observ's Introduction

observ

A observable value representation

Example

var Observable = require("observ")

var v = Observable("initial value")
v(function onchange(newValue) {
  assert.equal(newValue, "new value")
})
v.set("new value")

var curr = v()
assert.equal(curr, "new value")

What about `dominictarr/observable` ?

Both observ & observable have the same interface of

thing() gets the value
thing.set(...) sets the value
thing(function (value) { ... }) listens to the value.

The way observ and observable differ is in listening.

observ will ONLY call the listener if .set() is invoked.
observable calls the listener IMMEDIATELY and calls it whenever .set() is invoked

observ can be used in a similar fashion to observable by using var watch = require("observ/watch"). You can then just watch(thing, function (value) { ... }) and it will call the listener immediately

Both observ & observable have a computed method with the same interface.

require("observable").compute
require("observ/computed")

Example computed

var Observable = require("observ")
var computed = require("observ/computed")

var one = Observable(1)
var two = Observable(2)

var together = computed([one, two], function (a, b) {
  return a + b
})

assert.equal(together(), 3)
two.set(5)
assert.equal(together(), 7)

Docs

type Observable<A> :
  (() => A) & 
  ((Function<A>) => void) & {
    set: (A) => void
  }
  

observ : (A) => Observable<A>

observ/computed : (
  sources: Array<Observ<T>>,
  lambda: (...args: T) => S
) => Observ<S>