Error when trying to implement a multiple_select

Hello, I’m trying to make a simple multiple selection in an appointment form, so users don’t have to search the ID for a medic, normally I searched a lot on how to implement a multiple_select and carefully followed everything on many forums, but no one gets this error:

no function clause matching in Phoenix.HTML.Tag.dasherize/1

My controller is as follows:

  defmodule Medica.AppointmentuController do
  use Medica.Web, :controller

  alias Medica.Appointment
  alias Medica.Medico

  def index(conn, _params) do
    appointments = Repo.all(Appointment)
    render(conn, "index.html", appointments: appointments)
  end

  def new(conn, _params) do
    changeset = Appointment.changeset(%Appointment{})
    medico = Repo.all from u in Medico, select: {u.id, u.nombre}
    render(conn, "new.html", medico: medico, changeset: changeset)
  end

  ...

end

New.html.eex

<h2 align="center">Modo Paciente</h2>
<h2>Reservar Nueva Hora</h2>

<%= render "forma.html", changeset: @changeset,
                        action: appointmentu_path(@conn, :create),
                        medico: @medico %>

and form.html.eex:

<%= form_for @changeset, @action,@medico, fn f -> %>
  <%= if @changeset.action do %>
    <div class="alert alert-danger">
      <p>Ingrese los datos correctamente o puede que la cita ya esté tomada.</p>
    </div>
  <% end %>

  <div class="form-group">
    <%= label f, :rut_paciente, class: "control-label" %>
    <%= text_input f, :rut_paciente, class: "form-control" %>
    <%= error_tag f, :rut_paciente %>
  </div>

  <div class="form-group">
    <%= label f, :fecha, class: "control-label" %>
    <%= date_input f, :fecha, class: "form-control" %>
    <%= error_tag f, :fecha %>
  </div>

  <div class="form-group">
    <%= label f, :id_medico, class: "control-label" %>
    <%= multiple_select f, :medico, Enum.map(@medico, &{&1.id, &1.nombre}) %>
    <%= error_tag f, :id_medico %>
  </div>

  <div class="form-group">
    <%= label f, :bloque, class: "control-label" %>
    <%= number_input f, :bloque, min: 1, class: "form-control" %>
    <%= error_tag f, :bloque %>
  </div>

  <div class="form-group">
    <%= label f, :descripcion, class: "control-label" %>
    <%= text_input f, :descripcion, class: "form-control" %>
    <%= error_tag f, :descripcion %>
  </div>

  <div class="form-group" align="center">
    <%= submit "✔", class: "btn btn-primary" %>
    <a class="btn btn-danger" href="/" role="button">✖</a>
  </div>

<% end %>

My models:

  schema "appointments" do
    field :rut_paciente, :string
    field :fecha, :date
    field :id_medico, :integer
    field :bloque, :integer
    field :descripcion, :string

    timestamps()
  end
  schema "medico" do
    field :nombre, :string
    field :apellido, :string
    field :especialidad, :string
  end

Screen for the error:

It’s not that easy without line numbers…

But my guess is here

&{&1.id, &1.nombre}

You are sending integer to multiple_select instead of atom or binary. Try to replace with

&{Integer.to_string(&1.id), &1.nombre}

First time using this forum, sorry about the lines. I tried replacing with your suggestion, but unfortunately it keeps giving me the same error.

No need to be sorry, I just meant it is not an obvious error :slight_smile:

Does it works if You remove this?

  <div class="form-group">
    <%= label f, :id_medico, class: "control-label" %>
    <%= multiple_select f, :medico, Enum.map(@medico, &{&1.id, &1.nombre}) %>
    <%= error_tag f, :id_medico %>
  </div>

It doesn’t, I guess it has something to do with the query?

Also, if I do

medico = Repo.all from u in Medico, select: {u.nombre}

I get,

no function clause matching in Keyword.delete_key/3

Although in both cases, it does get the values I want, but with these errors.

Maybe You can show Medico schema file with the validation part.

defmodule Medica.Medico do
  use Medica.Web, :model

  schema "medico" do
    field :nombre, :string
    field :apellido, :string
    field :especialidad, :string
  end

  @doc """
  Builds a changeset based on the `struct` and `params`.
  """
  def changeset(struct, params \\ %{}) do
    struct
    |> cast(params, [:nombre,:apellido,:especialidad])
    |> validate_required([:nombre,:apellido,:especialidad])
  end
end

This one right?

Yes, but what version of Phoenix do You use?

model is outdated now

With Phoenix 1.3, it looks like this

  use Ecto.Schema
  import Ecto.Changeset

1.3.2, but decided to use:
mix phoenix.new X
instead of
mix phx.new X
this created the new model, but as requested we needed to use the old model.

Oh, You should not use phoenix generator anymore, but phx

1 Like

It may be that, guess I have to create again from scratch with phx, thanks for your help.