1. WSO2 Advantage Webinar
Extensible API Management
Nuwan Dias
Senior Software Engineer, WSO2
15/10/2013

2. About WSO2
• Providing the only complete open source componentized cloud
platform
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Dedicated to removing all the stumbling blocks to enterprise agility
Enabling you to focus on business logic and business value
• Recognized by leading analyst firms as visionaries and leaders
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Gartner cites WSO2 as visionaries in all 3 categories of
application infrastructure
Forrester places WSO2 in top 2 for API Management
• Global corporation with offices in USA, UK & Sri Lanka
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200+ employees and growing
• Business model of selling comprehensive support &
maintenance for our products

3. 150+ globally positioned support customers

4. Agenda
• Evolution of APIs
• Why should an API be extensible
• Designing an extensible API
• Real World Use Cases

5. Evolution of APIs
• Companies used phone, mail, advertising to reach customers.
• Then came websites, where companies advertised themselves.
• WAP versions of websites....... very limited success.
• Mobile web browsers did not live up to its potential
• Companies started building their own Apps (Applications)
• ** If you could reach your consumers through your Apps, how
much further can you reach through Apps developed by a
developer community.

6. What is Extensibility ?
• Hooks or plug-points to insert one's own programming routines
to the incoming and/or outgoing message flows.

7. Why should an API be extensible ?
• Helps you to reach the long tail...
• Longer lifetime of the API
• Enables your API to connect to other libraries or entire
Applications
• Helps you get over mistakes.

8. Designing an Extensible API.
• Always return a consistent wrapper Object
– Ex: A successful response for a database query.
<product>
<name>Swiss Watch</name>
<category>Watches</category>
<color>Black</color>
</product>
– When no data found
<error>No Data Found</error>
– A better approach would be
<response>
<errorCode>0</errorCode>
<product>
<name>Swiss Watch</name>
<category>Watches</category>
<color>Black</color>
</product>
</response>

9. Designing an Extensible API.....
• Support Multiple Formats
– Ex: XML/JSON
• Keep parameter count consistent
• Support API Versioning
• Keep response key types consistent
– Ex: If you have an API that returns <bookid type=”integer”>12831</bookid>
– Do not have another api which returns <bookid>
• Structure the API URL
– Ex: http://myproducts.com/{api}/{resource}
http://myproducts.com/products/product/1
http://myproducts.com/products/category/electronics

10. Designing an Extensible API.....
• Use OAuth
• Document your API religiously

11. Real World Use Cases
• Conversion from XML to JSON

12. Real World Use Cases
• Location Based Dispatching

13. Questions ?

14. Engage with WSO2
• Helping you get the most out of your deployments
• From project evaluation and inception to development
and going into production, WSO2 is your partner in
ensuring 100% project success

15. Engage with WSO2