# CRUD & REST

## Objectives

* Name the HTTP Verb associated with each CRUD function

## Review CRUD

Recall CRUD from the SQL database lessons. Most sites you interact with on the internet are CRUD sites. Almost everything you do on the web is a CRUD action. For example:

* ***Create*** a youtubeuser, a video, a comment, etc.
* ***Read*** comments, view videos, etc.
* ***Update*** your profile, edit a video title, etc.
* ***Delete*** a video, comment, or an entire channel!

[Formal definition on wiki](http://en.wikipedia.org/wiki/Create,_read,_update_and_delete)

## RESTful Routing

On the web the best practice for CRUD actions uses something called RESTful routing. The basic idea is your route (URL) should relate to the type of item you are interacting with, as well as the action you'll be performing to change/view the state of the item(s). Instead of relying exclusively on the URL to indicate what webpage you want to go to (and using just one method), RESTful routing is a combination of HTTP Verbs and URLs. RESTful stands for **RE**presentational **S**tate **T**ransfer. It is a set of principles that provide a way of mapping HTTP Verbs *(GET, POST, PUT, DELETE)* and CRUD actions together. When you click through a website by clicking on links, you're making a state transition which beings you to the next page (the next *state* of the application). A RESTful route incorporates:

* the *item or data* you're interacting with
* the *CRUD action* you're performing on that item or data

### Example: Dinosaurs

So if you were CRUDing a database of dinosaurs, the following routes would form a full set of CRUD RESTful routes. There are seven main RESTful routes:

| VERB   | URL                 | Action (CRUD)    | Description                                                             |
| ------ | ------------------- | ---------------- | ----------------------------------------------------------------------- |
| GET    | /dinosaurs          | Index (Read)     | lists all dinosaurs                                                     |
| GET    | /dinosaurs/new      | New (Read)       | shows a form to make a new dinosaur                                     |
| POST   | /dinosaurs          | Create (Create)  | creates an dinosaur with the POST payload data                          |
| GET    | /dinosaurs/:id      | Show (Read)      | list information about a specific dinosaur (i.e. /dinosaurs/1)          |
| GET    | /dinosaurs/edit/:id | Edit (Read)      | shows a form for editting a specific dinosaurs (i.e. /dinosaurs/edit/1) |
| PUT    | /dinosaurs/:id      | Update (Update)  | updates the data for a specific dinosaur (i.e. /dinosaurs/1)            |
| DELETE | /dinosaurs/:id      | Destroy (Delete) | deletes the dinosaur with the specified id (i.e. /dinosaurs/1)          |

*NOTE: With all of your POST, PUT, and DELETE routes, you'll want to add a redirect to a GET page*

[Read more on wiki](http://en.wikipedia.org/wiki/Representational_state_transfer)