form select box from association

rubyonrails-talk
1

Hello there,

I have the following models

class Bibliography < ActiveRecord::Base   has_and_belongs_to_many :gthemes, :join_table => "gthemes_bibliographies" end

class Gtheme < ActiveRecord::Base   has_and_belongs_to_many :bibliographies, :join_table => "gthemes_bibliographies" end

I want to include in the bibliography edit page a select box with all the gthemes and i want the members of @bibliography.gthemes to be marked as selected

I 'm using this in bibliography/_form.rhtml:

<%= select('bibliography', 'gthemes' , Gtheme.find(:all).collect{ |gt| [ gt.name, gt.id]}, {}, {:multiple => true}) %>

but it doesn't mark the current gthemes as selected, any ideas?

Thanks in advance, Christos

2

I also tried using the form_for helper but the problem still exists

<% form_for :bibliography, @bibliography, :url => { :action => "update" } do |f| %>   Bgthemes: <%= f.select :gthemes, Gtheme.find(:all).collect {|c| [c.name, c.id]}, {}, {:multiple => true} %>   <%= submit_tag 'Save changes' %> <% end %>

3

For the record, I didn't manage to find a "magic way" to do it, but this is a nice and working solution:

<%= select_tag 'gthemes',   options_from_collection_for_select(@gthemes, 'id', 'name', @bibliography.gtheme_ids ),   {:multiple => true, :class => "wide"} %>

4

@gthemes = Gtheme.find(:all)