Module serde_with::rust::string_empty_as_none
source · [−]Expand description
De/Serialize a Option<String>
type while transforming the empty string to None
Convert an Option<T>
from/to string using FromStr
and AsRef<str>
implementations.
An empty string is deserialized as None
and a None
vice versa.
Converting to serde_as
The same functionality can be more clearly expressed via NoneAsEmptyString
and using the serde_as
macro.
#[serde_as]
#[derive(Deserialize)]
struct A {
#[serde_as(as = "NoneAsEmptyString")]
value: Option<String>,
}
Examples
#[derive(Deserialize, Serialize)]
struct A {
#[serde(with = "string_empty_as_none")]
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());
Functions
Deserialize an Option<T>
from a string using FromStr
Serialize a string from Option<T>
using AsRef<str>
or using the empty string if None
.