Struct AttributeMapInstance 

pub struct AttributeMapInstance<T> { /* private fields */ }

Selects one AttributeMap instance for Client::get_attributes.

Since 1.31.0.

Create it with AttributeMap::instance and pass a reference to it in the tuple of reads. It carries the AttributeMap definition, the instance key, and the value type T. The read returns Option<T>, which is None when the instance is not set.

It is a different type from AttributeMapLoad. An AttributeMap::load result selects an instance to load into a handler Context. Client::get_attributes does not accept it.

Creating an instance selector does not validate the key. Client::get_attributes rejects an empty key or a key that contains / with SdkError::InvalidArgument.

Examples

use dex_sdk::{AttributeMap, Client};
use std::sync::LazyLock;

static LINE_QUANTITIES: LazyLock<AttributeMap<u32>> =
    LazyLock::new(|| AttributeMap::new("line-quantities"));

fn read_line_quantity(client: &Client, order_id: &str) -> dex_sdk::SdkResult<u32> {
    let (quantity,) = client.get_attributes(order_id, (&LINE_QUANTITIES.instance("line-1"),))?;
    Ok(quantity.unwrap_or(0))
}

Implementations

impl<T> AttributeMapInstance<T>

pub fn attribute_map(&self) -> &AttributeMap<T>

Returns the AttributeMap definition this selector reads.

pub fn instance(&self) -> &str

Returns the instance key exactly as it was passed to AttributeMap::instance.

Trait Implementations

impl<T: Value> AttributeRead for AttributeMapInstance<T>

type Value = T

The decoded value type of the selected Attribute or AttributeMap instance.

impl<T> Clone for AttributeMapInstance<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.