Struct ExtensionsJson 

pub struct ExtensionsJson(/* private fields */);

A JSON-object map of protocol extension data attached to a payment message.

ExtensionsJson is the wire representation of optional extension fields in PaymentPayload and PaymentRequired. Each extension is keyed by the string constant exposed by ExtensionKey::EXTENSION_KEY and stored as a JSON value, so heterogeneous extension types can coexist in the same map.

Serialization

Serializes to and from a JSON object (e.g. { "eip2612GasSponsoring": { … } }).

Implementations

impl ExtensionsJson

pub fn new() -> Self

Creates an empty ExtensionsJson map.

Equivalent to ExtensionsJson::default().

pub fn is_empty(&self) -> bool

Returns true if the map contains no extension entries.

pub fn insert<T>(&mut self, value: T) -> Result<Option<Value>>

where T: ExtensionKey + Serialize,

Inserts or replaces an extension entry, keyed by T::EXTENSION_KEY.

value is serialized to a serde_json::Value before insertion. If a value was previously stored under the same key, it is returned as Some(old_value).

Errors

Returns a serde_json::Error if value cannot be serialized to JSON.

pub fn get<T>(&self) -> Option<T>

where T: ExtensionKey + DeserializeOwned,

Retrieves and deserializes an extension value by its type.

The lookup key is taken from T::EXTENSION_KEY (see ExtensionKey). Returns None if the key is absent or if deserialization fails.

Type Parameters

• T – Must implement both ExtensionKey (to provide the key) and serde::de::DeserializeOwned (to decode the stored JSON value).

Trait Implementations

impl AsRef<Map<String, Value>> for ExtensionsJson

fn as_ref(&self) -> &Map<String, Value>

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for ExtensionsJson

fn clone(&self) -> ExtensionsJson

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExtensionsJson

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

Formats the value using the given formatter.

impl Default for ExtensionsJson

fn default() -> ExtensionsJson

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ExtensionsJson

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<ExtensionsJson> for Value

fn from(value: ExtensionsJson) -> Self

Converts to this type from the input type.

impl FromIterator<(String, Value)> for ExtensionsJson

fn from_iter<I: IntoIterator<Item = (String, Value)>>(iter: I) -> Self

Collects an iterator of (key, value) pairs into an ExtensionsJson.

Values must already be serde_json::Values. To build from serializable types, serialize each value with serde_json::to_value before collecting, handling any errors at the call site.

impl Serialize for ExtensionsJson

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<Value> for ExtensionsJson

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: Value) -> Result<Self, Self::Error>

Performs the conversion.