))
}
},
async resolve(parentValue, {
id,
name,
requiredData
}, req) {
// Some Magic Code
}
},
The RequiredDataType is coded as follow (All GraphQL things are imported :)):
const RequiredDataType = new GraphQLObjectType({
name: 'RequiredDataType',
fields: {
name: {
type: GraphQLString
},
value: {
type: GraphQLString
},
required: {
type: GraphQLBoolean
}
}
});
module.exports = RequiredDataType;
When I use this code I get the following error: "module initialization error: Error"
If I change the RequiredDataType in the mutation to GraphQLString it works without any error but I can't use the object which I need :)
At the end I will send and process following data structure:
{
"name": "Hallo"
"id": "a54de3d0-a0a6-11e7-bf70-7b64ae72d2b6",
"requiredData": [
{
"name": "givenName",
"value": null,
"required": true
},
{
"name": "familyName",
"value": null,
"required": false
}
]
}
On the client (reactJS with apollo-client) I use the following gql-tag code:
export default gql`
mutation MutationA($id: String!, $name: String!, $requiredData: [RequiredDataType]!){
mutationA(id: $id, name: $name, requiredData: $requiredData) {
id,
somethingElse
}
}
`;
But in the first place it crashes on the mutation declaration on the server. So is it not possible to use and GQLObject as an argument at an mutation or where is my error in the code?
Thank you for your help!
Best,
Fabian

Answer 1

Unfortunately, a type cannot be used in place of an input, and an input cannot be used in place of a type. This is by design. From the official specification:
Fields can define arguments that the client passes up with the query,
to configure their behavior. These inputs can be Strings or Enums, but
they sometimes need to be more complex than this.
The Object type defined above is inappropriate for re‐use here,
because Objects can contain fields that express circular references or
references to interfaces and unions, neither of which is appropriate
for use as an input argument. For this reason, input objects have a
separate type in the system.
You can check this answer for more details as to the why
You'll need to define RequiredDataType as a GraphQLInputObjectType, not a GraphQLObjectType, to get your mutation working. If you need it as a GraphQLObjectType too, you'll need to declare them as two separate types -- something like RequiredDataType and RequiredDataInput.