rails: "unknown action" message when action is clearly specified - ruby-on-rails

Question

I had hard time to figure out why I've been getting "unknown action" error message when I was do some editing:
Unknown action
No action responded to 11. Actions: bin, create, destroy, edit, index, new, observe_new, show, tag, update, and vote
you can see that Rails did mention each action in the above list - update. And in my form, I did specify action = "update".
I wonder if some friends could kindly help me with the missing links...
here is the code:
edit.rhtml
<h1>Editing tip</h1>
<% form_tag :action => 'update', :id => #tip do %>
<%= render :partial => 'form' %>
<p>
<%= submit_tag_or_cancel 'Save Changes' %>
</p>
<% end %>
_form.rhtml
<%= error_messages_for :tip %>
<p><label>Title<br/>
<%= text_field :tip, :title %></label></p>
<p><label>Categories<br/>
<%= select_tag('categories[]', options_for_select(Category.find(:all).collect {|c| [c.name, c.id] }, #tip.category_ids), :multiple => true ) %></label></p>
<p><label>Abstract:<br/>
<%= text_field_with_auto_complete :tip, :abstract %></label></p>
<p><label>Name: <br/>
<%= text_field :tip, :name %></label></p>
<p><label>Link: <br/>
<%= text_field :tip, :link %></label></p>
<p><label>Content<br/>
<%= text_area :tip, :content, :rows => 5 %></label></p>
<p><label>Tags <span>(space separated)</span><br/>
<%= text_field_tag 'tags', #tip.tag_list, :size => 40 %></label></p>
class TipsController < ApplicationController
before_filter :authenticate, :except => %w(index show)
# GET /tips
# GET /tips.xml
def index
#tips = Tip.all
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #tips }
end
end
# GET /tips/1
# GET /tips/1.xml
def show
#tip = Tip.find_by_permalink(params[:permalink])
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => #tip }
end
end
# GET /tips/new
# GET /tips/new.xml
def new
#tip = session[:tip_draft] || current_user.tips.build
end
def create
#tip = current_user.tips.build(params[:tip])
#tipMail=params[:email]
#if tipMail
# TipMailer.deliver_email_friend(params[:email], params[:name], tip)
# flash[:notice] = 'Your friend has been notified about this tip'
#end
#tip = current_user.tips.build(params[:tip])
#tip.categories << Category.find(params[:categories]) unless params[:categories].blank?
#tip.tag_with(params[:tags]) if params[:tags]
if #tip.save
flash[:notice] = 'Tip was successfully created.'
session[:tip_draft] = nil
redirect_to :action => 'index'
else
render :action => 'new'
end
end
def edit
#tip = Tip.find(params[:id])
end
def update
#tip = Tip.find(params[:id])
respond_to do |format|
if #tip.update_attributes(params[:tip])
flash[:notice] = 'Tip was successfully updated.'
format.html { redirect_to(#tip) }
format.xml { head :ok }
else
format.html { render :action => "edit" }
format.xml { render :xml => #tip.errors, :status => :unprocessable_entity }
end
end
end
def destroy
#tip = Tip.find(params[:id])
#tip.destroy
respond_to do |format|
format.html { redirect_to(tips_url) }
format.xml { head :ok }
end
end
def observe_new
session[:tip_draft] = current_user.tips.build(params[:tip])
render :nothing => true
end
end

Answer 1

the quick answer is that form_tag doesn't support :action as an option, you want to be passing a string as a path in. A slightly longer answer is you shouldn't be using form_tag anyways for a model edit form, you should be using form_for.
what rails are you using? .rhtml is pretty old, rails generators should be giving you .html.erb files. if it is something even remotely recent, you should be able to use
<% form_for #tip do |f| %>
<%= f.label :title, 'Title' %><br />
<%= f.text_field %>
... etc
<% end %>