This talk is split in three parts. In the first part, I talk about web APIs, then I focus on publishing ASP.NET Web APIs on Azure using Azure App Service and, finally, I explore how we can consume those APIs.

1. Publishing & Consuming APIs on Azure – Paris Polyzos – Stoiximan 30/09/2017 © by kariera.gr
Paris Polyzos
Senior Software Engineer @ Stoiximan
Publishing & Consuming
Web APIs

2. Agenda
© 2017 by kariera.gr 2
APIs
Publish To Azure
Consume APIs
Translator Text API Text Analytics API

3. 3
@ppolyzos
Paris Polyzos
Senior Software Engineer
@ Stoiximan
github.com/ppolyzos
ppolyzos.com
AzureHeads.gr
© 2017 by kariera.gr

4. Part I
Web APIs Theory

5. A set of set of routines, protocols, and tools for building software and
applications.
In simple words:
API is some kind of interface which has a set of functions that allow
programmers to access specific features or data of an application,
operating system or other services.
What is API?
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6. An API over the web which can be accessed using
HTTP protocol
What is Web API?
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7. What is ASP.NET Web API?
ASP.NET Web API is a
framework that makes it
easy to build HTTP services
that reach a broad range of
clients, including browsers
and mobile devices.
ASP.NET Web API is an
ideal platform for building
RESTful applications on the
.NET Framework.
© 2017 by kariera.gr 7

8. What is JSON?
• JSON (JavaScript Object Notation)
Is a lightweight data-
interchangeable format
• Easy for humans to read and write
• Easy for machines to parse and
generate
• Two Structured Types: objects and
arrays
An object is an unordered collection
of zero or more name/value pairs
© 2017 by kariera.gr 8

9. HTTP Verbs
Methods to indicate the desired action to be performed for a given
resource.
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Http Verbs CRUD Description
GET Read Retrieve Data
POST Create Causing a change in state or side
effects on the server
PUT Update / Replace Replaces all current representations
of the target resource with the
request payload.
PATCH Update / Modify Apply partial modifications to a
resource
DELETE Delete Deletes the specified resource

10. HTTP Status Codes
HTTP defines forty standard status codes that can be used to convey
the results of a client’s request. The status codes are divided into the
five categories presented below.
© 2017 by kariera.gr
Category Description
1xx: Informational Communicates transfer protocol-level information.
2xx: Success Indicates that the client’s request was accepted
successfully.
3xx: Redirection Indicates that the client must take some additional
action in order to complete their request.
4xx: Client Error This category of error status codes points the finger at
clients.
5xx: Server Error The server takes responsibility for these error status
codes.
10

11. Part II
Publishing APIs

12. Part III
Consuming Web APIs

13. THANK YOU

14. What is Rest?
Guiding Principles of REST
• Client – Server
Separate UI from the data storage
• Stateless
Each request from client to server must
contain all of the information necessary to
understand the request.
• Cacheable
Apply Cache Constraints
• Uniform interface
• Layered System
• Code on demand (optional)
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“REST is acronym for REpresentational State Transfer”
Resource
The key abstraction of information in REST
is a resource.
Any information that can be named can be a
resource:
• a document or image,
• a temporal service,
• a collection of other resources,
• a non-virtual object (e.g. a person), and so
on