Designing Evolvable Web APIs with ASP.NET

1. The Internet, the World Wide Web, and HTTP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Web Architecture 2
Resource 3
URI 4
Cool URIs 5
Representation 5
Media Type 5
HTTP 8
Moving Beyond HTTP 1.1 8
HTTP Message Exchange 8
Intermediaries 10
Types of Intermediaries 11
HTTP Methods 12
Headers 15
HTTP Status Codes 16
Content Negotiation 17
Caching 17
Authentication 20
Authentication Schemes 21
Additional Authentication Schemes 22
Conclusion 22
2. Web APIs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
What Is a Web API? 23
What About SOAP Web Services? 23
Origins of Web APIs 24

The Web API Revolution Begins 24
Paying Attention to the Web 24
Guidelines for Web APIs 25
Domain-Specific Media Types 25
Media Type Profiles 26
Multiple Representations 27
API Styles 29
The Richardson Maturity Model 29
RPC (RMM Level 0) 30
Resources (RMM Level 1) 31
HTTP VERBS (RMM Level 2) 33
Crossing the Chasm Toward Resource-Centric APIs 36
Hypermedia (RMM Level 3) 36
REST 41
REST Constraints 41
Conclusion 43
3. ASP.NET Web API 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Core Scenarios 45
First-Class HTTP Programming 46
Symmetric Client and Server Programming Experience 48
Flexible Support for Different Formats 48
No More “Coding with Angle Brackets” 48
Unit Testability 49
Multiple Hosting Options 50
Getting Started with ASP.NET Web API 50
Exploring a New Web API Project 54
WebApiConfig 54
ValuesController 56
“Hello Web API!” 58
Creating the Service 58
The Client 65
The Host 65
Conclusion 66
4. Processing Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
The Hosting Layer 70
Message Handler Pipeline 71
Route Dispatching 73
Controller Handling 75
The ApiController Base Class 75