Rails 3：Text_field_tag默認值如果參數[：something] .blank？

Question

如何將一個這樣做：

= f.input_field :age, 
        :collection => 18..60, 
        :id => 'age', 
        :selected => params[:age].blank? or "20" 

以上doesen't工作。如果無參數可用於該屬性，我希望能夠設置默認值。

任何智能的方法來做到這一點！

編輯1： 賽程表：

= simple_form_for :people, :url => request.fullpath, :method => :get, :html => { :class => 'form-search' } do |f| 
    #container_search_small.form-search 


     = f.input_field :age, 
         :collection => 18..60, 
         :id => 'age', 
         :selected => params[:people][:age_from] || "20" 



     = f.submit "Go »" 

Answer 1

您使用的是從對象你正在構建的形式以他們的價值觀助手。

所以在你的控制器中，你應該預設對象的值。

def some_action 
    @people = People.new 
    @people.age = params[:age] || 20 
end 

然後在窗體中，刪除:selected選項，它應該沒問題。確保你建立的表格爲@people：

= simple_form_for @people, :url => request.fullpath, :method => :get, :html => { :class => 'form-search' } do |f| 
    #container_search_small.form-search 


    = f.input_field :age, 
        :collection => 18..60, 
        :id => 'age' 



    = f.submit "Go »"