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The Build Object

The build object contains a number of helpers and sources of information relevant to the current build of the GraphQL API. If you're in watch mode then every time a new schema is generated a new build object will be used.

The following properties/methods are available on the initial build object (more may be added by plugins via the build hook):

registerObjectType(typeName, scope, specGenerator, origin)​

The bread-and-butter of Graphile Engine, this method is how we register hooked GraphQL objects:

build.registerObjectType(
  "MyType",
  { isMyType: true },
  () => {
    return {
      fields: {
        meaningOfLife: {
          type: graphql.GraphQLInt,
          plan() {
            return constant(42);
          },
        },
      },
    };
  },
  "MyType from MyPlugin",
);
  • type is a GraphQL object type, such as GraphQLEnumType or GraphQLInputObjectType
  • spec is a valid specification that will be passed through the relevant hooks before ultimately being passed to the constructor of the aforementioned type and returning an instance of that type
  • scope is where you can add scope information that will be available through the scope property in the context object passed to hooks (see Context below)

getTypeByName(typeName)​

The counterpart to register*Type, this is how we retrieve or build the GraphQL types that we registered previously.

const MyType = build.getTypeByName("MyType");

extend(input, extensions, origin)​

Returns the input object with extensions merged in without overwriting. If any clashes occur an error will be throw. It is advisable to use this instead of Object.assign or {...input, ...extensions} because it will warn you if you're accidentally overwriting something. The origin helps users to deal with clashes by determining what this call related to.

graphql​

Equivalent to require('graphql'), by using this property you don't have to import graphql and you're less likely to get version conflicts which are hard to diagnose and resolve. Use of this property over importing graphql yourself is highly recommended.