Colored-bar attachment

Use a legacy attachment when an existing integration needs a colored side bar. Prefer regular blocks for new layouts.

Output

Local preview of the selected language’s tested example. Slack client appearance may differ; controls here do not send requests.

Disk usage warning

⚠️ /var is at 87% capacity on prod-db-1.

Serialized output

{
  "channel": "#alerts",
  "mrkdwn": true,
  "attachments": [
    {
      "blocks": [
        {
          "type": "section",
          "block_id": "<generated-block-id>",
          "text": {
            "type": "mrkdwn",
            "text": ":warning: `/var` is at 87% capacity on `prod-db-1`."
          }
        }
      ],
      "color": "#ffff00"
    }
  ],
  "text": "Disk usage warning"
}

Code

Slack has long deprecated message attachments, but they're still the only way to get the colored vertical bar on the left of a message. slackblocks supports them when you really need that styling:

from slackblocks import (
    Attachment,
    Color,
    Message,
    SectionBlock,
)

msg = Message(
    channel="#alerts",
    text="Disk usage warning",
    attachments=[
        Attachment(
            color=Color.YELLOW,
            blocks=[SectionBlock(":warning: `/var` is at 87% capacity on `prod-db-1`.")],
        ),
    ],
)
print(msg.json())

Prefer plain blocks where possible — Slack may drop attachment support in the future.

import * as S from "@nicklambourne/slackblocks";

const message = S.Message().channel("C1").text("Checks passed").attachments(
  S.Attachment().color("good").blocks(S.SectionBlock().text("All checks passed")),
).build();
console.log(JSON.stringify(message));

package main

import (
	"encoding/json"
	s "github.com/nicklambourne/slackblocks/go/v3"
	"os"
)

func main() {
	value, err := s.NewMessage().Channel("C1").Text("Checks passed").Attachments(
		s.NewAttachment().Color("good").Blocks(s.NewSectionBlock().Text("All checks passed")),
	).Build()
	if err != nil {
		panic(err)
	}
	if err := json.NewEncoder(os.Stdout).Encode(value); err != nil {
		panic(err)
	}
}

import io.github.nicklambourne.slackblocks.*;
import io.github.nicklambourne.slackblocks.block.*;
import io.github.nicklambourne.slackblocks.component.*;
import io.github.nicklambourne.slackblocks.element.*;
import io.github.nicklambourne.slackblocks.object.*;
import io.github.nicklambourne.slackblocks.payload.*;
import java.util.List;
import java.util.Map;

public final class Recipe {
  public static void main(String[] args) throws Exception {
    var value = MessagePayload.builder().channel("C1").text("Checks passed").attachments(
    Attachment.builder().color("good").blocks(SectionBlock.builder().markdownText("All checks passed").build()).build()).build();
    System.out.println(value.toJson());
  }
}

using System;
using System.Collections.Generic;
using Slackblocks;
using Slackblocks.Blocks;
using Slackblocks.Components;
using Slackblocks.Elements;
using Slackblocks.Objects;
using Slackblocks.Payloads;

var value = new MessagePayload("C1", text: "Checks passed", attachments: [
    new Attachment(blocks: [new SectionBlock("All checks passed")], color: "good"),
]);
Console.WriteLine(value.ToJson());

require "slackblocks"
include Slackblocks

value = MessagePayload.new(channel: "C1", text: "Checks passed", attachments: [
  Attachment.new(color: "good", blocks: [SectionBlock.new(text: "All checks passed")])
])
puts value.to_json

Attachments are a legacy Slack feature. AttachmentColor supports semantic colors, named constants and checked six-digit hex parsing.

use slackblocks::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let attachment = Attachment::builder()
        .color(AttachmentColor::YELLOW)
        .block(
            SectionBlock::builder()
                .text(":warning: Disk usage is at 87%.")
                .build()?,
        )
        .build()?;
    let message = MessagePayload::builder("C01234567")
        .text("Disk usage warning")
        .attachment(attachment)
        .build()?;
    println!("{}", serde_json::to_string(&message)?);
    Ok(())
}

<?php

declare(strict_types=1);

require 'vendor/autoload.php';

use Slackblocks as S;

$message = new S\MessagePayload(channel: 'C1', text: 'Deployment passed', attachments: [
    new S\Attachment(blocks: [new S\SectionBlock('All checks passed')], color: S\Color::GOOD),
]);
echo $message->toJson();

alias Slackblocks.{Message, Attachment, Color, Blocks.Section}
attachment = Attachment.new!(color: Color.named!(:good), blocks: [Section.new!(text: "All checks passed")])
Message.new!(channel: "C1", text: "Checks passed", attachments: [attachment]) |> Slackblocks.to_map!()

{-# LANGUAGE OverloadedStrings #-}

import Data.Aeson (encode)
import qualified Data.Map.Strict as Map
import Slackblocks

example = do
  text <- buildMarkdownText (markdownText "All checks passed")
  section <- buildSectionBlock (sectionBlock {sectionBlockText = Just (markdownTextAsText text)})
  notice <- buildAttachment ((attachment [sectionBlockAsBlock section]) {attachmentColor = Just (colorText (namedColor Good))})
  buildMessagePayload ((messagePayload "C1") {messagePayloadText = Just "Checks passed", messagePayloadAttachments = Just [notice]})

Output

Code​

Code