1. GAININGTHE KNOWLEDGEOF THE OPEN DATA PROTOCOL (ODATA) ChrisWoodruff

2. WHO I AM? ChrisWoodruff MVP,Visual C# Director at Perficient Co-host of Deep Fried Bytes Podcast @cwoodruff / cwoodruff@live.com Skype: cwoodruff 3. YOUWILL LEARN: Understand the background of OData Have an understanding of the OData protocol How to produce an OData feed using WCF Data Services How to produce an OData feed using ASP.NET Web API How to consume an OData feed using LINQ 4. BACKGROUND Knowledge of OData 5. QUOTE Today, the tools for capturing data both at the mega-scale and at the milli-scale are just dreadful. After you have captured the data, you need to curate it before you can start doing any kind of data analysis, and we lack good tools for both data curation and data analysis. Jim Gray 6. Problem: Data APIs frequently create more problems than solutions THISTALK IS ABOUT ONE SOLUTION. 7. SURVEY knows what the web is are comfortable w/ HTTP and XML? JSON? have a basic understanding of the term REST have created a Data API 8. Is there really a problem? What is it? QUIZTIME 9. FACEBOOK: WHAT FIELDSWILL I GETWHEN I READ A POST? 10. FACEBOOK: HOW DOYOU LIKE A POST? 11. How do developers know what to do? SO GIVENTHAT NOBODY KNEWTHE ANSWERSTOTHESE QUESTIONS, 12. I GUESSTHEY USE DOCS 13. So is there really a problem? Yes DEVELOPERS DONT HAVETIMETO ACTUALLY READTHE DOCS 14. Can OData Magically cure the problem? No, but it can help. LETS SEE HOW 15. THE PROTOCOL Knowledge of OData 16. THE BASICS OF ODATA Feeds, which are Collections of typed Entities OData services can expose Actions and Functions (v4), Services (v3) OData services expose all these constructs via URIs OData service may also expose a Service Metadata Document 17. FULL SQL LIKE QUERY LANGUAGE HTTP Command (Verb) SQL Command GET SELECT PUT UPDATE POST INSERT DELETE DELETE 18. THE $METADATA ENDPOINT 19. CONVENTIONS http://services.odata.org/OData/OData.svc _______________________________________/ | service root URI http://services.odata.org/OData/OData.svc/Category(1)/Products?$top=2&$orderby=name _______________________________________/ __________________/ _________________/ | | | service root URI resource path query options 20. URL CONVENTIONS $filter /Suppliers?$filter=Address/City eq 'Redmond $orderby /Products?$orderby=ReleaseDate asc, Rating desc $top and $skip /Products?$top=5&$skip=2 $select and $expand /Products?$select=*,Category/Name&$expand=Category 21. COMBINING UEL CONVENTIONS http://.../Players/ ?$skip=10 &$top=2 &filter=substringof(Wood',nameLast) &$orderby=nameLast%20desc &$select=nickname,yearBorn,nameFirst &$format=json 22. PAYLOAD CONVENTIONS Success and error Codes 200 OK, 201 Created, 415 Unsupported MediaType, etc Overall Format JSON AtomPub JSONVerbose Nuances PATCH, Null payloads, etc 23. JSON FORMAT Friendly to Javascript 90% more compact than AtomPub Reads like a custom API Very little OData gunk 24. ATOM FORMAT Atom parsers exist in many frameworks Element fields can be mapped to their Atom counterparts A good example of OData interoperability 25. WHAT ELSE CANYOU DO WITH ODATA? Actions and Functions allow hypermedia-based method calls (non-CRUD operations) Defined conventions for PATCH and deep insert Vocabularies 26. ODATA ISNT ALWAYSTHE BEST FIT OData may not be a good fit for highly opinionated APIs laden with developer intent OData may not be a good fit for bulk data transfer OData may not be a good fit for the APIs that dramatically different in shape than the backend 27. ODATA DOES NOT SUPPORT ALL QUERIES OData doesnt currently support aggregation You cant ask for customers that have at least 2 orders OData doesnt currently support filters expansions You cant ask for a customer and only their orders placed in 2013 OData doesn't support graph queries You can ask friend-of-a-friend type queries, but there are limitations 28. ODATA IS A STANDARD!! OASIS, ISO Ratified in March! 29. WHO USES ODATA? 30. WHAT DOES ODATA GIVE ME AND MY ORGANIZATION? Empower Internal Power Users Empower Existing and Future Customers Monetize Data for untapped Revenue 31. CREATING FEEDW/ ASP.NETWEB API Knowledge of OData 32. ASP.NETWEB API DEMO 33. ODATA BEST PRACTICES (PRODUCER) Always design your OData feed will server-side paging if your entity collections hold large amounts of data. Looks at server-side validation of queries and data updates based on the user credentials sent through HTTP 34. CONSUMING ODATA Knowledge of OData 35. WHAT IF DATA APIS WERE LIKE LINQ? What are the last 50 invoices we sent? context.Invoice.OrderByDescending(i=>i.PostedAt).Take(50); What are the invoices from the last 24 hours? context.Invoice.Where(i=>i.PostedAt > DateTime.Now.AddDays(-1)); How many $1M invoices have we sent? context.Invoice.Where(i=>i.TotalAmount >= 1000000); 36. ODATA BEST PRACTICES (CONSUMER) Use Query Projection to only bring back the entity properties you or your app needs. Think about client-side paging even if their exists server-side paging. Design and implement a client-side data caching function in your app (unless sensitive data). 37. WHY AREWE EXCITED!! 38. WRAP-UP Knowledge of OData 39. The demo projects can be found at: github.com/cwoodruff/ 40. RESOURCES REST http://www.ics.uci.edu/~taylor/documents/2002- REST-TOIT.pdf OData http://odata.org http://odataprimer.com 41. CONTACT ME Chris WoodyWoodruff cwoodruff@live.com Twitter @cwoodruff Skype cwoodruff http://chriswoodruff.com http://deepfriedbytes.com