Email Validation

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

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Email Validation

Most applications and websites with users have a sign up form with an email input.

Generally, we validate this input to ensure that users enter a valid email.

You are going to build an Email.validate/1 function which checks if an email address is valid or not.

Email.valid?("mail@mail.com")
true

Email.valid?("mail.com")
false

For the sake of this exercise, an email is valid if it is in the format string@string.string. Be aware, this is not sufficient for true email validation where not all characters are allowed.

Hint

Consider using Regex.match/2.

Example Solution

defmodule Email do
  def valid?(email) do
    Regex.match?(~r/\w+\@\w+\.\w+/, email)
  end
end

Implement the Email module as documented.

defmodule Email do
  @moduledoc """
  Documentation for `Email`
  """

  @doc """
  Checks if an email is valid.

  ## Examples

    iex> Email.valid?("mail@mail.com")
    true

    iex> Email.valid?("string@string.string")
    true

    iex> Email.valid?("string")
    false

    iex> Email.valid?(".string")
    false

    iex> Email.valid?("string.string")
    false

    iex> Email.valid?("string@string")
    false

    iex> Email.valid?("string@string.")
    false
  """
  def valid?(email) do
  end
end

Mark As Completed

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

save_name =
  case Path.basename(__DIR__) do
    "reading" -> "email_validation_reading"
    "exercises" -> "email_validation_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 email-validation-exercise
$ git add .
$ git commit -m "finish email validation exercise"
$ git push origin email-validation-exercise

Create a pull request from your email-validation-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.

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