Ruby on Rails语法混淆

Question

I am starting to learn Rails and I am confused as heck.

<%= form_for :story, url:'create' do |f| %>
<p>
    <%= f.label :title %>
</p>

<p>
    <%= f.submit %>
</p>

<% end %>

So, the way I understand is that form_for is a method which takes a model. I pass in the :story. Even if I replace the :story with :post it will work as expected.

The url is set as url: instead of :url (Why colon after works and colon before does not)

The following does not work:

<%= form_for @story, {url => "create"} do |f| %>

Answer 1

This has to do with the initialize method of the ActionView::FormHelper

:story is a symbol . In ruby, symbols which are essentially constants are expressed with a colon before the string.

which creates

<form action="/story" method="post">

url: 'create' is a ruby hash which uses symbols as keys and can be written as

{url: create} or { :url => "create"}