Traditional .NET development frameworks tend to be big, and cover all possible eventualities, and for many projects this is A Good Thing. But for just as many, if not more, projects, a full one size fits all service solution like WCF is just overkill, and adds unnecessary complexity. This is A Bad Thing. In this talk, I'll go over a lightweight, low-ceremony approach to creating a public APIs for the web in .NET. I will show how to use REST and the Nancy framework to create service applications with less code, less cruft and fewer maintenance headaches. We'll follow the super-duper happy path of Nancy, .NET's answer to Ruby's ultra-lightweight Sinatra framework, to create RESTfull API's that takes full advantage of HTTP and it's ubiquity to make building client applications equally enjoyable.

1. The Lightweight Approach to Building
Web Based APIs with .NET
Christian Horsdal
Independent Consultant
@chr_horsdal
http://horsdal.blogspot.com

2. Agenda
Who Am I?
What is “lightweight”
RestBucks
REST
Nancy

3. 3
Who Am I?
Independent consultant
Husband and Father
Some who enjoys
Clean code
TDD’ing
When my soccer team wins
Simplicity
Whisky

4. What is lightweight?
4

5. 5
What is lightweight?
Low ceremony
Low cruft
Conventions

6. 6
What is lightweight?
Open
Agile
Inexpensive

7. RestBucks
7

8. RestBucks
8

9. 9
REST

10. 10
Richardsons Maturity Model
Level 3: Hypermedia
Level 2: HTTP Verbs
Level 1: Resources
Level 0: POX-RPC

11. 11
REST - Resources
The basic building blocks of a web API
Anything with a URI
http://restbucks.com/menu/
http://restbucks.com/orders/
http://restbucks.com/order/42/
http://restbucks.com/order/42/payment/

12. 12
REST - Representations
GET http://restbucks.com/order/19202048/ HTTP/1.1
Accept: application/vnd.restbucks+xml
<?xml version="1.0"?>
<order xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="h
<links>
<link uri="http://restbucks.com/order/19202048" rel="http://restbucks
<link uri="http://restbucks.com/order/19202048" rel="http://restbucks
<link uri="http://restbucks.com/order/19202048" rel="http://restbucks
<link uri="http://restbucks.com/order/19202048/payment" rel="http://r
</links>
<location>inShop</location>
<cost>7.60000</cost>
<items>
<item>
<name>Latte</name>
<quantity>1</quantity>
<milk>skim</milk>

13. 13
REST - Representations
GET http://restbucks.com/order/19202048/ HTTP/1.1
Accept: application/vnd.restbucks+json
{
"Location":inShop,
"Cost":7.60000,
"Items":[
{
"Name":"Latte",
"Quantity":1,
"Preferences":{
"milk":"skim",
"size":"large"
}
}
],
"Status":1,
"Links":[

14. 14
REST - verbs
GET
POST
PUT
DELETE
HEAD
OPTIONS
PATCH

15. 15

16. 16
Why Nancy?
“Close” to http
Very, very readable code
Very explicit routing
Automatic content negotiation
Embraces modularity
Embraces IoC/DI
Embraces testing
Runs anywhere

17. Nancy Basics
public class MainModule : NancyModule
{
public MainModule()
{
Get["/"] = _ => "Hello from root";
}
}
public class SubModule : NancyModule
{
public SubModule() : base("subpath")
{
Get["/"] = _ => "Hello from subpath";
}
}

18. Nancy Basics
Defines which verbs you accepts
public class MainModule : NancyModule
{
public MainModule()
{
Get["/"] = _ => "Hello from root";
Post["/"] = _ => DoPost(Request.Form.my_value);
Delete["/{id}"] = p => Delete(p.id);
Put["/"] = _ => DoPut(Request.Body);
Patch["/"] = _ => DoPatch(Request.Body);
}
}
HEAD and OPTIONS and automatic

19. Restbuck on Nancy 19
Place an Order

20. RestBucks on Nancy 20
View/Cancel/Update

21. RestBucks on Nancy 21
Pay an Order

22. RestBucks on Nancy 22
XML, JSON or YAML

23. RestBucks on Nancy 23
Conditional Gets

24. 26
Nancy.Testing
Test through the whole Nancy pipeline
Take advantage of IoC/DI
…Or not

25. 27
Why Nancy?
“Close” to http
Very, very readable code
Very explicit routing
Automatic content negotiation
Embraces modularity
Embraces IoC/DI
Embraces testing
Runs anywhere

26. 28
Why REST + Nancy
Lightweight
Low ceremony
Low cruft
Follows conventions
Open
Agile

27. 29
More …
RestBucks on Nancy: http://github.com/horsdal/Restbucks-on-Nancy
Rest in Practice: http://restinpractice.com/book.html
Nancy: www.nancyfx.org
Me:
Twitter: @chr_horsdal
Blog: horsdal.blogspot.com
Email: c.horsdal@gmail.com