pid1/deno-hello-world

Send a greeting to channel

Hello World

This automation demonstrates sending a greeting to channel.

Guide Outline:

• Setup
  • Install the Slack CLI
  • Clone the Sample
• Create a Link Trigger
• Running Your Project Locally
• Testing
• Deploying Your App
  • Viewing Activity Logs
• Project Structure
• Resources

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Setup

Before getting started, first make sure you have a development workspace where you have permission to install apps. Please note that the features in this project require that the workspace be part of a Slack paid plan.

Install the Slack CLI

To use this sample, you need to install and configure the Slack CLI. Step-by-step instructions can be found in our Quickstart Guide.

Clone the Sample

Start by cloning this repository:

# Clone this project onto your machine
$ slack create hello-world -t slack-samples/deno-hello-world

# Change into the project directory
$ cd hello-world

Running Your Project Locally

While building your app, you can see your changes appear in your workspace in real-time with slack run. You'll know an app is the development version if the name has the string (local) appended.

# Run app locally
$ slack run

Connected, awaiting events

To stop running locally, press <CTRL> + C to end the process.

Creating Triggers

Triggers are what cause workflows to run. These triggers can be invoked by a user, or automatically as a response to an event within Slack.

When you run or deploy your project for the first time, the CLI will prompt you to create a trigger if one is found in the triggers/ directory. For any subsequent triggers added to the application, each must be manually added using the trigger create command.

When creating triggers, you must select the workspace and environment that you'd like to create the trigger in. Each workspace can have a local development version (denoted by (local)), as well as a deployed version. Triggers created in a local environment will only be available to use when running the application locally.

Link Triggers

A link trigger is a type of trigger that generates a Shortcut URL which, when posted in a channel or added as a bookmark, becomes a link. When clicked, the link trigger will run the associated workflow.

Link triggers are unique to each installed version of your app. This means that Shortcut URLs will be different across each workspace, as well as between locally run and deployed apps.

With link triggers, after selecting a workspace and environment, the output provided will include a Shortcut URL. Copy and paste this URL into a channel as a message, or add it as a bookmark in a channel of the workspace you selected. Interacting with this link will run the associated workflow.

Note: triggers won't run the workflow unless the app is either running locally or deployed!

Manual Trigger Creation

To manually create a trigger, use the following command:

$ slack trigger create --trigger-def triggers/greeting_trigger.ts

Datastores

For storing data related to your app, datastores offer secure storage on Slack infrastructure. The use of a datastore requires the datastore:write/datastore:read scopes to be present in your manifest.

Testing

For an example of how to test a function, see functions/greeting_function_test.ts. Test filenames should be suffixed with _test.

Run all tests with deno test:

$ deno test

Deploying Your App

Once development is complete, deploy the app to Slack infrastructure using slack deploy:

$ slack deploy

When deploying for the first time, you'll be prompted to create a new link trigger for the deployed version of your app. When that trigger is invoked, the workflow should run just as it did when developing locally (but without requiring your server to be running).

Viewing Activity Logs

Activity logs of your application can be viewed live and as they occur with the following command:

$ slack activity --tail

Project Structure

.slack/

Contains apps.dev.json and apps.json, which include installation details for development and deployed apps.

datastores/

Datastores securely store data for your application on Slack infrastructure. Required scopes to use datastores include datastore:write and datastore:read.

functions/

Functions are reusable building blocks of automation that accept inputs, perform calculations, and provide outputs. Functions can be used independently or as steps in workflows.

triggers/

Triggers determine when workflows are run. A trigger file describes the scenario in which a workflow should be run, such as a user pressing a button or when a specific event occurs.

workflows/

A workflow is a set of steps (functions) that are executed in order.

Workflows can be configured to run without user input or they can collect input by beginning with a form before continuing to the next step.

manifest.ts

The app manifest contains the app's configuration. This file defines attributes like app name and description.

slack.json

Used by the CLI to interact with the project's SDK dependencies. It contains script hooks that are executed by the CLI and implemented by the SDK.

Resources

To learn more about developing automations on Slack, visit the following:

• Automation Overview
• CLI Quick Reference
• Samples and Templates