Question

The problem I have is the select box in my view does not maintain the value selected if a validation error occurs.

I have business and category relationship which has a many to many association

category.rb

class Category < ActiveRecord::Base
    has_and_belongs_to_many :businesses

business.rb

class Business < ActiveRecord::Base
    has_and_belongs_to_many :categories

In my view I have a select field

<%= f.select(:category_tokens, Category.all.collect {|c| [ c.name, c.id ] }, { :include_blank => "Select Category", :selected => params['category'] }}) %>

I can access the business categories in the console using business.categories which returns and array.

In my view to troubleshoot the params I’ve added.

<%= @business.categories %>
<%= @business.attributes.inspect %>
<%= @business.user.attributes.inspect %>

The output for these shows provides the following

[#<Category id: 2, name: "kitchen renovations", created_at: "2012-10-19 14:16:52", updated_at: "2012-10-19 14:16:52">]

{"id"=>nil, "business_name"=>"", ... additional attributes}

{"id"=>nil, "email"=>"", ... additional attributes}

The params hash looks like this

Processing by BusinessesController#create as HTML
Parameters: {"utf8"=>"✓",
"authenticity_token"=>"fVz1mJZI8QT/HYKRph8YTvzRec0IVV0RS55v5QD5SL0=", 
"business"=>{"category_tokens"=>"2", 
"location"=>"", "service_area"=>"20", 
"business_name"=>"", "abn_number"=>"", 
"business_description"=>"", 
"address"=>"", "suburb"=>"", 
"notification_type"=>"", 
"user_attributes"=>{"first_name"=>"", "phone"=>"", "email"=>"", "password"=>"[FILTERED]", "password_confirmation"=>"[FILTERED]"}}, "commit"=>"Sign up my Business"}

So the category is being set but I’m not sure how to add this to my select in the view to use the category as the select value when a validation error occurs.

EDIT — adding controller code —-

class BusinessesController < ApplicationController

  def new
    @business = Business.new
    @business.build_user
  end

  def create
    @business = Business.new(params[:business])
     respond_to do |format|
      if @business.save
         cookies[:auth_token] = @business.user.auth_token
      format.html { redirect_to jobs_users_path, notice: 'Your business was successfully created.' }
   else
     format.html { render action: "new" }
   end
 end

end

Answer 1

I fixed this issue by making a few simple changes.

in my controller I added the following

def create
  #...
  category = (params[:business][:category_tokens])
  @category = category
  #...
end

Then used this in my view for the selected option.

<%= f.select(:category_tokens, Category.all.collect {|c| [ c.name, c.id ] }, { :include_blank => "Select Category", :selected => @category }}) %>