Attribute Macro actix_handler 

#[actix_handler]

Allows writing Actix actors with impl blocks.

Motivation

Actix can be quite verbose when declaring handlers:

use actix::Actor;
use actix::Context;
use actix::Handler;
use actix::Message;

struct Example;

impl Actor for Example {
    type Context = Context<Example>;
}

#[derive(Message)]
#[rtype(result = "String")]
struct Greeting { name: String }

impl Handler<Greeting> for Example {
    type Result = String;

    fn handle(&mut self, msg: Greeting, ctx: &mut Context<Self>) -> Self::Result {
        unimplemented!()
    }
}

actix_derive_macro reads an impl block and generates a bit of this code for each method.

Usage

use actix_handler_macro::{Actor, actix_handler};
use actix::{Actor, Addr, Context, Message, System};


#[derive(Actor)]
struct Example;

type ExampleContext = Context<Example>;

#[derive(Clone, Message)]
#[rtype(result = "String")]
struct Greeting { name: String }

#[actix_handler]
impl Example {
    fn greet(&self, message: Greeting, _ctx: &ExampleContext) -> String {
        format!("Hello {}", message.name).to_string()
    }
}

fn example_usage() {
    let mut sys = System::new("actix-test-runtime");
    let addr: Addr<Example> = Example {}.start();

    sys.block_on(async move {
        let greeting = Greeting { name: "you".to_string() };
        // `Example` has its handler impl block
        let result = addr.send(greeting.clone()).await.ok().unwrap();
        assert_eq!(result, "Hello you");

        // An Addr trait is also expanded:
        let result = addr.greet(greeting.clone()).await.ok().unwrap();
        assert_eq!(result, "Hello you")
    });
}

This will expand a Handler<Greeting> impl for each method in Example.

Actor ...Addr trait

It’ll also output a trait GreetingAddr and its implementation for Addr<Example> with convenience methods:

// Example output
trait GreetingAddr {
    fn greet(self: &Self, msg: Greeting) -> actix::prelude::Request<Example, Greeting>;
}

RecipientRequest

Optionally, the trait can use a actix::Recipient and return a actix::RecipientRequest.

use actix::{Message};
use actix_handler_macro::{actix_handler, Actor};

#[derive(Actor)]
struct Example;
type ExampleContext = actix::Context<Example>;
#[derive(Message)]
#[rtype(result = "String")]
struct Greeting { name: String }

#[actix_handler(use_recipient)]
impl Example {
    fn greet(&self, message: Greeting, _ctx: &ExampleContext) -> String {
        format!("Hello {}", message.name).to_string()
    }
}

#[actix_handler(use_recipient)] will expand the GreetingAddr trait as:

// Example output
trait GreetingAddr {
    fn greet(self: &Self, msg: Greeting) -> actix::RecipientRequest<Greeting>;
}

A mock of the actor could be implemented as:

use actix::Message;
use actix_handler_macro::Actor;

#[derive(Actor)]
struct Example;

#[derive(Message)]
#[rtype(result = "String")]
struct Greeting;

#[derive(Actor)]
struct ExampleMock {
    mocker: actix::Addr<actix::actors::mocker::Mocker<Example>>,
}

impl GreetingAddr for ExampleMock {
    fn greet(self: &Self, msg: Greeting) -> actix::prelude::RecipientRequest<Greeting> {
        self.mocker.clone().recipient().send(msg)
    }
}