Recipes

Project relation with custom resolver logic#

Nexus Prisma generates default GraphQL resolvers for your model relation fields. However you may want to run custom logic in the resolver. This is easy to do. The following show a few ways.

1. Wrap Style You can access the default resolver within your own custom resolver.

   objectType({
     name: User.$name,
     definition(t) {
       t.field(User.id)
       t.field({
         ...User.posts,
         async resolve(...args) {
           // Your custom before-logic here
           const result = await User.posts.resolve(...args)
           // Your custom after-logic here
           return result
         },
       })
     },
   })

2. Replace Style You can simply opt out of using the default resolver completely:

   objectType({
     name: User.$name,
     definition(t) {
       t.field(User.id)
       t.field({
         ...User.posts,
         async resolve(...args) {
           // Your custom logic here
         },
       })
     },
   })

Supply custom scalars to your GraphQL schema#

The following is a brief example how you could add your own custom GraphQL custom scalars to satisfy Nexus Prisma. Note that most of the time using the defaults exported by nexus-prisma/scalars will probably be good enough for you.

import { GraphQLScalarType } from 'graphql'
import { JSONObjectResolver, DateTimeResolver } from 'graphql-scalars'
import { asNexusMethod, makeSchema } from 'nexus'

const jsonScalar = new GraphQLScalarType({
  ...JSONObjectResolver,
  // Override the default 'JsonObject' name with one that matches what Nexus Prisma expects.
  name: 'Json',
})

const dateTimeScalar = new GraphQLScalarType(DateTimeResolver)

makeSchema({
  types: [asNexusMethod(jsonScalar, 'json'), asNexusMethod(dateTimeScalar, 'dateTime')],
})