Struct cw_storage_plus::Item

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

Item stores one typed item at the given key. This is an analog of Singleton. It functions the same way as Path does but doesn’t use a Vec and thus has a const fn constructor.

Implementations

impl<T> Item<T>

pub const fn new(storage_key: &'static str) -> Self

Creates a new Item with the given storage key. This is a const fn only suitable when you have a static string slice.

pub fn new_dyn(storage_key: impl Into<Namespace>) -> Self

Creates a new Item with the given storage key. Use this if you might need to handle a dynamic string. Otherwise, you might prefer Item::new.

impl<T> Item<T>

where T: Serialize + DeserializeOwned,

pub fn as_slice(&self) -> &[u8]

pub fn save(&self, store: &mut dyn Storage, data: &T) -> StdResult<()>

save will serialize the model and store, returns an error on serialization issues

pub fn remove(&self, store: &mut dyn Storage)

pub fn load(&self, store: &dyn Storage) -> StdResult<T>

load will return an error if no data is set at the given key, or on parse error

pub fn may_load(&self, store: &dyn Storage) -> StdResult<Option<T>>

may_load will parse the data stored at the key if present, returns Ok(None) if no data there. returns an error on issues parsing

pub fn exists(&self, store: &dyn Storage) -> bool

Returns true if data is stored at the key, false otherwise.

pub fn update<A, E>(&self, store: &mut dyn Storage, action: A) -> Result<T, E>

where A: FnOnce(T) -> Result<T, E>, E: From<StdError>,

Loads the data, perform the specified action, and store the result in the database. This is shorthand for some common sequences, which may be useful.

It assumes, that data was initialized before, and if it doesn’t exist, Err(StdError::NotFound) is returned.

pub fn query<Q: CustomQuery>( &self, querier: &QuerierWrapper<'_, Q>, remote_contract: Addr ) -> StdResult<T>

If you import the proper Item from the remote contract, this will let you read the data from a remote contract in a type-safe way using WasmQuery::RawQuery.

Note that we expect an Item to be set, and error if there is no data there