One-time flash messages for Nex applications.

Flash messages are stored in the session and automatically cleared after being read on the next page render. Perfect for post-action notifications like "Saved successfully!" or "Invalid credentials."

Usage

# In an action — set a flash message
def create(%{"title" => title}) do
  # ... create logic ...
  Nex.Flash.put(:info, "Post created successfully!")
  {:redirect, "/posts"}
end

def login(%{"email" => email, "password" => password}) do
  case authenticate(email, password) do
    {:ok, _user} ->
      Nex.Flash.put(:success, "Welcome back!")
      {:redirect, "/dashboard"}
    {:error, _} ->
      Nex.Flash.put(:error, "Invalid email or password.")
      {:redirect, "/login"}
  end
end

# In mount/1 — read and clear flash messages
def mount(_params) do
  flash = Nex.Flash.pop_all()
  %{flash: flash}
end

# In your layout or page template
~H"""
<%= if @flash[:error] do %>
  <div class="alert alert-error">{@flash[:error]}</div>
<% end %>
<%= if @flash[:info] do %>
  <div class="alert alert-info">{@flash[:info]}</div>
<% end %>
"""

Flash Types

Any atom key is valid. Common conventions:

• :info — neutral informational message
• :success — positive confirmation
• :error — error or failure
• :warning — caution message