observ-array

observ-array

An array containing observable values

Example

An ObservArray is an observable version of an array, every mutation of the array or mutation of an observable element in the array will cause the ObservArray to emit a new changed plain javascript array.

var ObservArray = require("observ-array")
var ObservStruct = require("observ-struct")
var Observ = require("observ")
var uuid = require("uuid")

function createTodo(title) {
  return ObservStruct({
    id: uuid(),
    title: Observ(title || ""),
    completed: Observ(false)
  })
}

var state = ObservStruct({
  todos: ObservArray([
    createTodo("some todo"),
    createTodo("some other todo")
  ])
})

state(function (currState) {
  // currState.todos is a plain javascript todo
  // currState.todos[0] is a plain javascript value
  currState.todos.forEach(function (todo, index) {
    console.log("todo", todo.title, index)
  })
})

state.todos.get(0).title.set("some new title")
state.todos.push(createTodo("another todo"))

Transactions

Batch changes together with transactions.

var array = ObservArray([ Observ("foo"), Observ("bar") ])

var removeListener = array(handleChange)

array.transaction(function(rawList) {
  rawList.push(Observ("foobar"))
  rawList.splice(1, 1, Observ("baz"), Observ("bazbar"))
  rawList.unshift(Observ("foobaz"))
  rawList[6] = Observ("foobarbaz")
})

function handleChange(value) {
  // this will only be called once
  // changes are batched into a single diff
  value._diff //= [ [1,1,"baz","bazbar","foobar", , "foobarbaz"],
              //    [0,0,"foobaz"] ]
}

Installation

npm install observ-array

Contributors

• Raynos
• Matt McKegg

MIT Licenced