undefined method `has_many' for Formtastic

问题

I'm getting this error :

undefined method `has_many' for #<Formtastic::SemanticFormBuilder:0xb410d4c>

It work when I use it like this :

ActiveAdmin.register Ressource do
    form do |f|  
        f.inputs do
            f.input :offer_id, :as => :hidden
            f.input :name
            f.input :category, :include_blank => false, :collection => Category.order('place ASC').all, :member_label => :to_label
            f.input :description, :input_html => {:class => 'editor'}
            f.input :price
        end
        f.has_many :roles do |app_f|
            app_f.inputs do
                if not app_f.object.id.nil?
                    app_f.input :_destroy, :as => :boolean, :label => "Supprimer l'utilisateur du lot"
                end
                app_f.input :user, :member_label => :to_label, :label => 'Assigné le lot'
                app_f.input :name, :include_blank => false
            end
        end
        f.buttons
    end
end

But it doesn't work in a partial, i need to call the has_many method by a different way or something else ?

回答1:

ActiveAdmin extends formtastic with some useful helpers such as has_many (lib/active_admin/form_builder.rb in the activeadmin gem).

Unfortunately, these helpers are not available by default in your templates.

Here are two options:

If you don't need the extra has_many functionality (it looks like active_admin adds some javascript to make it easy to add a new record to the collection), then you can use stock formtastic. This example should work fine in the activeadmin file as well as in a partial:
```
ActiveAdmin.register Ressource do
  form do |f|  
    # ...
    f.inputs :for => :roles do |app_f|
      # ...
      app_f.input :name, :include_blank => false
    end
    f.buttons
  end
end 
```

Use the ActiveAdmin form builder explicitly:

<%= semantic_form_for [:admin, @resource], builder: ActiveAdmin::FormBuilder do |f| %>
  <!-- ... -->

  <%= f.has_many :teachers do |app_f| %>
    <%= app_f.inputs do %>
      <!-- ... -->
    <% end %>
  <% end %>

  <%= f.buttons %>
<% end %>

I hope this helps.

回答2:

There is a solution

form :html => {:multipart => true} do |f|
end

Or, if you want to use partial:

<%= active_admin_form_for [:admin, @resource] ,:html => {:multipart => true} do |f|%>
<% end %>

来源：https://stackoverflow.com/questions/10070779/undefined-method-has-many-for-formtastic

标签

ruby-on-rails-3

activeadmin

formtastic