Struct MqttContext 

#[non_exhaustive]
pub struct MqttContext { /* private fields */ }

The per-delivery context of this broker.

Read a field with a key rather than by field access: ctx.context(DeliveryTopic) in a handler body, cx.context(DeliveryTopic) in a publish transform on the reply or the retry position.

Examples

use ruststream_rumqttc::prelude::*;
use serde::Deserialize;

#[derive(Deserialize)]
struct Telemetry {
    temperature: f64,
}

#[subscriber(MqttFilter::new("devices/+/telemetry"))]
async fn record(telemetry: &Telemetry, ctx: &mut Context<'_, MqttContext>) -> HandlerOutcome {
    let device = ctx.context(DeliveryTopic).split('/').nth(1).unwrap_or_default();
    tracing::info!(device, telemetry.temperature, "reading recorded");
    HandlerOutcome::ack()
}

#[ruststream::app]
fn app() -> impl App {
    RustStream::new(AppInfo::new("telemetry", "0.1.0")).with_broker(
        MqttBroker::new("mqtt://localhost:1883", "telemetry-svc"),
        |b| {
            b.include(record)
                .out_retry(Publish::default())
                .to("devices/retry/telemetry");
        },
    )
}

Implementations

impl MqttContext

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

Builds the context of a delivery that arrived on topic.

pub fn topic(&self) -> &str

The concrete topic this delivery was published to, never the filter that matched it.

Trait Implementations

impl BuildContext<MqttMessage> for MqttContext

fn build(msg: &MqttMessage) -> Self

Builds the context value by reading fields out of msg.

impl Clone for MqttContext

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MqttContext

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

Formats the value using the given formatter.

impl Eq for MqttContext

impl Field<MqttContext> for DeliveryTopic

type Value<'a> = &'a str

The value read through this key, borrowed from the source for 'a.

fn get(self, src: &MqttContext) -> &str

Reads this key’s field out of src.

impl PartialEq for MqttContext

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for MqttContext