Develop Reference

Nested for loop incrementation producing inconsistent result

I'm trying to use the variable of the current iteration of the loop in the nested loop.
However when I execute the following code the loop incorrectly starts at f = 6, and then it correctly iterates over the nested loop.
I've removed all the other code and then it works normally. However I have no clue what could possibly be interfering with the loop. There probably is a reason for it and I wish you guys could help me figure this out - and probably learn something more about why this behaviour occurs the way it does.
for (var f = 0; f < 6; f++) {
var JSONURL = "http://blabla.com/json";
$.ajax( JSONURL, {
dataType: "json"
})
.done(function(json) {
for (var i = 0; i < json.timeslots.length; i++) {
var StartHour = json.timeslots[i].begintijd.split(":")[0];
var StartMinute = json.timeslots[i].begintijd.split(":")[1];
var EndHour = json.timeslots[i].eindtijd.split(":")[0];
var EndMinute = json.timeslots[i].eindtijd.split(":")[1];
//Calculate top distance of block in pixels
if (StartHour < 20) {
var TopDistance = ((parseInt(StartHour) - 9) * 240) + (parseInt(StartMinute) * 4);
}
//Calculate height of block in pixels
var BlockHeight = ((((parseInt(EndHour) * 60) + (parseInt(EndMinute))) - ((parseInt(StartHour) * 60) + (parseInt(StartMinute)))) * 4) - 2.5;
//Generate HTML for blocks
var html_first = '<div data-ix="show-pop-up" class="w-clearfix time-block event-block" style="height:'+BlockHeight+'px; top:'+TopDistance+'px; background-color:'+json.timeslots[i].achtergrondkleur+';">';
if (json.timeslots[i].afbeelding.length > 0) {
var html_mid = '<div class="avatar" style="background-image:url('+json.timeslots[i].afbeelding+');"></div>';
}
else {
html_mid = "";
}
var html_last = '<h4 class="card-title">'+json.timeslots[i].naam+'</h4><div class="time-indication">'+json.timeslots[i].begintijd+'</div><div class="speaker-description">'+json.timeslots[i].functie+'</div><div class="hidden-content"><div class="pop-up-wrapper" style="background-color:'+json.timeslots[i].achtergrondkleur+';"><div class="w-clearfix pop-up-header-background"><div data-ix="hide-pop-up" class="close-icon" id="PopupClose"></div><h3 class="white pop-up-title">'+json.timeslots[i].naam+'</h3><div class="pop-up-subtitle">'+json.timeslots[i].functie+'</div></div><div class="w-clearfix pop-up-body"><div class="pop-up-avatar" style="background-image:url('+json.timeslots[i].afbeelding+');"></div><div class="w-clearfix"><div class="pop-up-card-detail-wrap"><div class="time-label">Begint om</div><div class="pop-up-time-text">'+json.timeslots[i].begintijd+'</div></div><div class="pop-up-card-detail-wrap"><div class="time-label">Eindigt om</div><div class="pop-up-time-text">'+json.timeslots[i].eindtijd+'</div></div><div class="pop-up-card-detail-wrap"><div class="time-label">plek</div><div class="pop-up-time-text">Zaal 1</div></div></div><p class="pop-up-paragraph">'+json.timeslots[i].beschrijving_lang+'</p></div><div class="pop-up-footer">Meer over deze spreker</div></div></div></div>';
var html = html_first+html_mid+html_last;
var TargetDiv = "#Locatie"+f+"Column";
alert("Parent loop increment: "+f);
alert("Child loop increment: "+i);
$(TargetDiv).append(html);
}
});
}

It starts at f = 6 because your callback doesn't get called until after f equals 6
What you may do is something to the effect of:
for (var f = 0; f < 6; f++) {
var JSONURL = "http://blabla.com/json";
$.ajax( JSONURL, {
dataType: "json"
})
.done(handleResponse.bind(null, f));
}
function handleResponse(f, json) {
for (var i = 0; i < json.timeslots.length; i++) {
var StartHour = json.timeslots[i].begintijd.split(":")[0];
var StartMinute = json.timeslots[i].begintijd.split(":")[1];
var EndHour = json.timeslots[i].eindtijd.split(":")[0];
var EndMinute = json.timeslots[i].eindtijd.split(":")[1];
//Calculate top distance of block in pixels
if (StartHour < 20) {
var TopDistance = ((parseInt(StartHour) - 9) * 240) + (parseInt(StartMinute) * 4);
}
//Calculate height of block in pixels
var BlockHeight = ((((parseInt(EndHour) * 60) + (parseInt(EndMinute))) - ((parseInt(StartHour) * 60) + (parseInt(StartMinute)))) * 4) - 2.5;
//Generate HTML for blocks
var html_first = '<div data-ix="show-pop-up" class="w-clearfix time-block event-block" style="height:'+BlockHeight+'px; top:'+TopDistance+'px; background-color:'+json.timeslots[i].achtergrondkleur+';">';
if (json.timeslots[i].afbeelding.length > 0) {
var html_mid = '<div class="avatar" style="background-image:url('+json.timeslots[i].afbeelding+');"></div>';
}
else {
html_mid = "";
}
var html_last = '<h4 class="card-title">'+json.timeslots[i].naam+'</h4><div class="time-indication">'+json.timeslots[i].begintijd+'</div><div class="speaker-description">'+json.timeslots[i].functie+'</div><div class="hidden-content"><div class="pop-up-wrapper" style="background-color:'+json.timeslots[i].achtergrondkleur+';"><div class="w-clearfix pop-up-header-background"><div data-ix="hide-pop-up" class="close-icon" id="PopupClose"></div><h3 class="white pop-up-title">'+json.timeslots[i].naam+'</h3><div class="pop-up-subtitle">'+json.timeslots[i].functie+'</div></div><div class="w-clearfix pop-up-body"><div class="pop-up-avatar" style="background-image:url('+json.timeslots[i].afbeelding+');"></div><div class="w-clearfix"><div class="pop-up-card-detail-wrap"><div class="time-label">Begint om</div><div class="pop-up-time-text">'+json.timeslots[i].begintijd+'</div></div><div class="pop-up-card-detail-wrap"><div class="time-label">Eindigt om</div><div class="pop-up-time-text">'+json.timeslots[i].eindtijd+'</div></div><div class="pop-up-card-detail-wrap"><div class="time-label">plek</div><div class="pop-up-time-text">Zaal 1</div></div></div><p class="pop-up-paragraph">'+json.timeslots[i].beschrijving_lang+'</p></div><div class="pop-up-footer">Meer over deze spreker</div></div></div></div>';
var html = html_first+html_mid+html_last;
var TargetDiv = "#Locatie"+f+"Column";
alert("Parent loop increment: "+f);
alert("Child loop increment: "+i);
$(TargetDiv).append(html);
}
}
What this does is call handleResponse by passing in the value of f at the time that the loop is run.

The problem is not the nested loop, but the asynchronous call inside the loop. To resolve this issue you can use an immediately-invoked-anonymous-function to pass the correct value to your function, like so :
for (var f = 0; f < 6; f++) {
(function(foo) {
//ajax call
//your ajax call will now have the correct number
})(f);
}

JavaScript - Improve my grid search algorithm

I have made my own "GhettoSearch," which is used to find the closest path between 2 given coordinates over a Grid, AKA a "list of coordinates."
The grid is an array like this:
var grid [ [somedata, [x,y,z], somedata], [somedata, [x,y,z], somedata] ]etc..
My start and stop positions is only coordinates, the Z coordinate is irrelevant at the moment.
I can almost get to the end, but some detoures are made because of my cost function.
Here is how the search looks complete: http://i.imgur.com/2ZjQBrh.png
Here is the code I currently use for the search:
var Main = {
GhettoSearch: function(Start, Stop, Grid){
var Pgreed = 1; //From current position to next nearby nodes
var Tgreed = 0.25; //from current position to target node
var Pcost = 0;
var Tcost = 0;
var open = [];
var closed = [];
var aReturn = [];
for (i = 0; i < Grid.length; i++) {
Worldmap.GetNode("Node_" + Grid[i][0]).style.backgroundColor = "#FFFFFF";
Pcost = Heuristics.Distance.Manhattan(Grid[i][1], Start, Pgreed);
Tcost = Heuristics.Distance.Manhattan(Grid[i][1], Stop, Tgreed);
open.push([i, (Pcost + Tcost)]);
}
do {
var TmpData = [0, Infinity];
var TmpForI = null;
for (i = 0; i < open.length; i++) {
if (open[i][1] < TmpData[1]) {
TmpData[0] = open[i][0];
TmpData[1] = open[i][1];
TmpForI = i;
}
}
closed.push(TmpData);
open.splice(TmpForI, 1);
for (i = 0; i < open.length; i++) {
Start = Grid[TmpData[0]][1]; //is now the start for recently closed node
Pcost = Heuristics.Distance.Manhattan(Grid[open[i][0]][1], Start, Pgreed);
Tcost = Heuristics.Distance.Manhattan(Grid[open[i][0]][1], Stop, Tgreed);
open[i] = [open[i][0], (Pcost + Tcost)];
}
} while (open.length > 0);
var PathID = null;
var TmpDist = Infinity;
for (i = 0; i < closed.length; i++) {
var NodeID = Grid[closed[i][0]][0];
var NodeCoords = Grid[closed[i][0]][1];
var NodeCost = closed[i][1];
aReturn.push([NodeID, NodeCoords, NodeCost]);
//var Dist = Heuristics.Distance.Manhattan(NodeCoords, Stop, 1);
if (NodeCost < TmpDist) {
TmpDist = NodeCost;
PathID = i;//Because you will remove the closest cord elese. OR? will u xD
}
}
aReturn.splice(PathID, closed.length);
return aReturn;
}
};
As you can see on the image, while going upwards it goes back and fills the empty spots besides the straight path up, how can I avoid this?
Yes, I have looked at different search aproaches such as BFS and a star, but I have problems implementing this in my own search function

jQuery addClass or other methods doesn't seem to works on an element

(Sorry for my bad english)
I know, this question has been posted so many times, but the threads that I read didn't fix my problem.
I have a grid, with a random black cell drawn for each time I refresh the page. When the time come to "00:01", the cell need to replicate with the neighbors cells, I tried to put a background-color with jQuery, I tried to use attr('id', 'replicant'), I tried addClass... Nothing seem to work :S
Here the code for the draw :
function drawReplicant(replicant, cellTab)
{
for (var i = 0; i < replicant.length; i++) {
if($.inArray(replicant[i], cellTab))
{
var concat = 'row'+replicant[i].x+'col'+replicant[i].y;
$(concat.toString()).addClass("replicant");
}
}
}
And here, the full code :
var lastClicked;
var cellTab = Array();
var replicant = Array();
var neightbors = Array();
var newReplicant = Array();
var randomRow = Math.floor((Math.random() * 10) + 1);
var randomCol = Math.floor((Math.random() * 10) + 1);
var rows = 10;
var cols = 10;
var grid = clickableGrid(rows, cols,randomRow,randomCol,cellTab, function(el,row,col,i){
console.log("You clicked on element:",el);
console.log("You clicked on row:",row);
console.log("You clicked on col:",col);
console.log("You clicked on item #:",i);
$(el).addClass('clicked');
lastClicked = el;
});
document.getElementById("game").appendChild(grid);
function clickableGrid( rows, cols, randomRow, randomCol, cellTab, callback ){
var i=0;
var grid = document.createElement('table');
grid.className = 'grid';
for (var r=0;r<rows;++r){
var tr = grid.appendChild(document.createElement('tr'));
for (var c=0;c<cols;++c){
var cell = tr.appendChild(document.createElement('td'));
$(cell).addClass('row'+r+'col'+c);
if(randomCol == c && randomRow == r)
{
storeCoordinate(r, c, replicant);
$(cell).css('background', '#000000');
}
storeCoordinate(r, c, cellTab);
cell.addEventListener('click',(function(el,r,c,i){
return function(){
callback(el,r,c,i);
}
})(cell,r,c,i),false);
}
}
return grid;
}
function storeCoordinate(xVal, yVal, array)
{
array.push({x: xVal, y: yVal});
}
function replicate(replicant)
{
for (var i = 0; i < replicant.length; i++) {
var supRowX = replicant[i].x-1;
var supRowY = replicant[i].y;
storeCoordinate(supRowX, supRowY, newReplicant);
var subRowX = replicant[i].x+1;
var subRowY = replicant[i].y;
storeCoordinate(subRowX, subRowY, newReplicant);
var supColsX = replicant[i].x;
var supColsY = replicant[i].y-1;
storeCoordinate(supColsX, supColsY, newReplicant);
var subColsX = replicant[i].x;
var subColsY = replicant[i].y+1;
storeCoordinate(subColsX, subColsY, newReplicant);
}
}
function drawReplicant(replicant, cellTab)
{
for (var i = 0; i < replicant.length; i++) {
if($.inArray(replicant[i], cellTab))
{
var concat = 'row'+replicant[i].x+'col'+replicant[i].y;
$(concat.toString()).addClass("replicant");
}
}
}
var w = null; // initialize variable
// function to start the timer
function startTimer()
{
// First check whether Web Workers are supported
if (typeof(Worker)!=="undefined"){
// Check whether Web Worker has been created. If not, create a new Web Worker based on the Javascript file simple-timer.js
if (w==null){
w = new Worker("w.countdown.js");
}
// Update timer div with output from Web Worker
w.onmessage = function (event) {
var bool = false;
document.getElementById("timer").innerHTML = event.data;
if(event.data == "00:01")
{
replicate(replicant);
replicant = newReplicant;
drawReplicant(replicant, cellTab);
}
};
} else {
// Web workers are not supported by your browser
document.getElementById("timer").innerHTML = "Sorry, your browser does not support Web Workers ...";
}
}
// function to stop the timer
function stopTimer()
{
w.terminate();
timerStart = true;
w = null;
}
startTimer();
The replication WORKS, I have my new replicants in my array. But when I loop in this array to draw them, it doesn't seem to work although I'm able to get the cell to draw with :
var concat = 'row'+replicant[i].x+'col'+replicant[i].y;
If my first black cell if at the row4col4 position, this line will return :
row3col4
row5col4
row4col3
row4col5
And then, when the timer will restart, those 5 black cells will replicate with their neighbors, etc.
I use a web worker for the timer, here the code :
var timerStart = true;
function myTimer(d0)
{
// get current time
var d=(new Date()).valueOf();
// calculate time difference between now and initial time
var diff = d-d0;
// calculate number of minutes
var minutes = Math.floor(diff/1000/60);
// calculate number of seconds
var seconds = Math.floor(diff/1000)-minutes*60;
var myVar = null;
// if number of minutes less than 10, add a leading "0"
minutes = minutes.toString();
if (minutes.length == 1){
minutes = "0"+minutes;
}
// if number of seconds less than 10, add a leading "0"
seconds = seconds.toString();
if (seconds.length == 1){
seconds = "0"+seconds;
}
if(seconds >= 20)
{
seconds = "00";
}
// return output to Web Worker
postMessage(minutes+":"+seconds);
}
if (timerStart){
// get current time
var d0=(new Date()).valueOf();
// repeat myTimer(d0) every 100 ms
myVar=setInterval(function(){myTimer(d0)},1000);
// timer should not start anymore since it has been started
timerStart = false;
}
Thanks a lot :-)

Javascript Dynamically added HTML

Please Look at the following code only the last image moves.
http://jsfiddle.net/u8Bg3/
But second one works
http://jsfiddle.net/u8Bg3/1/
As pointed by the Er144 even this works with jquery
http://jsfiddle.net/u8Bg3/14/
I also found out appendchild works but not innerhtml
The difference between two is that in first one html exits in second one it's dynamically created
HTML
<body>
<div class="racetrack" id="racetrack"></div>
<div id="track-tmpl" class="hide">
<div class="track"><div id="player{{ x }}" class="runner"></div></div>
</div>
</body>
JS
var position = [0,40,80,120,80],
racetrack = document.getElementById('racetrack');
track_tmpl = document.getElementById('track-tmpl').innerHTML;
function Players(ele, ptimeout)
{
this.el = ele;
this.i = 0;
this.iterations = 0;
this.stop = 0;
this.timeout = ptimeout;
this.position = 0;
this.animate = function(){
if(this.i !== 0){
this.move((this.position + 5), this.i);
}
if(!this.stop){
if(this.i < 5){
setTimeout(function(_this){
_this.i++;
_this.animate();
},this.timeout,this);
}
if(this.i==5){
this.iterations ++;
if(this.iterations < 50){
this.i = 0;
this.animate();
}
else{
this.el.style.backgroundPosition = '120px 0px';
}
}
}
};
this.start = function(){
this.stop = 0;
this.animate();
};
this.move = function(to,positionIndex){
this.position = to;
this.el.style.backgroundPosition = '-'+position[positionIndex]+'px 0px';
this.el.style.webkitTransform = 'translate('+to+'px)';
this.el.style.mozTransform = 'translate('+to+'px)';
}
}
function Game(noOfPlayers){
this.noOfPlayers = noOfPlayers;
this.players = new Array();
for (var i = 0; i < this.noOfPlayers ; i++){
racetrack.innerHTML = racetrack.innerHTML + track_tmpl.replace('{{ x }}', i);
this.players.push(new Players(document.getElementById('player' + i), (120 + i)));
/* issue here with dynamic added content*/
}
this.start = function(){
for (var i = 0; i < this.noOfPlayers; i++){
this.players[i].start();
}
};
}
var game = new Game(3);
game.start();
Why is that in dynamically added html only the last one moves

The issue is with creating the player(n) object inside the for loop along with the assignments to innerHTML using `+='. The modified fiddle: http://jsfiddle.net/u8Bg3/15/ works fine. Cheers for a good question!
var finalized_tracks= "" ;
for (var i = 0; i < this.noOfPlayers ; i++){
finalized_tracks += track_tmpl.replace('{{ x }}', i);
}
racetrack.innerHTML = racetrack.innerHTML + finalized_tracks;
for (var i = 0; i < this.noOfPlayers ; i++){
this.players.push(new Players(document.getElementById('player'+ i),(120+i)));
}

If you use the jquery:
var element = track_tmpl.replace('{{ x }}', i);
$(racetrack).append(element);
instead of the line where you change the innerHtml of racetrack div, all elements are moving.
However, I'm not sure, why...

theCoder has pretty much nailed the issue with your code there.
Just as an additional thought, you could manually build the necessary divs using javascript instead, it's more long winded however...
for (var i = 0; i < this.noOfPlayers ; i++){
var newTrack = document.createElement("div");
newTrack.id = "track"+i;
newTrack.className = "track";
var newPlayer = document.createElement("div");
newPlayer.id = "player"+i;
newPlayer.className = "runner";
newTrack.appendChild(newPlayer);
racetrack.appendChild(newTrack);
this.players.push(new Players(document.getElementById('player' + i), (120 + i)));
}

This code doesnt work. trying to use a loop to get the sizes of my images the first one comes but the others dont

$j(document).ready(<script type="text/JavaScript">
function getProps(){
var imgwidth = [];
var imgheight = [];
var w, h;
var width = document.getElementById('des').clientWidth;
var height = document.getElementById('des').clientHeight;
img = document.getElementById('des').getElementsByTagName('img').length;
w = document.getElementById('des').getElementsByTagName('img');
h = document.getElementById('des').getElementsByTagName('img');
for ( count = 0; count < img; count++){
imgwidth[count] = w.item(count).clientWidth;
imgheight[count] = h.item(count).clientHeight;
}
</script>);

I think this is what you want, I refactored your code a little:
function getProps()
{
var imgwidth = [];
var imgheight = [];
var images = document.getElementById('des').getElementsByTagName('img');
var count = images.length;
for ( i = 0; i < count; i++)
{
imgwidth[i] = images[i].clientWidth;
imgheight[i] = images[i].clientHeight;
}
console.log(imgwidth);
console.log(imgheight);
}
$(document).ready(function()
{
getProps()
});​
I have set up a jsfiddle for you to demonstrate this: http://jsfiddle.net/JbpdW/
Edit
If you use jQuery (what you obvilously do), you can simplify that process a little by using:
$("#des img").each(function(i)
{
imgwidth[i] = this.clientWidth;
imgheight[i] = this.clientHeight;
});

with jquery it is very short:
$j(function() {
var result=$j.map($('#des img'),function(el,i) {
var $el=$j(el); //optimize
return {width:$el.width(),height:$el.height()};
});
console.log(result);
});
please note that i used array of objects instead of two variables, it easer to work with one variable than with two :)
http://jsbin.com/uzikeh/2/edit