observ-set

A Set like structure that's observable

Install

npm install observ-set

Usage

var observSet = require('observ-set')
var observ = require('observ')
var isObserv = require('is-observ')

var set = observSet([{id: 1}, {id: 2}], function (obj, rawObj) {
  return [isObserv(rawObj), obj.id].join()
})

set(function onChange (state) {
  console.log('changed!')
})

set.add({id: 3})
set.delete({id: 2})
set.add(observ({id: 4}))

set.transaction(function (rawSet) {
  set.add({id: 2})
  set.add({id: 6})
  set.delete({id: 1})
})

// Transactional as well
set.forEach(function (value, valueCopy, rawSet) {
  if (value.id < 5) rawSet.delete(value)
})

API

new ObservSet([array], [hashFunction])

Creates a new ObservSet, with initial data obtained from array. hashFunction(value, rawValue) defines how the identity of objects is determined. value is the evaluated value, which might be the contents of another observ or a computed function. rawValue is whatever is passed to ObservSet. Note that hashFunction should return a primitive value, in most cases, if values are to be compared properly. Can also be called without the new keyword.

set()

Standard Observ interface. Returns a copy of the values in the set, as an array.

set(onChange)

Standard Observ interface. Calls onChange(values) with a copy of the values contained in the set, as an array.

set.set(array)

Standard Observ interface. Applies the hashFunction to values of array and overwrites the set with the new values, notifying all listeners.

set.add(value)

Applies hashFunction to value and adds the value if in the set, notifying all listeners if a value was added.

set.clear()

Clears the set and notifies all listeners.

set.delete(value)

Applies hashFunction to value and deletes the value if in the set, notifying all listeners if a value was deleted.

set.entries()

Returns an iterator with [value, value] entries, from a copy of the values contained in the set.

set.forEach(callback, [thisArg])

Starts a transaction around callback(value, value, rawSet), allowing you to modify rawSet and notify all listeners if any changes are made.

set.has(value)

Applies hashFunction to value and returns a Boolean whether the values is contained in the set.

set.values()

Returns an iterator from a copy of the values contained in the set.

set.transaction(callback)

callback(rawSet) is passed a Set-like object that you can safely mutate without notifying listeners before the transaction is over. If no mutations are made, the listeners will not be notified. Transactions can be canceled by returning false.

License

ISC