splice-stream

Stream changes to an array

Data protocol

[[/* Array.prototype.splice arguments */], timestamp, sourceIdentifier]

A splice-stream emits an array, where the first value is an array of parameters compatible with Array.prototype.slice. This represents the delta in change on an array.

The second value is a time stamp which can be used for clever synchronization.

The third value is a source identifier. It's used to identify who created this splice

Example

var SpliceStream = require("splice-stream")
 
var stream1 = SpliceStream()
    , stream2 = SpliceStream()
 
var list1 = stream1.createList()
    , list2 = stream2.createList()
 
list1.on("add", function (item, index) {
    console.log("[LIST1]", item, index)
})
 
list2.on("remove", function (item) {
    console.log("[LIST2]", item)
})
 
stream2.pipe(stream1).pipe(stream2)
 
list2.push("bar") // [LIST1] bar 0
 
console.log("lengths", list1.length(), list2.length()) // lengths 1 1
 
list1.shift() // [LIST2] bar

Movable List

Sometimes you don't want to add / remove items but move them inside a single list. Use a MovableList to represent moves of items

var MovableList = require("splice-stream").MovableList
 
var list1 = MovableList()
 
// When an item moves around in the list
list1.on("move", function (item, index, old) {
    console.log("[MOVE]", item, index, old)
})
 
// Normal list events
list1.on("add", function (item, index) {
    console.log("[ADD]", item, index)
})
 
list1.push("bar")
list1.push("foo")
 
// Wait a tick to register the adds
process.nextTick(function () {
    // Perform movement of items in a single tick for them to register as 
    // move events
    var elem = list1.pop()
    list1.unshift(elem)
})

Installation

npm install splice-stream

Compatible modules

• element-list

Compatible minus one issue

• crdt

Contributors

• Raynos

MIT Licenced