Crate mediator

Expand description

mediator-rs

An implementation of the Mediator pattern in Rust inspired in C# MediatR.

Mediator Pattern

https://en.wikipedia.org/wiki/Mediator_pattern

Usage

[dependencies]
mediator = "0.1"

Example

use mediator::{DefaultMediator, Mediator, Request, Event, RequestHandler, EventHandler};

#[derive(Clone, Debug)]
enum Op {
 Add(f32, f32),
 Sub(f32, f32),
 Mul(f32, f32),
 Div(f32, f32),
}

struct MathRequest(Op);
impl Request<Option<f32>> for MathRequest {}

#[derive(Clone, Debug)]
struct MathEvent(Op, Option<f32>);
impl Event for MathEvent {}

struct MathRequestHandler(DefaultMediator);
impl RequestHandler<MathRequest, Option<f32>> for MathRequestHandler {
    fn handle(&mut self, req: MathRequest) -> Option<f32> {
        let result = match req.0 {
            Op::Add(a, b) => Some(a + b),
            Op::Sub(a, b) => Some(a - b),
            Op::Mul(a, b) => Some(a * b),
            Op::Div(a, b) => {
                if b == 0.0 { None } else { Some(a / b) }
            }
        };

        self.0.publish(MathEvent(req.0, result));
        result
    }
}

fn main() {
    let mut mediator = DefaultMediator::builder()
        .add_handler_deferred(|m| MathRequestHandler(m))
        .subscribe_fn(|event: MathEvent| {
           println!("{:?}", event);
         })
        .build();
}