Building a Fluent API in TypeScript

TriJS

Ryan Hayes

5/10/2016

Who is Ryan?

JS/.NET Engineer

Prefer Ember to Angular and React (for big stuff)

Love TypeScript

Good at Google-ing

• Twitter: @RyannosaurusRex
• Web: ryanhayes.net
• Dat Snapchat: ItsRyanOh
• Wherever Social Medias Are Sold

What's a
Fluent
API?

MethodChaining++;

Method Chaining in jQuery

Each method's return value is the updated element.

Method Chaining in Gulp

Each .pipe() is a new line of configuration.

Method Chaining is:

• Passing the the context to the next method through the return value of the previous method.
• Good for modifying a thing (changing state)
• Sequence of things that happen w/in a context
• Short, sweet, and to the point

Fluent APIs

• Basically Method Chaining
  • With a hierarchy
  • And Sentinel Value
• Great for
  • Builder Objects
  • Queries
  • Configuration
  • Sequences
• Bad For
  • Complexity inside the API
  • Can design yourself into a corner
  • Most regular things

Key Tips

• Be intentional about your API

• TDD shines with Fluent APIs

• Watch sentinel methods that rely on children (transactions)