Enum MaybeUndefined

pub enum MaybeUndefined<T> {
    Undefined,
    Null,
    Value(T),
}

Similar to Option, but it has three states, undefined, null and x.

Example

use poem::{test::TestClient, IntoEndpoint};
use poem_openapi::{payload::Json, types::MaybeUndefined, Object, OpenApi, OpenApiService};
use tokio::sync::Mutex;
use serde_json::json;

#[derive(Object, Clone, Default)]
struct Resource {
    attr1: Option<i32>,
    attr2: Option<String>,
}

#[derive(Object)]
struct UpdateResourceRequest {
    attr1: MaybeUndefined<i32>,
    attr2: MaybeUndefined<String>,
}

struct Api {
    resource: Mutex<Resource>,
}

#[OpenApi]
impl Api {
    #[oai(path = "/get", method = "get")]
    async fn get_resource(&self) -> Json<Resource> {
        Json(self.resource.lock().await.clone())
    }

    #[oai(path = "/put", method = "put")]
    async fn update_resource(&self, req: Json<UpdateResourceRequest>) {
        let mut resource = self.resource.lock().await;

        match req.0.attr1 {
            MaybeUndefined::Null => resource.attr1 = None,
            MaybeUndefined::Value(value) => resource.attr1 = Some(value),
            MaybeUndefined::Undefined => {}
        }

        match req.0.attr2 {
            MaybeUndefined::Null => resource.attr2 = None,
            MaybeUndefined::Value(value) => resource.attr2 = Some(value),
            MaybeUndefined::Undefined => {}
        }
    }
}

let api_service = OpenApiService::new(
    Api {
        resource: Default::default(),
    },
    "Test",
    "1.0",
);

let cli = TestClient::new(api_service.into_endpoint());

cli.get("/get").send().await.assert_json(json!({"attr1": null, "attr2": null}));

cli.put("/put").body_json(&json!({"attr1": 100i32})).send().await.assert_status_is_ok();
cli.get("/get").send().await.assert_json(json!({"attr1": 100i32, "attr2": null}));

cli.put("/put").body_json(&json!({"attr1": null, "attr2": "abc"})).send().await.assert_status_is_ok();
cli.get("/get").send().await.assert_json(json!({"attr1": null, "attr2": "abc"}));

Variants

Undefined

Undefined

Null

Null

Value(T)

Value

Implementations

impl<T> MaybeUndefined<T>

pub fn from_opt_undefined(value: Option<T>) -> Self

Create a MaybeUndefined<T> from Option<T>, returns MaybeUndefined::Undefined if this value is none.

pub fn from_opt_null(value: Option<T>) -> Self

Create a MaybeUndefined<T> from Option<T>, returns MaybeUndefined::Null if this value is none.

pub const fn is_undefined(&self) -> bool

Returns true if the MaybeUndefined<T> is undefined.

pub const fn is_null(&self) -> bool

Returns true if the MaybeUndefined<T> is null.

pub const fn is_value(&self) -> bool

Returns true if the MaybeUndefined<T> contains value.

pub const fn value(&self) -> Option<&T>

Returns None if the the MaybeUndefined<T> is undefined or null, otherwise returns Some(&T).

pub fn value_mut(&mut self) -> Option<&mut T>

Returns None if the the MaybeUndefined<T> is undefined or null, otherwise returns Some(&mut T).

pub fn take(self) -> Option<T>

Converts the MaybeUndefined<T> to Option<T>.

pub const fn as_ref(&self) -> MaybeUndefined<&T>

Converts from &MaybeUndefined<T> to MaybeUndefined<&T>.

pub const fn as_opt_ref(&self) -> Option<Option<&T>>

Converts the MaybeUndefined<T> to Option<Option<T>>.

pub fn as_opt_deref<U>(&self) -> Option<Option<&U>>

where U: ?Sized, T: Deref<Target = U>,

Converts the MaybeUndefined<T> to Option<Option<&U>>.

pub fn contains_value<U>(&self, x: &U) -> bool

where U: PartialEq<T>,

Returns true if the MaybeUndefined<T> contains the given value.

pub fn contains<U>(&self, x: &Option<U>) -> bool

where U: PartialEq<T>,

Returns true if the MaybeUndefined<T> contains the given nullable value.

pub fn map<U, F: FnOnce(Option<T>) -> Option<U>>( self, f: F, ) -> MaybeUndefined<U>

Maps a MaybeUndefined<T> to MaybeUndefined<U> by applying a function to the contained nullable value

pub fn map_value<U, F: FnOnce(T) -> U>(self, f: F) -> MaybeUndefined<U>

Maps a MaybeUndefined<T> to MaybeUndefined<U> by applying a function to the contained value

pub fn update_to(self, value: &mut Option<T>)

Update value if the MaybeUndefined<T> is not undefined.

Example

use poem_openapi::types::MaybeUndefined;

let mut value = None;

MaybeUndefined::Value(10i32).update_to(&mut value);
assert_eq!(value, Some(10));

MaybeUndefined::Undefined.update_to(&mut value);
assert_eq!(value, Some(10));

MaybeUndefined::Null.update_to(&mut value);
assert_eq!(value, None);

impl<T: Deref> MaybeUndefined<T>

pub fn as_deref(&self) -> MaybeUndefined<&T::Target>

Converts from MaybeUndefined<T> (or &MaybeUndefined<T>) to MaybeUndefined<&T::Target>.

impl<T, E> MaybeUndefined<Result<T, E>>

pub fn transpose(self) -> Result<MaybeUndefined<T>, E>

Transposes a MaybeUndefined of a Result into a Result of a MaybeUndefined.

MaybeUndefined::Undefined will be mapped to Ok(MaybeUndefined::Undefined). MaybeUndefined::Null will be mapped to Ok(MaybeUndefined::Null). MaybeUndefined::Value(Ok(_)) and MaybeUndefined::Value(Err(_)) will be mapped to Ok(MaybeUndefined::Value(_)) and Err(_).

Trait Implementations

impl<T: Clone> Clone for MaybeUndefined<T>

fn clone(&self) -> MaybeUndefined<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for MaybeUndefined<T>

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

Formats the value using the given formatter.

impl<T> Default for MaybeUndefined<T>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for MaybeUndefined<T>

where T: Deserialize<'de>,

fn deserialize<D>(deserializer: D) -> Result<MaybeUndefined<T>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> From<MaybeUndefined<T>> for Option<Option<T>>

fn from(maybe_undefined: MaybeUndefined<T>) -> Self

Converts to this type from the input type.

impl<T> From<Option<Option<T>>> for MaybeUndefined<T>

fn from(value: Option<Option<T>>) -> Self

Converts to this type from the input type.

impl<T> From<T> for MaybeUndefined<T>

fn from(value: T) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for MaybeUndefined<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T> IntoIterator for MaybeUndefined<T>

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T: Ord> Ord for MaybeUndefined<T>

fn cmp(&self, other: &MaybeUndefined<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: ParseFromJSON> ParseFromJSON for MaybeUndefined<T>

fn parse_from_json(value: Option<Value>) -> ParseResult<Self>

Parse from serde_json::Value.

fn parse_from_json_string(s: &str) -> ParseResult<Self>

Parse from JSON string.

impl<T: ParseFromMultipartField> ParseFromMultipartField for MaybeUndefined<T>

async fn parse_from_multipart(value: Option<PoemField>) -> ParseResult<Self>

Parse from multipart field.

fn parse_from_repeated_field( self, _field: PoemField, ) -> impl Future<Output = ParseResult<Self>> + Send

Parse from repeated multipart field.

impl<T: ParseFromParameter> ParseFromParameter for MaybeUndefined<T>

fn parse_from_parameter(_value: &str) -> ParseResult<Self>

Parse from parameter.

fn parse_from_parameters<I: IntoIterator<Item = A>, A: AsRef<str>>( iter: I, ) -> ParseResult<Self>

Parse from multiple parameters.

impl<T: PartialEq> PartialEq for MaybeUndefined<T>

fn eq(&self, other: &MaybeUndefined<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for MaybeUndefined<T>

fn partial_cmp(&self, other: &MaybeUndefined<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Serialize> Serialize for MaybeUndefined<T>

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl<T: ToHeader> ToHeader for MaybeUndefined<T>

fn to_header(&self) -> Option<HeaderValue>

Convert this value to HeaderValue.

impl<T: ToJSON> ToJSON for MaybeUndefined<T>

fn to_json(&self) -> Option<Value>

Convert this value to Value.

fn to_json_string(&self) -> String

Convert this value to JSON string.

impl<T: Type> Type for MaybeUndefined<T>

const IS_REQUIRED: bool = false

If it is true, it means that this type is required.

type RawValueType = <T as Type>::RawValueType

The raw type used for validator.

type RawElementValueType = <T as Type>::RawElementValueType

The raw element type used for validator.

fn name() -> Cow<'static, str>

Returns the name of this type

fn schema_ref() -> MetaSchemaRef

Get schema reference of this type.

fn register(registry: &mut Registry)

Register this type to types registry.

fn as_raw_value(&self) -> Option<&Self::RawValueType>

Returns a reference to the raw value.

fn raw_element_iter<'a>( &'a self, ) -> Box<dyn Iterator<Item = &'a Self::RawElementValueType> + 'a>

Returns an iterator for traversing the elements.

fn is_none(&self) -> bool

Returns true if this value is none.

fn is_empty(&self) -> bool

Returns true if this value is empty.

impl<T: Copy> Copy for MaybeUndefined<T>

impl<T: Eq> Eq for MaybeUndefined<T>

impl<T> StructuralPartialEq for MaybeUndefined<T>