form helper

form_tag:   和model無關

ex:

<% form_tag do %>

<p><label for=”login”>Login</label>

<%= text_field_tag  ‘login’ %></p>

<p><%= submit_tag ‘Log in’ %> </p>

<% end %>

1.如果form_tag後沒有接action，那麼action就是form目前所在的

  頁面對應到的method

2存取使用者輸入的資料，例如param, such as params[:login], log對應

  到text_filed_tag的值

ex:

<% form_tag  :action=>'play'  do %>

<p><label for=”login”>Login</label>

<%= text_field_tag  'car',  ‘login’ %></p>

<p><%= submit_tag ‘Log in’ %> </p>

<% end %>

1. text_field_tag後接的car是model name，login是car的attribute

   , the controller can access it using  params[:car][:login]

submit_tag 後接的字串是submit button上的文字

form_for : 和model有關

ex:

 <% form_for :person, @person, 

    :url => { :action => "create" } do |f| %>

      <%= f.text_field :first_name %>

      <%= f.text_field :last_name %>

      <%= submit_tag 'Create' %>

  <% end %>

對應的html

 <form action="/persons/create" method="post">

      <input id="person_first_name" name="person[first_name]" size="30" type="text" />

      <input id="person_last_name" name="person[last_name]" size="30" type="text" />

    <input name="commit" type="submit" value="Create" />

    </form>

存取使用者輸入的資料:

以上面為例子，Person.new(params[:person] )

ex:

<% form_for :rabbit ,  url=>{ :controller=>:rabbit, :action=>create},

      :html=> {:id=>’peter’ } do |t| %>

對應的html

<form action="/rabbit/create" id="peter" method="post">

text_field & text_field_tag

regular form helper is usually end with tag

model form helper is usually not end with tag 

ex:

text_field :customer, :name

create customer in the action of controller:

@customer = Customer.new(params[:customer])

text_field:

hidden_field:

password_field:

text_area:

radio_button(:variable, :attribute,  tag_value,  options):

check_box:

select:

selection list

ex: