It is for Rails scaffold, but it more or less describes how things are done in Rails.
First, there is nothing yet.
For the Create in CRUD:
We need a form to create a record (unless somebody directly use a program to send an HTTP request to our server). The form is generated by:
www.mysite.com/foos/new
the above generates a form in HTML. It is a GET /foos/new
nothing special there.
Note that for this form, when a user enters all the details, and click the "Create" button, it POST to /foos/ that is, it POST to www.mysite.com/foos/
the Rails's FoosController#create action will handle it.
the HTTP request is:
POST http://www.mysite.com/foos/ HTTP/1.1
Near the end of this create action, it redirects to http://www.mysite.com/foos/1
This is a GET /foos/1
and it is for the Retrieval in CRUD.
It is handled by FoosController#show action
GET http://www.mysite.com/foos/1 HTTP/1.1
For the Update in CRUD:
To edit something, we need a form, (unless using a program to directly submit the changes)
http://www.mysite.com/foos/1/edit
it is just a GET, handled by FoosController#edit action
when user clicks Update button, it sends
POST http://www.mysite.com/foos/1 HTTP/1.1
The Rails development log says it is a PUT, but Fiddler on Windows shows that it is a POST
the POST variables are
_method=put&authenticity_token=9dMLgD4E6liD2%2Bo7dOVsBJ7B3Vdy9e2v%2F5bE36YgpYE%3D&foo%5Bs%5D=hi&foo%5Bi%5D=333&foo%5Bf%5D=2.0&foo%5Bnote%5D=wah&commit=Update
it is handled by FoosController#update action.
After the update, it redirects back to
http://www.mysite.com/foos/1
to show you the record again.
Now the Destroy in CRUD:
The Destroy link is in /foos which shows all the records for foo
Click on Destroy, and it does a POST http://www.mysite.com/foos/1 HTTP/1.1
with POST variables
_method=delete&authenticity_token=9dMLgD4E6liD2%2Bo7dOVsBJ7B3Vdy9e2v%2F5bE36YgpYE%3D
so it is not a DELETE. It is handled by FoosController#destroy
To summarize:
| Which of CRUD | to prepare the form | controller and action to prepare the form | when the real action of CRUD is happening | controller and action |
| C | GET /foos/new | FoosController#new | POST /foos/ | FoosController#create |
| R | GET /foos/1 | FoosController#show | ||
| U | GET /foos/edit | FoosController#edit | POST /foos/1 _method=put | FoosController#update |
| D | GET /foos/ | FoosController#index | POST /foos/1 _method=delete | FoosController#destroy |
This is tested again using Ruby 1.9.2 and Rails 3.0.5, and the Update and Delete are done the same way: using a POST, with _method=put or _method=delete.
