nullability v0.1

Experimental nullability directives

StatusRelease
Version0.1

This specification provides a list of directives to help dealing with nullability. For more information, see the nullability working group GitHub repository.

1@semanticNonNull

"""
Indicates that a field is only null if there is a matching error in the `errors` array.
In all other cases, the field is non-null.

Tools doing code generation may use this information to generate the field as non-null.

This directive can be applied on field definitions:

```graphql
type User {
    email: String @semanticNonNull
}
```

It can also be applied on object type extensions for use in client applications that do
not own the base schema:

```graphql
extend type User @semanticNonNull(field: "email")
```

Control over list items is done using the `level` argument:

```graphql
type User {
    # friends is nullable but friends[0] is null only on errors
    friends: [User] @semanticNonNull(level: 1)
}
```

The `field` argument is the name of the field if `@semanticNonNull` is applied to an object definition.
If `@semanticNonNull` is applied to a field definition, `field` must be null.

The `level` argument can be used to indicate what level is semantically non null in case of lists.
`level` starts at 0 if there is no list. If `level` is null, all levels are semantically non null.
"""
directive @semanticNonNull(field: String = null, level: Int = null) repeatable on FIELD_DEFINITION | OBJECT

2@catch

"""
Indicates how clients should handle errors on a given position.

When used on the schema definition, `@catch` applies to every position that can return an error.

The `level` argument can be used to indicate where to catch in case of lists.
`level` starts at 0 if there is no list. If `level` is null, all levels catch.

See `CatchTo` for more details.
"""
directive @catch(to: CatchTo! = RESULT, level: Int = null) repeatable on FIELD | SCHEMA

3@ignoreErrors

"""
Never throw on field errors.

This is used for backward compatibility for clients where this was the default behaviour.
"""
directive @ignoreErrors on QUERY | MUTATION | SUBSCRIPTION

§Index

  1. @catch
  2. @ignoreErrors
  3. @semanticNonNull
  1. 1@semanticNonNull
  2. 2@catch
  3. 3@ignoreErrors
  4. §Index