Slack Morphism for Rust

Slack Morphism is a modern client library for Slack Web/Events API and Block Kit.

Intro and motivation

• Type-safety: All of the models, API and Block Kit support in Slack Morphism is well-typed.
• Easy to use: The library depends only on familiar for Rust developers principles and libraries like Serde, hyper, futures.
• Async: Using latest Rust async/.await language features and libraries, the library provides access to all of the functions in asynchronous manner

Getting Started

Cargo.toml dependencies example:

[dependencies]
slack-morphism="0.2"
slack-morphism-models="0.2"

All imports you need:

use slack_morphism::*; // access to network/client functions
use slack_morphism::api::*; // Slack Web API methods (chat, users, views, etc)
use slack_morphism::listener::*; // Slack Events API listener (routes) implementation
use slack_morphism_models::*; // common Slack models like SlackUser, etc and macros
use slack_morphism_models::blocks::*; // Slack Block Kit models
use slack_morphism_models::events::*; // Slack Events Models

Slack Web API client

Create a client instance:

use slack_morphism::*;

let client = SlackClient::new();

Make Web API methods calls

For most of Slack Web API methods (except for OAuth methods, Incoming Webhooks and event replies) you need a Slack token to make a call. For simple bots you can have it in your config files, or you can obtain workspace tokens using Slack OAuth.

In the example below, we’re using a hardcoded Slack token, but don’t do that for your production bots and apps. You should securely and properly store all of Slack tokens.

use slack_morphism::*;
use slack_morphism::api::*;
use slack_morphism_models::*;

async fn example() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {

let client = SlackClient::new();

// Create our Slack API token
let token_value: SlackApiTokenValue = "xoxb-89.....".into();
let token: SlackApiToken = SlackApiToken::new(token_value);

// Create a Slack session with this token
let session = client.open_session(&token);

// Make your first API call (which is `api.test` here)
let test: SlackApiTestResponse = session
.api_test(&SlackApiTestRequest::new().with_foo("Test".into()))
.await?;

// Send a simple text message
let post_chat_req =
SlackApiChatPostMessageRequest::new("#general".into(),
SlackMessageContent::new().with_text("Hey there!".into())
);

let post_chat_resp = session.chat_post_message(&post_chat_req).await?;

Ok(())
}

Pagination support

Some Web API methods defines cursors and pagination, to give you an ability to load a lot of data continually (using batching and continually making many requests).

Examples: conversations.history, conversations.list, users.list, ...

To help with those methods Slack Morphism provides additional a “scroller” implementation, which deal with all scrolling/batching requests for you.

For example for users.list:

use slack_morphism::*;
use slack_morphism::api::*;
use slack_morphism_models::*;
use std::time::Duration;

async fn example() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {

let client = SlackClient::new();
let token_value: SlackApiTokenValue = "xoxb-89.....".into();
let token: SlackApiToken = SlackApiToken::new(token_value);
let session = client.open_session(&token);

// Create a first request and specify a batch limit:
let scroller_req: SlackApiUsersListRequest = SlackApiUsersListRequest::new().with_limit(5);

// Create a scroller from this request
let scroller = scroller_req.scroller();

// Option 1: Create a Rust Futures Stream from this scroller and use it
use futures::stream::BoxStream;
use futures::TryStreamExt;

let mut items_stream = scroller.to_items_stream(&session);
while let Some(items) = items_stream.try_next().await? {
println!("users batch: {:#?}", items);
}

// Option 2: Collect all of the data in a vector (which internally uses the same approach above)
let collected_members: Vec<SlackUser> = scroller
.collect_items_stream(&session, Duration::from_millis(1000))
.await?;
Ok(())
}

Block Kit support

To support Slack Block Kit rich messages and views, the library provides:

• Well-typed models
• Macros to help build blocks, block elements

Let’s take some very simple block example:

{
"blocks": [
{
"type": "section",
"text": {
"type": "mrkdwn",
"text": "A message *with some bold text* and _some italicized text_."
}
}
]
}

Now, let’s look at how it looks with type-safe code using Slack Morphism Blocks macro support:

use slack_morphism_models::*;
use slack_morphism_models::blocks::*;

let blocks : Vec<SlackBlock> = slack_blocks![
some_into(
SlackSectionBlock::new()
.with_text(md!("A message *with some bold text* and _some italicized text_."))
)
];

Let’s look at another more complex example for welcoming message:

use slack_morphism::*;
use slack_morphism::api::*;
use slack_morphism_models::*;
use slack_morphism_models::blocks::*;

async fn example() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {

use std::time::Duration;
use rsb_derive::Builder;

let client = SlackClient::new();
let token_value: SlackApiTokenValue = "xoxb-89.....".into();
let token: SlackApiToken = SlackApiToken::new(token_value);
let session = client.open_session(&token);

// Our welcome message params as a struct
#[derive(Debug, Clone, Builder)]
pub struct WelcomeMessageTemplateParams {
pub user_id: SlackUserId,
}

// Define our welcome message template using block macros, a trait and models from the library
impl SlackMessageTemplate for WelcomeMessageTemplateParams {
fn render_template(&self) -> SlackMessageContent {
SlackMessageContent::new()
.with_text(format!("Hey {}", self.user_id.to_slack_format()))
.with_blocks(slack_blocks![
some_into(
SlackSectionBlock::new()
.with_text(md!("Hey {}", self.user_id.to_slack_format()))
),
some_into(SlackDividerBlock::new()),
some_into(SlackImageBlock::new(
"https://www.gstatic.com/webp/gallery3/2_webp_ll.png".into(),
"Test Image".into()
)),
some_into(SlackActionsBlock::new(slack_blocks![some_into(
SlackBlockButtonElement::new(
"simple-message-button".into(),
pt!("Simple button text")
)
)]))
])
}
}

// Use it
let message = WelcomeMessageTemplateParams::new("some-slack-uid".into());

let post_chat_req =
SlackApiChatPostMessageRequest::new("#general".into(), message.render_template());

Ok(())
}

Look other examples in examples/templates.rs

Events API and OAuth support

The library provides route implementation in SlackClientEventsListener based on Hyper/Tokio for:

• Push Events
• Interaction Events
• Command Events
• OAuth v2 redirects and client functions

You can chain all of the routes using chain_service_routes_fn from the library.

Also the library provides Slack events signature verifier (SlackEventSignatureVerifier) (which is already integrated in the routes implementation for you). All you need is provide your client id and secret configuration to route implementation.

Look at the examples/test_server sources for the details.

Limitations

Slack Morphism doesn't provide:

• RTM API (the usage of which is slowly declining in favour of Events API)
• Legacy Web/Events API methods and models (like Slack Message attachments, which should be replaced with Slack Blocks)