Shopping List

Mix.install([
  {:jason, "~> 1.4"},
  {:kino, "~> 0.8.0", override: true},
  {:youtube, github: "brooklinjazz/youtube"},
  {:hidden_cell, github: "brooklinjazz/hidden_cell"}
])

Navigation

Return Home Report An Issue

Setup

Ensure you type the ea keyboard shortcut to evaluate all Elixir cells before starting. Alternatively you can evaluate the Elixir cells as you read.

Text Shopping List

You are creating a shopping list app. Users have the ability to add items into their shopping_cart. Each item is represented as a string.

In the Elixir cells below, use ++ and -- to add the items shown.

• Add "grapes", "walnuts", and "apples" to the shopping_cart
• Add "blueberries", "chocolate", and "pizza" to the shopping_cart.
• Remove "grapes" and "walnuts" from the shopping_cart
• Add three "banana"s to the shopping_cart

Example solution

shopping_cart = []

shopping_cart = shopping_cart ++ ["grapes", "walnuts", "apples"]
shopping_cart = shopping_cart ++ ["blueberries", "chocolate", "pizza"]
shopping_cart = shopping_cart -- ["grapes", "walnuts"]
shopping_cart = shopping_cart ++ ["banana", "banana", "banana"]

Enter your solution below.

Text Shopping List With Quantities

Users of your shopping list app have asked that they be able to include the quantity of each item to make adding many items easier.

In the Elixir cell below, use a keyword list in the format [item: quantity] to add or remove items from the shopping_cart

• Add 1 milk and 12 eggs
• Add 2 bars_of_butter and 10 candies
• Remove 2 bars_of_butter
• Remove 5 candies (Notice 5 and not 10!).

Example solution

shopping_cart = []

shopping_cart = shopping_cart ++ [milk: 1, eggs: 12]
shopping_cart = shopping_cart ++ [bars_of_butter: 2, candies: 10]
shopping_cart = shopping_cart -- [bars_of_butter: 2]
shopping_cart = shopping_cart -- [candies: 10]
shopping_cart = shopping_cart ++ [candies: 5]

Mark As Completed

file_name = Path.basename(Regex.replace(~r/#.+/, __ENV__.file, ""), ".livemd")

save_name =
  case Path.basename(__DIR__) do
    "reading" -> "shopping_list_reading"
    "exercises" -> "shopping_list_exercise"
  end

progress_path = __DIR__ <> "/../progress.json"
existing_progress = File.read!(progress_path) |> Jason.decode!()

default = Map.get(existing_progress, save_name, false)

form =
  Kino.Control.form(
    [
      completed: input = Kino.Input.checkbox("Mark As Completed", default: default)
    ],
    report_changes: true
  )

Task.async(fn ->
  for %{data: %{completed: completed}} <- Kino.Control.stream(form) do
    File.write!(
      progress_path,
      Jason.encode!(Map.put(existing_progress, save_name, completed), pretty: true)
    )
  end
end)

form

Commit Your Progress

Run the following in your command line from the curriculum folder to track and save your progress in a Git commit. Ensure that you do not already have undesired or unrelated changes by running git status or by checking the source control tab in Visual Studio Code.

$ git checkout -b shopping-list-exercise
$ git add .
$ git commit -m "finish shopping list exercise"
$ git push origin shopping-list-exercise

Create a pull request from your shopping-list-exercise branch to your solutions branch. Please do not create a pull request to the DockYard Academy repository as this will spam our PR tracker.

DockYard Academy Students Only:

Notify your teacher by including @BrooklinJazz in your PR description to get feedback. You (or your teacher) may merge your PR into your solutions branch after review.

If you are interested in joining the next academy cohort, sign up here to receive more news when it is available.

Up Next