Shared Object - utilizing the 'Flash cookie' | Tutorial

Overview

The Shared Object is like a cookie for flash. It lets flash store some data on the local machine, so between sessions it can remember things. Learn more from wikipedia.
Shared Objects are used to store data on the client machine in much the same way that data is stored in a cookie created through a web browser. The data can only be read by movies originating from the same domain that created the Shared Object. This is the only way Macromedia Flash Player can write data to a user’s machine. Shared Objects can not remember a user’s e-mail address or other personal information unless they willingly provide such information.

I’ve seen many Local Shared Object tutorials and examples, which have users input their name and/or hometown and other filler data. But I wanted to show how to creatively incorporate shared objects into interactions. So I’ve thrown in many simultaneous examples including the uber-simple ‘input your name and I’ll remember it’ approach. I hope I didn’t throw in so much that it got confusing… just let me know if you have any questions or anything is unclear. Keeping it simply and broad there’s only a few things to know about Shared Objects.

Steps

Create them.
- As in create the shared object
Write them.
- As is write to the shared object
Set them.
- As in setting variables in the shared object
Get them.
- As in getting variables back out of the shared object
Clear them.
- As in clearing the shared objec

Actionscript

here’s samples on how to do each of those

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/* Create them. */
//make Local Shared Object named myLocalSO(in as) called "myflashcookie" on disk
var myLocalSO:SharedObject = SharedObject.getLocal("myflashcookie");

/* Write them. */
//flush the SO, write the SO to disk
myLocalSO.flush();

/* Set them. */
//set key's value to specified value in SO
//key is the name of the data
//val is key's value
function setVal(key, val) {
myLocalSO.data[key] = val;
trace(key +" set to "+val);
/* including writing to Shared Object in the setter function */
//flush the SO, write the SO to disk
myLocalSO.flush();
}
/* Get them. */
//get key's value from SO
function getVal(key) {
return myLocalSO.data[key];
trace(myLocalSO.data[key] +" received from "+key);
}
/* Clear them. */
myLocalSO.clear();

Example

here’s my colorful example.
The purple/yellow circle is draggable, so place it where you want it. Enter your name and age in the input boxes. Press the center red ‘Set cookie’ button to copy those values to the shared object that is on your computer now. The red transparent circle represents the cookie positions. You can position the purple/yellow circle from the cookie contents with the dark green ‘Position from cookie’ button, or position it randomly with the blue ‘Position randomly’ button. Erase the cookie with the orange ‘Erase cookie’ button. Toggle easing (animation) with the Bright green button (which changes to dark red when off), it tells the current mode of ease. I have the cookie coordinates displayed and the current coordinates of the purple/yellow circle also displayed.
The cookie includes a date object, which is used to calculate the age of the cookie (watch it reset when you erase the cookie (orange button)).
The ‘All Time Visit’ stat is the only thing that does not get reset when you erase the cookie,

and source code:

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//////////////////////// Initialize variables ///////////////////////

//make Local Shared Object named myLocalSO(in as) called "myflashcookie" on disk
var myLocalSO:SharedObject = SharedObject.getLocal("myflashcookie");
//speed var for easing
var speed = 3;
var w = myCircle._width/2;
//toggle var for easing
var ease = true;
//as var to store alltime cookie
var allTimeVisitCount=0;
countVisit();
cookieFeedback();
//line style for tracing movement
lineStyle(1, 0, 50);

//////////////////////// Functions ///////////////////////

//set key's value to specified value in SO
//key is the name of the data
//val is key's value
function setVal(key, val) {
myLocalSO.data[key] = val;
trace(key +" set to "+val);
//flush the SO, write the SO to disk
myLocalSO.flush();
}
//get key's value from SO
function getVal(key) {
return myLocalSO.data[key];
trace(myLocalSO.data[key] +" received from "+key);
}

function countVisit() {
//if first visit
if (getVal('visitCount') == undefined) {
//create date for now and store in cookie
var todayDate:Date = new Date();
setVal('date', todayDate);
trace("creating date");
//start/reset counting visits
var visitCount = 0;
//notice allTimeVisitCount is not reset, but stored still as a var in actionscript
}

//not first visit
else {
visitCount = getVal('visitCount');
allTimeVisitCount = getVal('allTimeVisitCount');
}
//increment visit counter
setVal('visitCount', visitCount+1);
setVal('allTimeVisitCount', allTimeVisitCount+1);
//feedback of visit counting
visitsFeedback.text = getVal('visitCount');
allTimeVisitsFeedback.text = getVal('allTimeVisitCount');
}
//feedback of cookie contents
function cookieFeedback() {
//in defined print coordinate contents
cookiex.text = getVal('circleX') == undefined ? "no cookie" : getVal('circleX');
cookiey.text = getVal('circleY') == undefined ? "no cookie" : getVal('circleY');

//if not easing assign coordinates from cookie
if (!ease) {
myCookie._x = getVal('circleX');
myCookie._y = getVal('circleY');
}
//set target to cookie coordinates
else {
ctargetx = getVal('circleX');
ctargety = getVal('circleY');
}
//if name then trace cookie contents
if (getVal('name') != undefined) {
visitorFeedback.text = "Returning Visitor";
nameInput.text = getVal('name');
ageInput.text = getVal('age');
}
//no name then a new visitor
else {
visitorFeedback.text = "First Time Visitor";
nameInput.text = "";
ageInput.text = "";
}
calculateCookieAge();
}
function calculateCookieAge() {
//make a date now
todayDate = new Date();
//get the cookie's stored date
cookieDate = getVal('date');
//difference between two dates
cookieDateAge = Math.floor(todayDate - cookieDate);
//convert miliseconds to a timecode
cookieAge.text = msToTimeCode(cookieDateAge);cookieDateAge;
}

//convert miliseconds to a hh:mm:ss
function msToTimeCode(ms) {
//make sure value is within bounds. if a number grater than zero and less than the duration of video
if (isNaN(ms) || ms< 0) {
ms = 0;
}
//find seconds
var sec = ms/1000;
//find minutes
var min = Math.floor(sec/60);
//adjust seconds
sec = sec - min*60;
//find hours
var hour = Math.floor(min/60);
//adjust minutes
min = min - hour*60;
//floor seconds down to whole number
sec = Math.floor(sec);
//make time code with hours
if (hour == 0) {
if (sec < 10) {
sec = "0"+sec;
}
if (min < 10) {
min = "0"+min;
}
var tc = min+":"+sec;
}
//make time code without hours
else {
if (sec < 10) {
sec = "0"+sec;
}
if (min < 10) {
min = "0"+min;
}
var tc = hour+":"+min+":"+sec;
}
return tc;
}

////// Actionscript attached to Objects/handlers //////////

//place data on stage into cookie (circle coordinates and input text)
setCookieButton.onRelease = function() {
setVal('circleX', myCircle._x);
setVal('circleY', myCircle._y);
setVal('name', nameInput.text);
setVal('age', ageInput.text);
//update the display on stage
cookieFeedback();
}
//make random coordinates on stage
randomButton.onRelease = function() {
//if not easing assign coordinates to myCircle
if (!ease) {
myCircle._x = Math.random() * (Stage.width - w);
myCircle._y = Math.random() * (Stage.height - w);
}
//if easing assign coordinates to myCircle's target coords
else {
targetx = Math.random() * (Stage.width - w);
targety = Math.random() * (Stage.height - w);
}
}

myCircle.onPress = function() {
this.startDrag();
dragging = true;
lineStyle(1, 200, 30);
}

myCircle.onRelease = myCircle.onReleaseOutside = function() {
targetx = this._x;
targety = this._y;

lineStyle(1, 0, 50);

dragging = false;
this.stopDrag();
}

myCircle.onEnterFrame = function() {
//print position feedback
currentx.text = this._x;
currenty.text = this._y;
//if eas move to target
if (ease) {
if (!dragging) {
moveTo(this._x+w, this._y+w);
this._x+=(targetx-this._x)/speed;
this._y+=(targety-this._y)/speed;
}
//draw line
lineTo(this._x+w, this._y+w);
}
}

myCookie.onEnterFrame = function() {
//if ease move cookie to target
if (ease) {
this._x+=(ctargetx-this._x)/speed;
this._y+=(ctargety-this._y)/speed;
}
calculateCookieAge();
}

//Position from Cookie
cookieButton.onRelease = function() {
//if not easing set coordinates from cookie
if (!ease) {
myCircle._x = getVal('circleX');
myCircle._y = getVal('circleY');
}
//if easing set target coordinates from cookie
else {
targetx = getVal('circleX');
targety = getVal('circleY');
}
}
easeBtn.onRelease = function () {
//toggle easing
ease = !ease;
//advance the frame of this button...
this.play();
}
clearCookieBtn.onRelease = function() {
//clear the cookie (swipe all data)
myLocalSO.clear();
//restart visit count
countVisit();
//read cookie and give feedback
cookieFeedback();
}

Source

download the source for this example: sharedObject.fla

One Comment

steve

Posted 12 March 2010 at 10:43 am | Permalink

Hi,
Thanks for the creative example. I used these once for a flash header on a website. The client wanted the movie to continue to play as people navigated through different pages and it was pretty amazing.

Thanks!