Enum MetaType

pub enum MetaType<'a, S = DefaultScalarValue> {
    // some variants omitted
}

Generic type metadata

Implementations

impl<'a, S> MetaType<'a, S>

pub fn name(&self) -> Option<&str>

Access the name of the type, if applicable

Lists, non-null wrappers, and placeholders don’t have names.

pub fn description(&self) -> Option<&str>

Access the description of the type, if applicable

Lists, nullable wrappers, and placeholders don’t have names.

pub fn specified_by_url(&self) -> Option<&str>

Accesses the specification URL, if applicable.

Only custom GraphQL scalars can have a specification URL.

pub fn type_kind(&self) -> TypeKind

Construct a TypeKind for a given type

Panics

Panics if the type represents a placeholder or nullable type.

pub fn field_by_name(&self, name: &str) -> Option<&Field<'_, S>>

Access a field’s meta data given its name

Only objects and interfaces have fields. This method always returns None for other types.

pub fn input_field_by_name(&self, name: &str) -> Option<&Argument<'_, S>>

Access an input field’s meta data given its name

Only input objects have input fields. This method always returns None for other types.

pub fn as_type(&self) -> Type<'a>

Construct a Type literal instance based on the metadata

pub fn input_value_parse_fn(&self) -> Option<InputValueParseFn<S>>

Access the input value parse function, if applicable

An input value parse function is a function that takes an InputValue instance and returns true if it can be parsed as the provided type.

Only scalars, enums, and input objects have parse functions.

pub fn is_composite(&self) -> bool

Returns true if the type is a composite type

Objects, interfaces, and unions are composite.

pub fn is_leaf(&self) -> bool

Returns true if the type can occur in leaf positions in queries

Only enums and scalars are leaf types.

pub fn is_abstract(&self) -> bool

Returns true if the type is abstract

Only interfaces and unions are abstract types.

pub fn is_input(&self) -> bool

Returns true if the type can be used in input positions, e.g. arguments or variables

Only scalars, enums, and input objects are input types.

pub fn is_builtin(&self) -> bool

Returns true if the type is built-in to GraphQL.

Trait Implementations

impl<'a, S: Debug> Debug for MetaType<'a, S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.