Ruby form的两种写法

下面介绍Ruby form的两种写法。
Ruby form写法一：使用form_for
< % form_for :order, :url => { :action => :save_order } do |form| %>   < p>    < %= label :order, :name, "Name:" %>    < %= form.text_field :name, :size => 40 %>     < /p>   < p>    < %= label :order, :address, "Address:" %>    < %= form.text_area :address, :rows => 3, :cols => 40 %>   < /p>   < p>    < %= label :order, :email, "E-Mail:" %>    < %= form.text_field :email, :size => 40 %>   < /p>   < %= submit_tag "Place Order" , :class => "submit" %> < % end %> 
来看看解释
引用
There are two interesting things in this code. First, the form_for helper on line 1 sets up a standard HTML form. But it does more. The first parameter, : order,tells the method that it’s dealing with an object in an instance variable named @order. The helper uses this information when naming fields and when arranging for the field values to be passed back to the controller.
The :url parameter tells the helper what to do when the user hits the submit button. In this case, we’ll generate an HTTP POST request that’ll end up getting handled by the save_order action in the controller.
而每个form的helper方法，如form.text_area,form_text_field,后面跟的符号，如:name,:address,:email，等都是这个model的属性。form_f