Challenge: Joke App

Overview

Your challenge is to build a simple joke application that implements basic CRUD operations (Create, Read, Update, Delete) using Holochain’s Actions and Entries model.

Key Learning Goals

Through this challenge, you’ll gain practical experience with:

  • Working with Entry and Action types
  • Understanding how data is referenced through hashes
  • Implementing basic CRUD operations
  • Experiencing Holochain’s immutable history model

Getting Started

The starter code and detailed instructions are available in the challenge repository:

Joke App Challenge Repository

You can view the difference between the starter code and the sample solution here.

Quick Setup

# Clone the repository
git clone https://github.com/CodeWithJV/holochain-challenge-1
cd holochain-challenge-1

# Enter the nix shell for development
nix develop

Tips

  • Take time to understand the structure of the project before diving into implementation
  • Pay attention to how ActionHash and EntryHash are used differently
  • Test your implementation at each step using the provided test suite
  • Remember that in Holochain, entries are never truly deleted - they’re marked as deleted

Requirements

  1. Create a Joke Entry Type

    • Define a Joke entry type with fields for content and optional metadata
    • Implement a function to create new jokes

  2. Implement Read Operations

    • Create a function to get a joke by its ActionHash
    • Add a function to get a joke by its EntryHash
    • Observe the differences between these two approaches

  3. Update Functionality

    • Implement a function to update an existing joke
    • Ensure only the original author can update their jokes
    • Understand how updates create new records while preserving history

  4. Delete Operation

    • Create a function to delete jokes
    • Understand that deletion in Holochain marks entries as deleted rather than removing them