Slack の中の人が教える Slack API ハンズオン in 福岡

Cargo.toml

[package]
name = "rust-slack-app"
version = "0.1.0"
authors = ["yoshihitoh <yoshihito.arih@gmail.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
slack = "0.22"

handler.rs

use slack::api::MessageStandard;
use slack::{Event, EventHandler, Message, RtmClient};

pub struct KeywordHandler {
    keywords: Vec<String>,
}

impl From<Vec<String>> for KeywordHandler {
    fn from(keywords: Vec<String>) -> Self {
        KeywordHandler { keywords }
    }
}

impl EventHandler for KeywordHandler {
    fn on_event(&mut self, cli: &RtmClient, event: Event) {
        dbg!(&event);
        match event {
            Event::Message(message) => self.handle_message(cli, *message),
            _ => (),
        }
    }

    #[allow(unused_variables)]
    fn on_close(&mut self, cli: &RtmClient) {
        println!("bye!");
    }

    #[allow(unused_variables)]
    fn on_connect(&mut self, cli: &RtmClient) {
        println!("rust-slack bot is ready!");
    }
}

impl KeywordHandler {
    fn handle_message(&self, cli: &RtmClient, message: Message) {
        match message {
            Message::Standard(standard) => self.handle_standard_message(cli, standard),
            _ => (),
        }
    }

    fn handle_standard_message(&self, cli: &RtmClient, standard: MessageStandard) {
        // メッセージ本文にキーワードを含んでるかチェック
        let text = standard.text.as_ref().map(|s| s.as_str()).unwrap_or("");
        if !self.keyword_matches(text) {
            return;
        }

        // 反応する
        let channel = standard.channel.unwrap_or("".to_string());
        let user = standard.user.unwrap_or("".to_string());
        let reply = format!("Hi <@{}>", user);  // <@ユーザID> の形式で指定するとメンションになる
        cli.sender().send_message(&channel, &reply);
    }

    fn keyword_matches(&self, text: &str) -> bool {
        self.keywords.iter().any(|kw| text.contains(kw))
    }
}

main.rs

use std::env;

use slack::RtmClient;

mod handler;
use handler::KeywordHandler;

fn main() -> Result<(), slack::error::Error> {
    let api_key = api_key();
    let mut handler = KeywordHandler::from(vec!["Hello".to_string()]);
    RtmClient::login_and_run(&api_key, &mut handler)
}

fn api_key() -> String {
    // APIトークンは環境変数 SLACK_API_TOKEN から取得する
    env::var("SLACK_API_TOKEN").expect("Set API token to `SLACK_API_TOKEN`")
}