ruby select/select_tag

select_tag:
 
<%= select_tag("article[type_id]),options_for_select([[選択してください]]]++ArticleType.all.map{|t|[t.name,t.id]},:selected=>record.type_id)))%>
 
selectの:selected値はvaluesのタイプと一致します.
<%= select_tag("article[type_id]),[[選択してください],nil]++ArticleType.all.map{|t|[t.name,t.id]},:selected=>record.type_id)%>
 
あるいはhelp層に書く(より効果的)
view
<%=ongoing_material_select 'material[][material_id]',f.material.id %>
 
help
 
def ongoing_provider_select name,selected,js_function=nil    select_tag name,                options_from_collection_for_select(Provider.ongoing_provider, "id", "name", selected),                {:include_blank=>'None', "onchange"=>"javascript:#{js_function}"} end
 
select :
 

 select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, { :include_blank => true })

 <select name="post[person_id]">
    <option value=""></option>
    <option value="1" selected="selected">David</option>
    <option value="2">Sam</option>
    <option value="3">Tobias</option>
  </select>

 
 
 
prototype.js
 
 
 

<%= text_field_tag  'product[no]',{}, :onchange => remote_function(:update => "no_result",  
					       :method => "get",  
					       :with => "'no=' + value",  
					       :url => { :controller => :product, :action => :is_show})   
					       %>
						  <span id="no_result"></span>

 
 

<%= select :obj, :att,  @items, {}, :onchange => remote_function(:update => "sub_items",  
       :method => "get",  
       :with => "'item=' + value",  
       :url => { :controller => :home, :action => :get_sub_items})   
       %> 

 
 

<%=select_tag ( 'product[style_id]',options_for_select([["   ",0]]+Style.find(:all).map{|t| [t.name, t.id]}), 
																:onchange => remote_function(:update => "sub_items",  
														       :method => "get",  
														       :with => "'style_id=' + value",  
														       :url => { :controller => :product, :action => :get_pic_look})   )%>

 
 

<%=link_to_remote '  ',:update=>'mpart_table',
								  :url=>{:controler=>:product,:action=>:del_row_mpart,:id=>mpart.id},
                                  :confirm=>"             ？"%>