Develop Reference

How to call JavaScript function repeatedly

I am trying to call the JavaScript function repeatedly after the execution.
function startSlide(){
var products = [
['images/product_images/footwear/footwear_1.jpeg'],
['images/product_images/mobile/mobile_1.jpeg'],
['images/product_images/camera/camera_1.jpeg'],
['images/product_images/fashion/fashion_1.jpeg'],
['images/product_images/laptop/laptop_1.jpeg'],
['images/product_images/furniture/furniture_1.jpeg']
];
for (var i = 0; i < products.length; i++) {
var image = products[i][0];
imgslider(image, i * 800);
}
};
function imgslider(image, timeout)
{
window.setTimeout(function() {
document.getElementById('imgslider').innerHTML = "";
var product = document.getElementById('imgslider');
var elem = document.createElement("img");
product.appendChild(elem);
elem.src = image;
},timeout);
startSlide();
}
The startSlide() function iterates the array and fetch the value from array and call the function imgslider(). the imgslider() function appends the image to the div.
at the end of the imgslider() i am trying to call the startSlide() so that it could continue the execution.... but its not working. how can i do this?

The problem is your code is creating an infinite recursion...
Maintianing your code structure you can add a flag to fix the problem
function startSlide() {
var products = [
['//placehold.it/64X64&text=1'],
['//placehold.it/64X64&text=2'],
['//placehold.it/64X64&text=3'],
['//placehold.it/64X64&text=4'],
['//placehold.it/64X64&text=5']
];
for (var i = 0; i < products.length; i++) {
var image = products[i][0];
imgslider(image, i * 800, i == products.length - 1);
}
};
function imgslider(image, timeout, last) {
window.setTimeout(function() {
document.getElementById('imgslider').innerHTML = "";
var product = document.getElementById('imgslider');
var elem = document.createElement("img");
product.appendChild(elem);
elem.src = image;
if (last) {
setTimeout(startSlide, 800);
}
}, timeout);
}
startSlide()
<div id="imgslider"></div>
If you want to loop, then you can use setInterval() instead
function startSlide() {
var products = [
['//placehold.it/64X64&text=1'],
['//placehold.it/64X64&text=2'],
['//placehold.it/64X64&text=3'],
['//placehold.it/64X64&text=4'],
['//placehold.it/64X64&text=5']
],
i = 0;
setInterval(function() {
imgslider(products[i][0]);
if (++i >= products.length) {
i = 0
}
}, 800);
};
function imgslider(image) {
document.getElementById('imgslider').innerHTML = "";
var product = document.getElementById('imgslider');
var elem = document.createElement("img");
product.appendChild(elem);
elem.src = image;
}
startSlide()
<div id="imgslider"></div>

That's because window.setTimeout only calls the function once, so you should use window.setInterval instead. Something like this:
window.setInterval(function () { /* code to update picture... */ }, 3000);
If it's still not working you can check the console log for errors.
That's F12 in IE or Ctrl+Shift+J in Chrome.

Change properties of a class from time to time

I have two functions. In the first one I increase a variable by adding 100 to it and I put a setInterval so the funcion repeats itself after some time. The other function is a class, a contrusctor to create an object. I want this.x_origen to get increased by adding aumento to it after some time and repeat it. However what I'm getting here is that the first function increases aument and then it finishes and then the second function starts. How can I solve this?
var aument = 0;
function aumento(){
aument = aument + 100;
return aument;
}
setInterval(function () {aumento()}, 1000/50);
function create_class_brick (x_origen_in, y_origen_in, x_final_in, y_final_in, mi_estado, mi_velocidad, mi_id){
this.x_origen = x_origen_in + aumento();
this.y_origen = y_origen_in;
this.x_final = x_final_in + aumento();
this.y_final = y_final_in;
this.estado = mi_estado;
this.velocidad = mi_velocidad;
this.id_elemento = mi_id;
this.DESPLAZAR_LADRILLO = desplazar_ladrillo;
this.F0 = f0;
this.F2 = f2;
this.crear_ladrillo = crear_ladrillo;
this.obtener_x_origen_ladrillo = obtener_x_origen_ladrillo;
this.obtener_y_origen_ladrillo = obtener_y_origen_ladrillo;
this.obtener_x_final_ladrillo = obtener_x_final_ladrillo;
this.obtener_y_final_ladrillo = obtener_y_final_ladrillo;
}

An example on how to wait for the initial call:
function brick (x_origen_in){
this.x_origen = x_origen_in;
}
function aumento(brick){
console.log(brick.x_origen);
brick.x_origen += 100;
setTimeout(aumento.bind(this, brick), 500);
}
var brick = new brick(100);
aumento(brick);
http://jsfiddle.net/x6c08u39/

You can use Object.defineProperty to dynamically generate the value whenever it is accessed.
First, lets simplify the auto-incrementing of aument:
var aument = 0;
function aumento(){
aument += 100;
}
// The first argument for setInterval is the function to execute
// No need to figure out the interval value at runtime as there are no dynamic values
setInterval(aumento, 20); // 1000/50 === 20
Now lets make an object that will have a the correct value:
function create_class_brick (x_origen_in, y_origen_in, x_final_in, y_final_in, mi_estado, mi_velocidad, mi_id){
Object.defineProperty(this, 'x_origen', {
get: function () { return x_origen_in + aument; }
});
// Other stuff
// ...
}
A quick test:
> aument
34100
> var obj = new create_class_brick(23);
undefined
> obj.x_origen
161523
> obj.x_origen
167223
> obj.x_origen
172423

Javascript for loop doesn't work (adding numbers to a total)

I am using Jasmine for JS testing, and unfortunately I can't get the following test to pass.
it('should know the total game score', function() {
frame1 = new Frame;
frame2 = new Frame;
game = new Game;
frame1.score(3, 4);
frame2.score(5, 5);
expect(game.totalScore()).toEqual(17)
});
The error message I get is as follows: Error: Expected 0 to equal 17.
The code is as follows:
function Game() {
this.scorecard = []
};
Game.prototype.add = function(frame) {
this.scorecard.push(frame)
};
// Why is this not working!!???
Game.prototype.totalScore = function() {
total = 0;
for(i = 0; i < this.scorecard.length; i++)
{
total +=this.scorecard[i].rollOne + this.scorecard[i].rollTwo;
}
return total;
};
function Frame() {};
Frame.prototype.score = function(first_roll, second_roll) {
this.rollOne = first_roll;
this.rollTwo = second_roll;
return this
};
Frame.prototype.isStrike = function() {
return (this.rollOne === 10);
};
Frame.prototype.isSpare = function() {
return (this.rollOne + this.rollTwo === 10) && (this.rollOne !== 10)
};
Adding the numbers together manually seems to work e.g. total = game.scorecard[0].rollOne + this.scorecard[0].rollTwo , but the for loop (even though it looks correct) doesn't seem to work. Any help would be greatly appreciated :)

I am not pretty sure, but it seems that you are not calling the "Add" method, so no data is added to the scorecard.

You have to add the Frames to your game i guess
it('should know the total game score', function () {
frame1 = new Frame;
frame2 = new Frame;
game = new Game;
// those lines are missing
game.add(frame1);
game.add(frame2);
frame1.score(3, 4);
frame2.score(5, 5);
expect(17).toEqual(game.totalScore())
});
otherwise, the scorecard-array is empty and the total score is therefore equal to 0.

missing (so no data is added to the scorecard.)
game.Add(frame1);
game.Add(frame2);

Javascript code not working properly(works for some time and crashes)

I've made a javascript slideshow for text but it gets bugged after a couple of loops.
This is what it should be like(don't mind the cursor in gif):
This is what happens after a couple of loops:
The Javascript code:
var quote_array = [
"Aš supratau, kad kuo daugiau dirbu,<br/>tuo labiau man sekasi.",
"Dirbdamas sau malonų darbą<br/>pasieki tobuliausių rezultatų.",
"Tikras darbas yra darbas<br/>kurio tu nemėgsti."
];
var quoteName_array = [
"-Tomas Džefersonas",
"-Aristotelis",
"-Bilas Watersonas"
];
var quote_i = Math.floor(Math.random()*quote_array.length);
var quote_elem;
var quoteName_elem;
var patikrinti
function quoteNext()
{
quote_i = Math.floor(Math.random()*quote_array.length);
if(patikrinti==quote_i)
{
quoteNext();
}
quote_elem.style.opacity = 0;
quoteName_elem.style.opacity = 0;
setTimeout("quoteSlide()",1100);
}
function quoteSlide()
{
patikrinti = quote_i;
quote_elem.innerHTML = quote_array[quote_i];
quoteName_elem.innerHTML = quoteName_array[quote_i];
quote_elem.style.opacity = 1;
quoteName_elem.style.opacity = 1;
setTimeout("quoteNext()",13900);
}

I didn't see the recurion at first, but in quoteNext() you're (randomly) calling quoteNext() a second time - which will add another setTimeout("quoteSlide()",1100) so over time more and more "loops" are running in parallel, leading to total flickering in the end. Change your function to
function quoteNext() {
quote_i = Math.floor(Math.random()*quote_array.length);
if (patikrinti==quote_i) {
quoteNext(); // try again
} else { // but do not continue
quote_elem.style.opacity = 0;
quoteName_elem.style.opacity = 0;
setTimeout(quoteSlide, 1100); // pass functions, not code strings
}
}

I'm trying to stop snow script and clear the page after x seconds

How can I make the snow clear after a certain time. I've tried using variables and the calling a timeout which switches on to false and stops the makesnow() function but that doesn't seem to clear the page at all.
<script language="javascript">
ns6 = document.getElementById;
ns = document.layers;
ie = document.all;
/*******************[AccessCSS]***********************************/
function accessCSS(layerID) { //
if(ns6){ return document.getElementById(layerID).style;} //
else if(ie){ return document.all[layerID].style; } //
else if(ns){ return document.layers[layerID]; } //
}/***********************************************************/
/**************************[move Layer]*************************************/
function move(layer,x,y) { accessCSS(layer).left=x; accessCSS(layer).top = y; }
function browserBredde() {
if (window.innerWidth) return window.innerWidth;
else if (document.body.clientWidth) return document.body.clientWidth;
else return 1024;
}
function browserHoyde() {
if (window.innerHeight) return window.innerHeight;
else if (document.body.clientHeight) return document.body.clientHeight;
else return 800;
}
function makeDiv(objName,parentDiv,w,h,content,x,y,overfl,positionType)
{
// positionType could be 'absolute' or 'relative'
if (parentDiv==null) parentDiv='body';
var oDiv = document.createElement ("DIV");
oDiv.id = objName;
if (w) oDiv.style.width = w;
if (h) oDiv.style.height= h;
if (content) oDiv.innerHTML=content;
if (positionType==null) positionType="absolute";
oDiv.style.position = positionType;
if (x) oDiv.style.left=x; else oDiv.style.left=-2000;
if (y) oDiv.style.top=y; else oDiv.style.top=-2000;
if (overfl) oDiv.style.overflow=overfl; else oDiv.style.overflow="hidden";
eval(' document.'+parentDiv+'.appendChild (oDiv); ');
delete oDiv;
}
var snowC=0;
var x = new Array();
var y = new Array();
var speed = new Array();
var t=0;
var cC = new Array();
var ra = new Array();
function makeSnow() {
x[snowC] = Math.round(Math.random()*(browserBredde()-60));
y[snowC] = 10;
makeDiv("snow"+snowC,"body",32,32,'<img src="http://i693.photobucket.com/albums/vv296/KIBBLESGRAMMY/CAT/Orange-tabby-cat-icon.gif">');
speed[snowC] = Math.round(Math.random()*8)+1;
cC[snowC]=Math.random()*10;
ra[snowC] = Math.random()*7;
snowC++;
}
function moveSnow() {
var r = Math.round(Math.random()*100);
if (r>70 && snowC<20) makeSnow();
for (t=0;t<snowC;t++) {
y[t]+=speed[t];move("snow"+t,x[t],y[t]);
if (y[t]>browserHoyde()-50) {y[t] = 10;x[t] = Math.round(Math.random()*(browserBredde()-60));}
cC[t]+=0.01;
x[t]+=Math.cos(cC[t]*ra[t]);
}
setTimeout('moveSnow()',20);
}
moveSnow();
</script>

makeSnow just adds the snowflakes. Stopping that, as you say, does not clear anything. moveSnow handles the animation, and calls itself at a timeout. If instead of setting a timeout for the next moveSnow each time, you set it up to run in an interval just once, you would have an easier time stopping it.
window.snowAnimation = window.setInterval(moveSnow, 20);
If you add a css class to your snow flakes, it would be easier to target them for deletion.
oDiv.className = 'snowflake';
Then your clear function could look something like:
function clearSnow() {
window.clearTimeout(window.snowAnimation);
var flakes = document.getElementsByTagName('snowflake');
for(var i = 0, l = flakes.length; i < l; i++) {
document.body.removeChild(flakes[i]);
}
}

Timeout doesnt help, it helps you only to stop creating new snowdivs, however if you see makeDiv is the one which creates new divs on to the body, if you clear / display:none the divs which got created on makeDiv i hope it will clear all the divs on the screen.

You need to remove the divs that were created. It might be easier if you give them all some sort of class, like ".snowflake" as you create them (in makeDiv), then start removing them from the dom.

You will have to clear the elements created after the time you wanna stop snow falling.
Following code snippet will help you to clear the elements
if(count < 500){
setTimeout('moveSnow()',20);
}else{
var i = 0;
var elem = document.getElementById('snow'+i);
do{
elem.parentNode.removeChild(elem);
elem = document.getElementById('snow'+ ++i);
}while(elem != null)
}
count++;
you have to create a global variable count.