aewelg
Last Updated: February 25, 2016
·
496
· kfwerf

Basic LocalStorage Array with limit, uid, search functionality

Hi,

I have made this small little gem that can be quickly implemented to store and grab array info. I needed to store the last amount of items sorted by latest clicked, to oldest. I used this array to do the unshifting, popping, pushing, purging etc. It works best for saving history as it has all the stuff that is needed for it (limited amount, search to delete objects in the array)

Anyway here is the coffeescript, the public part is the stuff you want to use:

    Array::remove = (from, to) ->
    rest = @slice((to or from) + 1 || @length)
    @length = if from < 0 then this.length + from else from
    @push.apply @, rest

# Simple class that makes array extend into the localstorage and updates accordingly
class @LocalStorageArray
    constructor: ( @strUid = undefined, @numLimit = 0 ) ->
        if not @strUid
            @strUid = do () ->
                numTotal = 10
                numString = ''
                for i in [0...numTotal] by 1 then numString = numString + Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1)
                numString


    ## Private

    _fetch: ->
        @arrItems = localStorage.getItem @strUid
        @arrItems = if @arrItems then JSON.parse(@arrItems) else []
        @arrItems
    _update: ->
        localStorage.setItem @strUid, JSON.stringify(@arrItems)
        @_fetch()
    _do: ( fnCallback, arrArguments = [] ) ->
        @_fetch()
        fnCallback.bind(@).apply @, arrArguments
        @_update()
    _checkLimit: ( boolReverse = false ) ->
        if @numLimit
            numDifference = @arrItems.length - @numLimit
            if numDifference > 0
                if boolReverse
                    @arrItems = @arrItems.slice 0, @arrItems.length-numDifference
                else
                    @arrItems = @arrItems.slice numDifference


    ## Public

    setKey: ( @strUid ) ->
    getKey: -> @strUid
    get: -> @_fetch()
    set: ( @arrItems ) -> @_update()
    unshift: ( anyItem ) ->
        @_do (( anyItem ) ->
            @arrItems.unshift anyItem
            @_checkLimit true
        ), [anyItem]
    push: ( anyItem ) -> 
        @_do (( anyItem ) ->
            @arrItems.push anyItem
            @_checkLimit false
        ), [anyItem]
    pop: -> @_do -> @arrItems.pop()
    purge: -> @_do -> @arrItems = []
    remove: ( numIndex ) -> @_do -> @arrItems.remove numIndex
    searchAndDestroy: ( strProperty, strValue ) ->
        objMatched = @matchProperty(strProperty, strValue)
        if objMatched.matched then @remove objMatched.index



    matchProperty: ( strProperty, strValue ) ->
        # Tries to match on property in objects in the array for searching for duplicates
        @_fetch()
        objMatched =
            matched: false
            index: 0

        for objItem in @arrItems by 1
            if typeof objItem is 'object'
                if objItem[strProperty] is strValue
                    objMatched =
                        matched: true
                        index: _i
                    break;

        objMatched