cyoa

Exercise #3: Choose your own adventure

Choose Your Own Adventure is (was?) a series of books intended for children where as you read you would occasionally be given options about how you want to proceed. For instance, you might read about a boy walking in a cave when he stumbles across a dark passage or a ladder leading to an upper level and the reader will be presented with two options like:

• Turn to page 44 to go up the ladder.
• Turn to page 87 to venture down the dark passage.

The goal of this exercise is to recreate this experience via a web application where each page will be a portion of the story, and at the end of every page the user will be given a series of options to choose from (or be told that they have reached the end of that particular story arc).

Stories will be provided via a JSON file with the following format:

{
  // Each story arc will have a unique key that represents
  // the name of that particular arc.
  "story-arc": {
    "title": "A title for that story arc. Think of it like a chapter title.",
    "story": [
      "A series of paragraphs, each represented as a string in a slice.",
      "This is a new paragraph in this particular story arc."
    ],
    // Options will be empty if it is the end of that
    // particular story arc. Otherwise it will have one or
    // more JSON objects that represent an "option" that the
    // reader has at the end of a story arc.
    "options": [
      {
        "text": "the text to render for this option. eg 'venture down the dark passage'",
        "arc": "the name of the story arc to navigate to. This will match the story-arc key at the very root of the JSON document"
      }
    ]
  },
  ...
}

See gopher.json for a real example of a JSON story. I find that seeing the real JSON file really helps answer any confusion or questions about the JSON format.

You are welcome to design the code however you want. You can put everything in a single main package, or you can break the story into its own package and use that when creating your http handlers.

The only real requirements are:

1. Use the html/template package to create your HTML pages. Part of the purpose of this exercise is to get practice using this package.
2. Create an http.Handler to handle the web requests instead of a handler function.
3. Use the encoding/json package to decode the JSON file. You are welcome to try out third party packages afterwards, but I recommend starting here.

A few things worth noting:

• Stories could be cyclical if a user chooses options that keep leading to the same place. This isn't likely to cause issues, but keep it in mind.
• For simplicity, all stories will have a story arc named "intro" that is where the story starts. That is, every JSON file will have a key with the value intro and this is where your story should start.
• Matt Holt's JSON-to-Go is a really handy tool when working with JSON in Go! Check it out - https://mholt.github.io/json-to-go/

Bonus

As a bonus exercises you can also:

1. Create a command-line version of our Choose Your Own Adventure application where stories are printed out to the terminal and options are picked via typing in numbers ("Press 1 to venture ...").
2. Consider how you would alter your program in order to support stories starting form a story-defined arc. That is, what if all stories didn't start on an arc named intro? How would you redesign your program or restructure the JSON? This bonus exercises is meant to be as much of a thought exercise as an actual coding one.