AWS AppSync - Directive "aws_subscribe" may not be used on FIELD_DEFINITION - amazon-web-services

Question

I'm trying to get to grips with AWS AppSync. I'm quite new to GraphQL. I've got the following GraphQL:
type Mutation {
deleteParcel(geoHash: String!, type_id: String!): Parcel
addParcel(input: ParcelInput!): Parcel
batchAddParcels(parcels: [ParcelInput]): [Parcel]
}
type Parcel {
geoHash: String!
type_id: String!
}
type ParcelConnection {
items: [Parcel]
}
input ParcelInput {
geoHash: String!
type_id: String!
}
input ParcelsInput {
parcels: [ParcelInput]
}
type Query {
getNearbyParcels(geoHash: String!): ParcelConnection
}
type Subscription {
onAddParcel(geoHash: String, type_id: String): Parcel
#aws_subscribe(mutations: ["addParcel"])
onBatchAddParcels(geoHash: String): Parcel
#aws_subscribe(mutations: ["batchAddParcels"])
onDeleteParcel(geoHash: String, type_id: String): Parcel
#aws_subscribe(mutations: ["deleteParcel"])
}
schema {
query: Query
mutation: Mutation
subscription: Subscription
}
All seems to be setup fine on AWS console. I get the schema.json and then run command:
aws-appsync-codegen generate AWSGraphQL.graphql --schema schema.json --output AppsyncAPI.swift
and get the response:
../SnatchHQ/snatch_appsync/AppSync/AWSGraphQL.graphql: Directive "aws_subscribe" may not be used on FIELD_DEFINITION.
.../SnatchHQ/snatch_appsync/AppSync/AWSGraphQL.graphql: Directive "aws_subscribe" may not be used on FIELD_DEFINITION.
.../SnatchHQ/snatch_appsync/AppSync/AWSGraphQL.graphql: Directive "aws_subscribe" may not be used on FIELD_DEFINITION.
error: Validation of GraphQL query document failed
Can anyone help?

Answer 1

If the file AWSGraphQL.graphql is your API GraphQL schema, then that explains the problem. What you need to do is define a *.graphql file that defines your query, mutation, and subscription operations based on your GraphQL API. For example, the following query definitions would match your schema
mutation AddParcel($geoHash: String!, $type_id: String!) {
addParcel(input: {
geoHash: $geoHash
type_id: $typeId
}) {
...Parcel
}
}
query GetNearbyParcels($geoHash: String!) {
getNearbyParcels(
geoHash: $geoHash
) {
...ParcelConnection
}
}
subscription OnAddParcel {
onAddParcel {
...Parcel
}
}
fragment Parcel on Parcel {
geoHash
type_id
}
fragment ParcelConnection on Parcel Connection {
items {
...Parcel
}
}
Assuming you named it something like parcels.graphql, you can then call the following to generate a Swift implementation of the AddParcel mutation, the GetNearbyParcels query, and the OnAddParcel subscription
aws-appsync-codegen generate parcels.graphql \
--schema schema.json \
--output AppSyncParcelsAPI.swift