listag

LISTAG

List Manager supports Array Operation & Query by Tags.

FEATURES

1. Javascript Array like
   can be used like a normal array with [], length, forEach, map, reduce functions.
2. Tags Associated with Each Item
   can be queried by tags, return a array with items that has the specified tags.
3. Event Support
   listag will emit add and del event which can be listened on.
4. TypeScript Support
   with Type Definition File included.

WHY LISTAG

When we have some of hash values, we put them into a array:

const List = [
  { name: 'tom', value: 1 }
  { name: 'bob', value: 2 }
  { name: 'bob', value: 3 }
]

If we want to get the value out whose name is 'tom', we have to use filter:

const filteredList = List.filter(v => {
  return v.name === 'tom'
})

Listag is a convinience way to do this, with more powerful enhancements.

const lt = new Listag()
lt.add(1, {
  name: 'tom'
})
lt.add([2, 3], {
  name: 'bob'
})

lt.get({
  name: 'bob'
})
.forEach(v => {
  console.log('value of name bob: %s', v)
})

EXAMPLE

Create listag

let lt = new Listtag(1, {
  color: 'blue'
})

let lt2 = new Listtag([2, 3], {
  color: 'green',
  owner: 'tom',
})

Add item(s) to a listag

lt.add(4, {
  color: 'red'
})
lt.add([5, 6], {
  color: 'yellow'
  , owner: 'mike'
})

Del item(s) from a listag

lt.del(4)

ltDel = lt.get({
  color: 'red'
})
lt.del(ltDel)

Get item(s) from a listag

let blueLt = lt.get({
  color: 'blue'
})
blueLt.forEach(i => {
  console.log('items with color blue: %s', i)
})

get can filter the result by exclude some tag value, by add a minus sign - before the value:

let notBlueLt = lt.get({
  color: '-blue'
})

Array Operation

console.log('lt length: %s', lt.length)
console.log('lt[0] = %s', lt[0])

lt.forEach(item => {
  console.log('item: %s', item)
})

lt.map(item => {
  return item * 2
})

lt.filter(item => {
  return item % 2
})

Event

lt.on('add', item => {
  console.log('add item: %s', item)
})

lt.on('del', item => {
  console.log('del item: %s', item)
})

Set Tags to a listag

lt.set({
  lang: 'js'
})

TEST

Unit Test can be found here:

https://github.com/huan/listag/blob/master/tests/

KNOWN ISSUES & SUPPORT

Github Issue - https://github.com/huan/listag/issues

1. Listag can not be instanceof because it has been Proxy-ed

CHANGELOG

v0.8 master

1. Upgrade TypeScript to the latest version
2. DevOps with npm@next

v0.4 (9th Auth 2016)

1. support create listag from listag, keep all tags information right
2. add Listag.item() method to get a ListagItem from Listag, for read tag information

v0.2.3 (7th Aug 2016)

1. add TypeScript Declaration File
2. support to exclude a tag value by add minus sign(-) to value

v0.1.0 (22 Jul 2016)

1. support array with tags powered by ES6 Proxy

TODO

• support for ... in Listag
• support for ... of Listag

AUTHOR

Zhuohuan LI zixia@zixia.net (http://linkedin.com/in/zixia)

COPYRIGHT & LICENSE

• Code & Docs 2016-2018 zixia
• Code released under the ISC license
• Docs released under Creative Commons