Skip to content

facts.md

Latest commit

 

History

History
27 lines (20 loc) · 1.11 KB

facts.md

File metadata and controls

27 lines (20 loc) · 1.11 KB

Facts

Facts are methods or constants registered with the engine prior to runtime and referenced within rule conditions. Each fact method should be a pure function that may return a computed value or promise. As rule conditions are evaluated during runtime, they retrieve fact values dynamically and use the condition operator to compare the fact result with the condition value.

Methods

constructor(String id, Constant|Function, [Object options]) -> instance

// constant value facts
let fact = new Fact('apiKey', '4feca34f9d67e99b8af2')

// dynamic facts
let fact = new Fact('account-type', function getAccountType() {
  // ...
})

// facts with options:
engine.addFact('account-type', function getAccountType() {
  // ...
}, { cache: false, priority: 500 })

options

  • { cache: Boolean } - Sets whether the engine should cache the result of this fact. Cache key is based on the factId and 'params' passed to it. Default: true
  • { priority: Integer } - Sets when the fact should run in relation to other facts and conditions. The higher the priority value, the sooner the fact will run. Default: 1