A Pomodoro Timer was one of the first projects I did as part of the TheOdinProjects Curriculum in 2019. The timer just uses Javascript and some basic HTML/CSS to display the time in a fashionable way. Since building the timer myself, I have been using the Pomodoro study method to focus on my studies and to be more productive.

It should still be visitable via Github pages

Helping a friend

A few weeks ago a friend of mine mentioned his problems to stay productive and focus on studying for his upcoming exams. He explained that his time is often spend on games or procrastination. I told him about my usage of the pomodoro technique and he seemed interested in using it himself. At that point I thought about studying together to encourage each other. Wouldn’t it be cool, to have a timer bot for each study session?

Then I looked into Discord bots and started to work on one.

What should the bot do?

• set custom times and count down
• notify each user in the voice chat about the time
• play a sound after finishing a session

Discord API wrapper

My search did not last that long. After a few minutes, I found a well maintained gem for the Discord API, written in Ruby. This seemed to perfectly match my preferences. Here is a link to the gem.

Saving the bot token

Discord API calls need a token for your application/Bot to work. There are different methods on saving the bot token locally, without exposing it on the Internet. First I used a config.yaml file to store my token and .gitignore it.

But to deploy it via Heroku, the bot token is stored in an environment variable on the machine. Just calling the bot with

 bot = Discordrb::Bot.new token: ENV['token']

does the trick.

Implementing a response

My bot builds on the basic Ping example, which should return an message, after recieving an special message. So I used the pom command to respond to a user wanting to start a session.

 bot.message(start_with: 'pom', in: '#bot-channel') do 
  |event| 
 end

The bot just respons to calls in the #bot-channel to reduce spam.

The event block

Before stripping the pom message for the amount of minutes a user wants to study, the bot checks if the user is currently using a voice channel. That way I don’t have to deal with errors if the bot wants to play a sound without knowing in which voice channel to join.

 if channel.nil?
   event.respond 'You have to be connected to a voice channel.'
   event.respond 'Try again after you joined a channel!'
 else
   minutes = event.content.split(/ /)[1].to_i
   ...
 end

The event block contains every method that I need to make the timer work. The current channel can be called with

 channel = event.user.voice_channel

and to pm the users in the voice channel, that use the bot I can just iterate over the channel.users array.

 channel.users.each do |user|
   user.pm("Starting Pomodoro for #{minutes} minutes")
 end

Timer loop

My bot set adds the minutes of the pom call to the current time and just checks every minute, if the time is reached. Maybe there is a more efficiennt example of a timer loop, but I just put my ruby loop to sleep for 60 seconds.

 pomodoro_time = Time.new + (minutes * 60)
 ...
 until current_time >= pomodoro_time
   sleep(60)
   current_time = Time.new
 end

Play a sound!

After the time loop reaches the time set by the user, the bot joins the voice channel and plays a sound. In my case it a doorbell ring!

 bot.voice_connect(channel)
 voice_bot = event.voice
 voice_bot.play_file('data/doorbell-1.mp3')
 voice_bot.destroy

And once again the event block is here to save my time.

Input validation? I don’t need that

In my case, this bot is used in a private Discord server and I did not feel like adding input validation, like starting more than one session. I trust my friends, that they won’t abuse this bot.

Final thoughts

This was a really fun side project and it was really easy to work with the Discordrb gem. Also the documentation helped a lot. If you wanna improvev this bot feel free to clone my repo or build one for yourself. The sky is the limit! Onto my next project. Actually writing my BA thesis…