Going Beyond JSON: Representers, ASTs, and Code

This talk was given at REST Fest. It's a way to view JSON as a language rather than interact directly with the format. It also goes into the idea of the representer pattern.

Transcript

1. Going Beyond JSON: Representers, ASTs, and Code
2. Hi, I'm Stephen. I've thought way too much about JSON @Stephen_Mizell
3. JSON { "name": "John Doe" }
4. JSONx <?xml version="1.0" encoding="UTF-8"?> <json:object xsi:schemaLocation="http://www.datapower.com/schemas/json jsonx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:json="http://www.ibm.com/xmlns/prod/2009/jsonx"> <json:string name="name">John Doe</json:string> </json:object>
5. Ruby { :name => "John Doe" } Or... json.name "John Doe"
6. Refract { "element": "object", "content": [ { "element": "member", "content": { "key": { "element": "string", "content": "name" }, "value": { "element": "string", "content": "John Doe" } } } ] }
7. These are all instruc.ons to build some internal structure of data.
8. Abstract Source Tree A tree representa*on of the abstract syntac*c structure of source code wri5en in a programming language.
9. Homoiconicity The code and representa.on of the code (AST) is the essen.ally the same
10. Syntax + Structure + Seman.cs + Data Find ways to modularize and compose
11. Instead of JSON -> Applica6on Logic Use JSON -> AST -> Applica2on Logic
12. Treat your formats—JSON and others—as languages. Treat them as DSLs. Parse them to canonical structures decoupled from the format itself.
13. Quick Demo
14. Representers
15. Coupling to HAL { "_links": { "item": { "href": "..." } } } // Get the item link doc._links.item.href
16. Coupling to HAL { "_links": { "item": [ { "href": "..." }, { "href": "..." } ] } } // Broken! doc._links.item.href
17. Using a Representer doc.links.hasRel('item'); doc.links.getByRel('item').first(); Decoupled from structure, syntax, and format.
18. Using a Representer doc.links.add('item', 'http://example.com/1'); doc.links.add('item', 'http://example.com/2'); Decoupled from hypermedia formats. Easy to test what your model is independent of formats.
19. Connascence of Type (CoT)
20. Instead of JSON -> Applica6on Logic Use JSON -> Representer -> Applica5on Logic
21. This provides a clearer boundary between your applica5on and the outside world
22. Your data model is not your object model is not your resource model is not your message model. — Mike Amundsen
23. Real world example GraphQL has an AST. OpenAPI does not.
24. Takeaways • Define boundaries • We shouldn't have breaking changes—clients should just degrade • Consider inputs/outputs as languages • Think about canonical structures for crea?ng unity in a world of diversity