Phoenix: Add has_flash? functions.

[yaBliznyk]

How you look to add functions to controller?

@doc """
Return boolean conn has flashes
"""
def has_flash?(conn) do
  get_flash(conn) !== %{}
end

@doc """
Return boolean conn has flash by key
"""
def has_flash?(conn, key) do
  get_flash(conn) |> Map.has_key?(flash_key(key))
end

and add

# Import convenience functions from controllers
  import Phoenix.Controller, only: [
    get_csrf_token: 0, has_flash?: 1,
    get_flash: 2, view_module: 1
  ]

Using like this

<% if has_flash?(@conn) do %>
  <p class="alert alert-info" role="alert"><%= get_flash(@conn, :info) %></p>
  <p class="alert alert-danger" role="alert"><%= get_flash(@conn, :error) %></p>
<% end %>

[josevalim]

II am not sure it would help you with anything given that checking if there is a flash message does not guarantee get_flash(@conn, :info) will return something.

[yaBliznyk]

<% if has_flash?(@conn, :info) do %>
  <p class="alert alert-info" role="alert"><%= get_flash(@conn, :info) %></p>
<% end %>

May be like this?

http://joxi.ru/EA4axDRhDlvwzr

[josevalim]

Which then I would just write as:

<% if info = get_flash(@conn, :info) do %>
  <p class="alert alert-info" role="alert"><%= info %></p>
<% end %>

:)

[yaBliznyk]

+1!! It is a great idea!

[derekhubbard]

@josevalim's solution didn't work for me at first, and then I realized you need to eval the if expression. Here's the updated version that works:

<%= if info = get_flash(@conn, :info) do %>
  <p class="alert alert-info" role="alert"><%= info %></p>
<% end %>

[guilhermeyo]

@derekhubbard I think answer of @cpgo go to help you.

https://elixirforum.com/t/check-for-error-and-info-alert-in-phoenix/1984/3