Struct Attribute 

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

Defines one durable, typed value stored with a Flow.

Declare Attributes on the Flow, add them to crate::PersistenceSchema, and reuse the same definition from Step and RPC code. Values use Serde serialization. get distinguishes a missing value with None; get_required converts absence into HandlerError.

Examples

use dex_sdk::{Attribute, AttributeIndex};

let status = Attribute::<String>::new("status")
    .indexed(AttributeIndex::keyword());

Implementations

impl<T> Attribute<T>

pub fn new(name: impl Into<String>) -> Self

Defines an unindexed Attribute with stable name.

pub fn indexed(self, index: AttributeIndex) -> Self

Enables Flow-search indexing with the selected index type.

pub fn sync_to_attribute_store(self) -> Self

Enables asynchronous latest-state projection to the Flow’s selected Attribute Store.

The Flow must select a server-configured store with FlowConfig::attribute_store_names. Deletions project SQL NULL, and projection failures never roll back the Flow Attribute write.

pub fn get(&self, context: &Context) -> HandlerResult<Option<T>>

where T: Value,

Reads the current value from a Step or RPC invocation.

Returns Ok(None) when no value is stored.

Errors

Returns HandlerError when the payload cannot be decoded.

pub fn get_required(&self, context: &Context) -> HandlerResult<T>

where T: Value,

Reads the current value and treats absence as an error.

Errors

Returns HandlerError when the Attribute is missing or cannot be decoded.

pub fn set(&self, context: &mut Context, value: T) -> HandlerResult<()>

where T: Value,

Stages value for durable persistence in the current invocation.

Errors

Returns HandlerError when the value cannot be encoded or indexed.

pub fn delete(&self, context: &mut Context) -> HandlerResult<()>

Stages deletion of the current value.

Deleting a missing Attribute is valid.

pub fn lock(&self) -> AttributeLock

Creates a lock request for Step options or an RPC definition.

Trait Implementations

impl<T> Clone for Attribute<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.