Extensions

GraphQL does not deal with a specific strategy for implementing directives, it is up to each GraphQL server implementation to expose an API for implementing new directives. Documentation on directives with Apollo

You can assign directives with parameters via all GraphQL element decorators (@ObjectType, @InputType, @InterfaceType @Arg, @Field, ...). However, if you want to assign directives commonly for all types, or all fields, it is more convenient to use @Directive.

Use of @Directive

This is done simply by passing a name and arguments (optional) to the @Directive decorator.

If you want to put multiple directives on an element, you'll need to use the decorator multiple times

@ObjectType()
@InputType()
@Directive( upper)
@Directive("test", { class: "User" })
class User {
  @ObjectField()
  @InputField()
  @Directive( upper)
  username: string;
}

Use of directives separately

This is done via the parameters of the element decorators:

ObjectType({
  guidelines: [
    { name: "upper" }
  ]
})
InputType({
  guidelines: [
    {
      name: "upper",
      args: { class: "input-User" }
    }
  ]
})
class User {
  ObjectField({
    guidelines: [
      { name: "upper-object" }
    ]
  })
  InputField({
    guidelines: [
      { name: "upper-input" }
    ]
  })
  username: string;
}