Bldr - Rubyconf 2011 Lightning Talk

BLDRMinimalist JSON templating DSL

Alex Sharp@ajsharp

Friday, September 30, 2011

WHO AM I?

Alex Sharp (@ajsharp)

Ruby Engineer at Zaarly (zaarly.com)


WHAT IS ZAARLY?

Buyer-centric local commerce platform

Heavily api driven (iOS, Android, Web, HTML5 mobile)

API only speaks json


WHY BLDR?


LET ME COUNT THE REASONS

#as_json quickly gets...unwieldy

We need tight control over our json responses


SECURITY EXPLOIT

We were leaking information in our json documents we weren’t aware of

We didn’t understand #as_json was recursing through relationships and serializing them

Not good...


TECHCRUNCH STORY


BLDR

We wanted a simple, declarative DSL for defining JSON responses


BLDR

Simple, declarative DSL

Works with Sinatra

Rails 3 support nearly complete

Four DSL methods (object, collection, attribute, attributes)


SINATRA

get '/foo' do bar = 'baz' bldr :foo, :locals => {:bar => bar}end


SINATRA

# foo.bldrobject do attribute :foo, barend

# output{"foo": "baz"}


ATTRIBUTE LISTS

object :post => post do attributes :title, :bodyend

{ "post": { "title": "my title", "body": "..." }}


IMPLIED OBJECTS

object :post do attributes :title, :bodyend

{ "post": { "title": "my title", "body": "..." }}


DYNAMIC ATTRIBUTES

object :post do attribute :comment_count do |post| post.comments.count endend

{ "post": {"comment_count":1} }


OBJECT NESTINGobject :post => post do attributes :title, :body

object :author => post.author do attribute :last_name endend

{ "post": { "title": "my title", "body": "...", "author": {"last_name": "Doe"} }}


ATTRIBUTE ALIASESobject :post => post do attributes :title, :body

object :author => post.author do attribute :surname => :last_name endend

{ "post": { "title": "my title", "body": "...", "author": {"surname": "Doe"} }}


TOP-LEVEL COLLECTIONS

collection :posts => posts do attributes :title, :body attribute :comment_count { |post| post.comments.count }end

{ "posts": [ { "title": "my title", "comment_count": 2, }]}


NESTED COLLECTIONScollection :posts => posts do collection :comments => current_object.comments do attributes :body, :author, :email endend

{ "posts": [ { "comments": [ { "body": "...", "author_name": "Comment Troll", "email": "[email protected]" } ]}]}


OTHER FEATURES

Uses multi_json gem -- pick your encoding library

Bldr.handler


Bldr.handler BSON::ObjectId do |value| val.to_s # => "4e77a682364141ecf5000002"end


MORE INFO


MORE INFO

github.com/ajsharp/bldr

@ajsharp

[email protected]

zaarly.com / alexjsharp.com


mailto:[email protected]

mailto:[email protected]

Bldr - Rubyconf 2011 Lightning Talk

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Transcript of Bldr - Rubyconf 2011 Lightning Talk