I got this error when I have to upgrade one old project from rails 1.2.5 to rails 2.1 (the problem is not in rails)

ActionController::MethodNotAllowed

Only get, head, post, put, and delete requests are allowed.

The exception:

ActionController::MethodNotAllowed (Only get, head, post, put, and delete requests are allowed.):
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_controller/routing/recognition_optimisation.rb:65:in `recognize_path'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_controller/routing/route_set.rb:384:in `recognize'

I got this error only when I access URL’s with param like

http://127.0.0.1:3000/dod/images/show_big_image/1639

I found that the problem was in the :id because without the :id the method was called correctly

This means that there is something with the routes.

Not working routes.rb: ….

  map.connect '', :controller => 'auth'

  # Install the default route as the lowest priority.
  map.connect ':controller/:action/:id'
  map.connect ':controller/:action/:sort_key/:sort_order'

it will work if you swap the last two lines….

  map.connect '', :controller => 'auth'

  # Install the default route as the lowest priority.
  map.connect ':controller/:action/:sort_key/:sort_order'
  map.connect ':controller/:action/:id'

It seems that it does reading the comments in the routes.rb is usefull. There is written:

# Install the default route as the lowest priority.

This error also occurs if you haven't restart your webserver. I know that there is no need to restart it but its true, try restarting and check.

It is very easy to handle ajax pagination as described on this post here.

I want to give one full example.

Here is how my form looks:

<% form_remote_tag :url => {
                      :action => 'handle_urls',
                      :script_id => @script,
                      :page => params[:page],
                    },
  :html => {:id => 'f'},
  :update => "filtered_articles_pane" do %>

Here is how my will_paginate helper looks:

<%= will_paginate @filtered_urls,
  :renderer => 'RemoteLinkRenderer',
  :remote => { :with => "'script_id=#{@script.id}&approved_flag='+$(\'approved_flag\')",
  :update => 'filtered_articles_pane'} %>

I have used the improved version of the will_paginate:

# Use it like so…
# will_paginate :collection, :remote => {:with => 'value', :update => 'some_div'} 

class RemoteLinkRenderer < WillPaginate::LinkRenderer
  def initialize(collection, options, template)
    @remote = options.delete(:remote)
    super
  end

  def page_link_or_span(page, span_class = 'current', text = nil)
    text ||= page.to_s
    if page and page != current_page
      @template.link_to_remote(text, {:url => url_options(page), :method => :get}.merge(@remote))
    else
      @template.content_tag :span, text, :class => span_class
    end
  end
end

Update for will_paginate 2.3.x

# app/helpers/remote_link_renderer.rb

class RemoteLinkRenderer < WillPaginate::LinkRenderer
  def prepare(collection, options, template)
    @remote = options.delete(:remote) || {}
    super
  end

protected
  def page_link(page, text, attributes = {})
    @template.link_to_remote(text, {:url => url_for(page), :method => :get}.merge(@remote))
  end
end

The most valuable usage for scaffolding is when you use it in the administration part of the site. The administration is usually separated in separate module/folder.

The new rails scaffolding is not good because:

• It is time taking to setup nested scaffold
• I have tons of uselss source code in the scaffolding like respond_to ... that is usable very rare or never.
• The HTML that is generated is ugly and not usable for CSS skin
• Not using the nice ruby style iterations .each instead of for's
• Code repetition, the “new” and the “edit” views has the same form elements
• Not easy to find documentation

I find Akita article for scaffolding. It is is great that he has covered some real cases. It is a lot of reading and I must read/copy/paste every time I need to make a scaffold. Here is step by step on making scaffold for administration.

• ruby script/generate scaffold admin::BadArticle NOT PLURAL!
  • user:references
  • description:text,string
  • fixed:boolean
  • timestamps are automaticaly added
• Add in routes.rb

  • map.namespace :admin do |admin|
      admin.resources :bad_articles
    end

• Model
  • Rename admin::BadArticles -> BadArticle,
  • move it to the model directory
  • rename the file
• Fix the migration file:
  • remove the prefix from the migration class,
  • remove the prefix from table name
  • rename the file
• URL references
  • admin_bad_articles_url
  • redirect_to([:admin, bad_article])
• Controller
  • rename all Admin::BadArticles -> BadArticle except in the controller name
  • Probably you will want to make your scaffold inhired your base admin controller

  • def create
       ...
       format.html { redirect_to([:admin, @filtered_url]) }
       ...
    end

  • def update
        ...
            format.html { redirect_to([:admin, @filtered_url]) }
        ...
    end

  • class Admin::BadArticlesController < ApplicationController

    class Admin::BadArticlesController < Admin::AuthController
      layout 'admin'
     (in case that you don't have it in the base controller)

  • def index
      @admin_bad_articles = BadArticle.find(:all)
      respond_to do |format|
        format.html # index.html.erb
        format.xml  { render :xml => @admin_bad_articles }
      end
    end

• Index.rhtml.erb

  • <td><%= link_to 'Edit', edit_admin_bad_article_path(bad_articles) %></td>

  • <%= link_to 'New bad_articles', new_admin_bad_articles_path %>

• edit.rhtm

  • <%= link_to 'Show', @bad_article %> |
    <%= link_to 'Back',bad_articles_path %><%= link_to 'Show', [:admin, @bad_article_url] %> |
    <%= link_to 'Back', admin_bad_articles_path %>

• show.html.erb

  • <%= link_to 'Edit', edit_filtered_url_path(@filtered_url) %> |
    <%= link_to 'Back', filtered_urls_path %>

• new.rhtml

  • <% form_for(@bad_article) do |f| %><% form_for([:admin, @bad_article]) do |f| %>

  • <%= link_to 'Back', bad_articles_path %><%= link_to 'Back', admin_bad_articles_path %>

Traps:

The order of the routes in routes.rb does matter! In order to make the REST work you must have this block at the bottom of your routes.rb like this:

map.namespace :admin do |admin|
  admin.resources :bad_articles
end

# Install the default route as the lowest priority.
map.connect ':controller/:action/:id.:format'
map.connect ':controller/:action/:id'


Remove simply_helpful plugin if you get the error:

undefined method `new_record?' for #Array:0x532a3e8

Debuging tools:

rake routes

Tips:

How to add custom actions to the REST

map.namespace :admin do |admin|
  admin..esources :bad_articles, :member => {:toggle => :get}
  admin.resources :orders, :member => { :resend => :post }
  admin.resources :users,  :collection => { :filter => :any }
end

Then in the controller:

def toggle
  @bad_article = BadArticle.find(params[:id])
  @bad_article.fixed = ! @bad_article.fixed
  @bad_article.save
  redirect_to  admin_bad_articles_url
end

And in the view:

<%= toggle_admin_bad_article_url(filtered_url) %>

More reading here

Resources:

• restful_rails_en
• Akita article
• http://frozenplague.net/2008/01/06/restful-routing-an-overview/