params[:fu] #1 ) Wrap all relevant attributes in a single params key.

This is the simplest form of using form_for and params:

<% form_for @reader do |f| %>
  <%= f.text_field :name %>
  <%= f.text_field :birth_place %>

  <%= f.submit 'Create' %>
<% end %>

Processing ReadersController#create (for 127.0.0.1 at 2008-01-14 21:12:56) [POST]
Parameters: { "commit"             => "Create",
              "reader"             => { "name" => "stephen chu", "birth_place" => "hong kong" },
              "authenticity_token" => "238ba79b8282882ba01d840352616c2cc79280f0",
              "action"             => "create",
              "controller"         => "readers"}

def create
  @reader = Reader.create! params[:reader]
end

By doing this, you eliminate the need to explicitly spell out each parameters posted, like the ugly Reader.new :name => params[:name], :birth_place => params[:birth_place].

Notice, Active Record is extremely hash-happy. Let's take a few examples and see how it is so hash-hungry (or rather, hash-happy).

@reader = Reader.new params[:reader]  # => { 'first_name' => 'stephen', 'last_name' => 'chu' }

@readers = Reader.find(:all, :conditions => params[:search])  # => { 'name' => 'chu' }

@reader.attributes = params[:reader]  # => { 'first_name' => 'martin', 'last_name' => 'fowler' }

@reader.update_attributes(params[:reader])  # => { 'birth_place' => 'hong kong' }

Notice the find with condition one. No one says I cannot have a hash or form_for that must map to a database table!

All of the above will work in just one line of code, and I am sure you can find more examples as well. Remember, hashes are one of the most underrated Rails toolset to reduce code you need to write. Stay tuned on how we can optimize the use of these AR one-liners.

(back to the TOC of the params[:fu] series)