Struct NoneAsEmptyString 

pub struct NoneAsEmptyString;

De/Serialize a Option<String> type while transforming the empty string to None

Convert an Option<T> from/to string using FromStr and Display implementations. An empty string is deserialized as None and a None vice versa.

Examples

#[serde_as]
#[derive(Deserialize, Serialize)]
struct A {
    #[serde_as(as = "NoneAsEmptyString")]
    tags: Option<String>,
}

let v: A = serde_json::from_value(json!({ "tags": "" })).unwrap();
assert_eq!(None, v.tags);

let v: A = serde_json::from_value(json!({ "tags": "Hi" })).unwrap();
assert_eq!(Some("Hi".to_string()), v.tags);

let x = A {
    tags: Some("This is text".to_string()),
};
assert_eq!(json!({ "tags": "This is text" }), serde_json::to_value(x).unwrap());

let x = A {
    tags: None,
};
assert_eq!(json!({ "tags": "" }), serde_json::to_value(x).unwrap());

Trait Implementations

impl<'de, Str> DeserializeAs<'de, Option<Str>> for NoneAsEmptyString

where Str: FromStr, Str::Err: Display,

fn deserialize_as<D>(deserializer: D) -> Result<Option<Str>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> SerializeAs<Option<T>> for NoneAsEmptyString

where T: Display,

fn serialize_as<S>(source: &Option<T>, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 0 bytes