An open-source platform for microlearning through questions

Implementations:

• https://bitesized.info

Overview

Bite-Sized is an open-source system for testing, refreshing and reinforcing knowledge in 2 minutes or less.

• it emails you a question with a number of possible answers on a topic of your choosing
• you choose the right answer and get to see the explanations behind different options

Sample question

A large DynamoDB table has the following structure:
- `UserID` (PK)
- `ItemID` (SK)
- `ItemBarcode`
- other fields

What is the most efficient way of fetching a list of users (`UserID`) by `ItemBarcode`?

1. Perform a table Scan with `ItemBarcode` as the FilterExpression
2. Create a Local Secondary Index for `ItemBarcode` and perform Query with `ItemBarcode` as the key
3. Create a Global Secondary Index for `ItemBarcode` and perform Query with `ItemBarcode` as the only key

The correct answer:

A Global Secondary Index (GSI) is like a replica of the main table with different _Partition_ and _Secondary_ keys.
GSI items include the table Partition Key by default. All or some other attributes can be added as needed.
GSI's incur additional RCUs for maintenance.
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html

Features

Technical features:

• subscribes learners to topics
• sends questions with a selection of answers via email on a schedule
• displays the emailed question on a web page
• accepts answers as HTTP calls from email bodies
• displays detailed answers in response to the answer call
• one-click unsubscribe

Deployment

No deployment automation exists. Contact the maintainer to discuss.

Dev env

• Front-end: npm run build + git push to let [.github/workflows/deploy.yml] copy the built files to the S3 bucket.

Management

Adding, editing and removing questions

This is done by approved users only. The front-end enables ADD/EDIT buttons if x-bitie-token is present in the local storage.

Managing learner accounts

Manually in DynamoDB

Viewing stats

Every question record in DynamoDB has stats for pass/fail/viewed, but the numbers are write-only.

Tech stack and attribution

• Front-end: Vue
• CSS: https://v2.tailwindcss.com/docs/
• UI components: https://primevue.org/ and https://primevue.org/icons
• MD to HTML: https://marked.js.org
• Design ideas and code: https://flowbite.com
• Fonts: Roboto
• Graphics:
  • https://worldvectorlogo.com/
  • https://www.freepik.com/icon/cheese_4900716

Notes

• <Transition> is misbehaving, see https://stackoverflow.com/questions/68998731/vue-transition-with-tailwind
• MD XSS:
  • https://github.com/cujanovic/Markdown-XSS-Payloads/blob/master/Markdown-XSS-Payloads.txt
  • https://github.com/showdownjs/showdown/wiki/Markdown%27s-XSS-Vulnerability-(and-how-to-mitigate-it)
  • https://medium.com/taptuit/exploiting-xss-via-markdown-72a61e774bf8