Designing RESTful Rails Applications

8/14/2019 Designing RESTful Rails Applications

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DesigningRESTful

Rails

A licationsObie Fernandez

Prepared exclusively for QCon 2007


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Topics

What is REST?

REST in Rails

Routing and CRUD

Resources and Representations


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Presentation Goals

Its a big topic, so focusing on the most essential stuff

Convince you that REST is worth investigating further

Keep emphasis on practical advice and gotchas

Dont put you, the audience to sleep


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What is REST?


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Roy Fielding

before_destroy

DELETE operation

after_destroy


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REST is an architecturalstyle manifested in the web


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The REST

constraints includeUse of a client-server architectureStateless communication

Explicit signaling of responsecacheability


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REST is designed to help

you provide services usingthe native idioms and

constructs of HTTP


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Just use what HTTPalready gives you.


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One of the payoffs of REST is

that it scales relatively well for

big systems, like the web.


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REST in Railsview helper methods and enhancements tothe routing system


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Benefits of RESTful Rails

Convenience and

automatic best practices

for you

A REST interface to your

applications services, for

everyone else


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Much Rails practice is

noncompliant with theprecepts of REST

from the beginning.


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Routing and CRUD


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REST in Rails involves

standardization of actionnames.


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map.resources :auctions


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Resources and

RepresentationsREST characterizes communication between

system components as a series of requests to

which the responses are representations ofresources.


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What you actually do get hold

of is never the resource itself,but a representation of it.


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OpinionatedREST Support


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map.auction auctions/:id,:controller => auction,:action => show


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auction_delete_path


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auction_delete_path

auction_create_path


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auction_create_path


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auction_path


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auction_path

auctions_path


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http://localhost:3000/auctionshttp://localhost:3000/auctions


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The HTTP Verb


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/auctions submitted in a GET request!

/auctions submitted in a POST request!


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map.resources :auctions


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The Standard RESTfulController Actions


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index

new

create

showedit

updatedestroy


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A lot of work is done for you

and the action names arenicely CRUD-like.


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Rules for Request Methods

The default is GET

In a form_tag or form_for call, the POST methodwill be used automatically

If necessary, you can explicitly specify a request

method along with the URL generated by the namedroute (PUT and DELETE operations)


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auction_path(auction),:method => :delete %>


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auction_path(@auction),:html => { :method => :put } do |f| %>


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The PUT and DELETE hack


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The Special Pairs


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create and update

operations involve twoactions

The action that results in thedisplay of the form

The action that processes the forminput when the form is created


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Singular Named Routes


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map.resource :address_book


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Nested Resources


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/auctions/3/bids/5


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/bids/5


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params[:auction_id]

/auctions/3/bids/5


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map.resources :auctionsdo |auction|

auction.resources :bidsend


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/auctions/3/bids


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/auctions/3/bids

params[:auction_id] # in your controller


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You can nest to any depth.Each level of nesting adds one to the

number of arguments you have to supply to

the nested routes.


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map.resources :my_auctions, :controller => :auctionsdo |auction|auction.resources :my_bids, :controller => :bids

end


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Restful Route Customizations


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map.resources :auctionsdo |auction|auction.resources :bids

end


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map.resources :auctionsdo |auction|auction.resources :bids

end

/auctions/3/bids/5/retract

retract_bid_url(auction, bid)


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map.resources :auctionsdo |auction|auction.resources :bids,

:member => { :retract => :get }

end


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map.resources :auctionsdo |auction|auction.resources :bids,

:member => { :retract => :get }

end


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Different Representations ofResources


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The responds_to method

http://example.com/auctions.xml
http://example.com/auctions.xmlhttp://example.com/auctions.xmlhttp://example.com/auctions.xmlhttp://example.com/auctions.xml


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defindex@auctions = Auction.find(:all)respond_todo |format|

format.htmlformat.xml {

render :xml => @auctions.to_xml}

endend

http://example.com/auctions.xml
http://example.com/auctions.xmlhttp://example.com/auctions.xmlhttp://example.com/auctions.xmlhttp://example.com/auctions.xmlhttp://example.com/auctions.xml


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XML version of this auction


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Discussion and Q/A


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My Book is

Shipping!


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My Blog

If you are a Rails developer and you

liked this talk, please recommend

me on workingwithrails.com
http://jroller.com/obiehttp://jroller.com/obie

Documents

Designing RESTful Rails Applications