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Accepted
juan gomez
Asked: 2020-06-17 06:34:10 +0800 CST 2020-06-17 06:34:10 +0800 CST

How to validate a select in rails?

  • 772

Hello, I want to validate that it is not empty, that I have to choose one of the options. Thank you.

view

<% if @reunion.errors %>
 <div class="error">
    <p>Se han encontrado los siguiente errores:</p>
    <ul>
       <% @reunion.errors.full_messages.each do |error| %>
       <li><%= error %></li>
      <% end %>
   </ul>
</div>

<div class = "row">
  <div class = "col-md-2"></div>
  <div class ="col-xs-12  col-sm-4 col-md-3">
    <label>Negocio</label>
    <%= select_tag "negocio", options_from_collection_for_select(@negocios, "id", "nombre"),
  class: "form-control", :include_blank => "Seleccione Pais"  %>
  </div>  
  <div class ="col-xs-12  col-sm-4 col-md-3">
    <label>region</label>
    <%= select_tag "region", "<option value="">Seleccione region</option>".html_safe, 
    class: "form-control" %>
  </div>
  <div class ="col-xs-12  col-sm-4 col-md-2">
    <label>ciudad</label>
    <%= select_tag "ciudad", "<option value="">Seleccione una ciudad</option>".html_safe, class: "form-control" %>
  </div>
  <div class = "col-md-2"></div>
</div>

<div class = "row">
  <div class = "col-md-2"></div>
  <div class ="col-xs-12  col-sm-4 col-md-2">
    <label>Planta</label>
    <%= select_tag "reunion[planta_id]","<option value="">Seleccione una planta</option>".html_safe, class: "form-control" %>
  </div>
</div>

controller

class ReunionesController < ApplicationController
  before_action :set_reunion, only: [:show, :edit, :update, :destroy]
  autocomplete  :centro_costo, :fullname, :full => true, :column_name => 'fullname'

  # GET /reuniones
  # GET /reuniones.json
  def index
    @reuniones = Reunion.all
    @negocios = Negocio.all
  end

  def select_region
    rs = Region.where(:negocio_id => params[:idnegocio]).order('nombre').all

    respond_to do |format|
      format.json { render json: rs }
      format.html
    end
  end

  def select_ciudad
    rs = Ciudad.where(:region_id => params[:idregion]).order('nombre').all

    respond_to do |format|
      format.json { render json: rs }
      format.html
    end
  end

  def select_planta
    rs = Planta.where(:ciudad_id => params[:idciudad]).order('nombre').all

    respond_to do |format|
      format.json { render json: rs }
      format.html
    end
  end

  # GET /reuniones/1
  # GET /reuniones/1.json
  def show
  end

  # GET /reuniones/new
  def new
    Time.zone = 'America/Bogota' 
    @reunion = Reunion.new(fecha_entrega: Time.zone.now.strftime("%d/%m/%Y"))
    @reunion.detalles_reuniones.build
    @negocios = Negocio.all #para javascript
  end

  # GET /reuniones/1/edit
  def edit
    @negocios = Negocio.all
  end

  # POST /reuniones
  # POST /reuniones.json
  def create  
    centro_costo = CentroCosto.find_by(fullname: reunion_params[:centro_costo_fullname])
    @reunion = Reunion.new(reunion_params)
    @reunion.centro_costo_id = centro_costo.id

    respond_to do |format|
      if @reunion.save
        format.html { redirect_to @reunion, notice: 'La reunión se creó correctamente.' }
        format.json { render :show, status: :created, location: @reunion }
      else
        @negocios = Negocio.all
        format.html { render :new }
        format.json { render json: @reunion.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /reuniones/1
  # PATCH/PUT /reuniones/1.json
  def update
    respond_to do |format|
      if @reunion.update(reunion_params)
        format.html { redirect_to @reunion, notice: 'La reunión se actualizó correctamente.' }
        format.json { render :show, status: :ok, location: @reunion }
      else
        @negocios = Negocio.all
        format.html { render :edit }
        format.json { render json: @reunion.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /reuniones/1
  # DELETE /reuniones/1.json
  def destroy
    @reunion.destroy
      respond_to do |format|
      format.html { redirect_to reuniones_url, notice: 'Reunión fue destruida con éxito.' }
      format.json { head :no_content }
    end
  end

  private
  # Use callbacks to share common setup or constraints between actions.
  def set_reunion
    @reunion = Reunion.find(params[:id])
  end

  # Never trust parameters from the scary internet, only allow the white list through.
  def reunion_params
    params.require(:reunion).permit(:hora_pedido, :fecha_pedido,
    :hora_inicio, :hora_final, :fecha_entrega, :observacion, :subtotal,
    :planta_id, :ubicacion,:centro_costo_fullname,:hora_entre,:nombre,
    #Aca esta el maestro de detalle.
    detalles_reuniones_attributes: [:id,:reunion_id, :cantidad, :valor, :producto_id,:_destroy])
  end
end

javascript

$(document).on('turbolinks:load', function(){
  // Empieza codigo para select anidados
  $("#negocio").change(function(event, data) {
    var id_negocio = $('select#negocio :selected').val();
    $.ajax({
      url: '/reuniones/select_region',
      dataType: "JSON",
      type: 'GET',
      data: { idnegocio: id_negocio },
      success: function(data) {
        var $select = $('#region');
        $select.empty().append('<option value="">Seleccione Region</option>');
        $(data).each(function (index, o) {    
          var $option = $("<option/>").attr("value", o.id).text(o.nombre);
          $select.append($option);
        });      
      }
    });

    // inicializar los selects
    var $select = $('#reunion_planta_id');
    $select.empty().append('<option value="">Seleccione ciudad</option>');
  });

  $("#region").change(function(event, data) {
    var id_region =  $('select#region :selected').val();
    $.ajax({
      url: '/reuniones/select_ciudad',
      dataType: "JSON",
      type: 'GET',
      data: { idregion: id_region },
      success: function(data) {
        var $select = $('#ciudad');
        $select.empty().append('<option value="">Seleccione una ciudad</option>');
        $(data).each(function (index, o) {    
          var $option = $("<option/>").attr("value", o.id).text(o.nombre);
          $select.append($option);
        });      
      }
    });
  });

  $("#ciudad").change(function(event, data) {
    var id_ciudad =  $('select#ciudad :selected').val();
    $.ajax({
      url: '/reuniones/select_planta',
      dataType: "JSON",
      type: 'GET',
      data: { idciudad: id_ciudad },
      success: function(data) {
        var $select = $('#reunion_planta_id');
        $select.empty().append('<option value="">Seleccione la planta</option>');
        $(data).each(function (index, o) {    
          var $option = $("<option/>").attr("value", o.id).text(o.nombre);
          $select.append($option);
        });      
      }
    });
  }); // Termina codigo para select anidado
}); //select reuniones fin de select

Reunion.rb

class Reunion < ApplicationRecord
  belongs_to :planta
end

What it shows in the updated log view.enter image description here enter image description here

javascript

1 Answers

  1. Best Answer

    How to validate a select in rails?

    Use validation presenceto validate that an attribute contains data (ie it is not blank), for example:

    class Reunion < ApplicationRecord
  belongs_to :planta

  validates :hora_pedido, presence: true
  validates :fecha_pedido, presence: true
end

    This will cause an error to be generated in said object when saving a type Reunionobject and, therefore, the record will not be saved. You can get that error by calling errorson the object.

    For example, in your case, I wouldn't change anything in your controller, your action createwould look the same, but running this line:

    if @reunion.save

    If any of the attributes that have validation presence: trueare blank (ie the user did not specify them), for example hora_pedido, an error with text similar to "Hora Pedido can't be blank"1 will be added to @reunion.errors.

    So, all you have to do is include a section in your view where this error is displayed (if it exists), for example, you could add this code to the top of your view 2 :

    <% if @reunion.errors %>
  <div class="error">
    <p>Se han encontrado los siguiente errores:</p>
    <ul>
      <% @reunion.errors.full_messages.each do |error| %>
        <li><%= error %></li>
      <% end %>
    </ul>
  </div>
<% end %>

    That code will show the errors that are found, if there are no errors, nothing will be shown.

    The only thing you have to do is add as many validations as you need in your model, the code to display the errors does not change anymore.

    To know the available validations I recommend you consult the Rails guides (content in English).

    1 Messages can be translated into config/locales/.

    2 Put the code and style it appropriately according to the design of your application.

    NoMethodError (undefined method `id' for nil:NilClass)

    This error is thrown because the parameter centro_costo_fullnameis empty (ie no value was provided in the form), which causes the value of centro_costoin createyour controller action to be nil:

    centro_costo = CentroCosto.find_by(fullname: reunion_params[:centro_costo_fullname])

    Therefore, trying to assign the value centro_costo.idto @reunion.centro_costo_idgenerates the error NoMethodError( centro_costobeing nilcannot respond to id).

    To correct it, we simply have to check if it centro_costocan respond to the method idbefore making the corresponding assignment, an action that we can achieve with try().

    Update the createcontroller action so that the line where the assignment is made is:

    @reunion.centro_costo_id = centro_costo.try(:id)

    So, if it's a valid centro_costoobject , it will be able to respond to and thus allocate the corresponding one; but if it is not, then it will assign .CentroCostoididnil

    I recommend that you also consider adding a validation layer with javascript / jQuery to offer a better user experience (as well as avoid sending data to the server with each user error).

    • 0