I have my html and javascript code as below.
<!DOCTYPE html>
<html>
<head>
<style>
#demo {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
</style>
<style>
#demo1 {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
</style>
<div id ="demo"></div>
<div id ="demo1"></div>
<script>
var arr_args = [["ab", "cd"], ["ef", "gh"]];
var j, x = "";
for (i=0; i<2; i++) {
for (j=0; j< 2; j++) {
x = x + arr_args[i][j] + "<br />";
}
if(i == 0) {
document.getElementById("demo").innerHTML = x;
x="";
}
if(i==1) {
document.getElementById("demo1").innerHTML = x;
}
}
</script>
</html>
now instead of me creating demo and demo1 id's. I need the code t do it dynamically. Any help would be appreciated.
You can use backticks as below to get the id as dynamic
document.getElementById(`demo${i == 0 ? '': i }`).innerHTML = x;
var arr_args = [
["ab", "cd"],
["ef", "gh"]
];
var j, x = "";
for (i = 0; i < 2; i++) {
for (j = 0; j < 2; j++) {
x = x + arr_args[i][j] + "<br />";
}
document.getElementById(`demo${i == 0 ? '': i }`).innerHTML = x;
if (i == 0) {
x = "";
}
}
#demo1 {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
#demo {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
<div id="demo"></div>
<div id="demo1"></div>
You can use querySelectorAll to select all divs starting with "demo", then use the corresponding index to update.
var arr_args = [
["ab", "cd"],
["ef", "gh"]
];
var j, x = "";
//Get all divs with an ID starting with demo
var divs = document.querySelectorAll("[id^=demo]");
for (i = 0; i < 2; i++) {
for (j = 0; j < 2; j++) {
x = x + arr_args[i][j] + "<br />";
}
//Update the corresponding div
divs[i].innerHTML = x;
if (i == 0) {
x = "";
}
}
#demo1 {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
#demo {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
<div id="demo"></div>
<div id="demo1"></div>
You probably really want to use a CSS class. .className in JavaScript.
//<![CDATA[
/* js/external.js */
var doc, html, bod, nav, mobile, M, I, S, Q, special, unspecial; // for use on other loads
addEventListener('load', function(){
doc = document; html = doc.documentElement; bod = doc.body; nav = navigator;
mobile = nav.userAgent.match(/Mobi/i) ? true : false;
M = function(tag){
return doc.createElement(tag);
}
I = function(id){
return doc.getElementById(id);
}
S = function(selector, within){
var w = within || doc;
return w.querySelector(selector);
}
Q = function(selector, within){
var w = within || doc;
return w.querySelectorAll(selector);
}
special = function(str){
return str.replace(/&/g, '&').replace(/'/g, ''').replace(/"/g, '"').replace(/</g, '<').replace(/>/g, '>');
}
unspecial = function(str){
return str.replace(/&/g, '&').replace(/'/g, "'").replace(/"/g, '"').replace(/</g, '<').replace(/>/g, '>');
}
var out = I('output'), arr = [['ab', 'cd'], ['ef', 'gh'], ['ij', 'kl', 'mn', 'op'], ['qr', 'st'], ['uv', 'wx', 'yz']], outerDiv, innerDiv;
arr.forEach(function(a){
outerDiv = M('div'); outerDiv.className = 'demo';
a.forEach(function(v){
// no need for `special` in this case but you may have special characters to escape
innerDiv = M('div'); innerDiv.innerHTML = special(v); outerDiv.appendChild(innerDiv);
});
output.appendChild(outerDiv);
});
}); // end load
//]]>
/* css/external.css */
*{
box-sizing:border-box;
}
.demo{
border: 1px solid green; padding: 10px; margin: 20px;
}
<!DOCTYPE html>
<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en' lang='en'>
<head>
<meta charset='UTF-8' /><meta name='viewport' content='width=device-width, height=device-height, initial-scale:1' />
<title>Test Template</title>
<link type='text/css' rel='stylesheet' href='css/external.css' />
<script type='text/javascript' src='js/external.js'></script>
</head>
<body>
<div id='output'></div>
</body>
</html>
Try this:
<!DOCTYPE html>
<html>
<head>
<style>
[id^="demo"] {
border: 1px solid green;
padding: 10px;
margin: 20px;
}
</style>
<div id="section"></div>
<script>
var arr_args = [["ab", "cd"], ["ef", "gh"], ["ij", "kl"]];
arr_args.forEach(myFunction);
function myFunction(item, index) {
document.getElementById("section").innerHTML += "<div id=demo" + index + ">" + item[0] + "<br>" + item[1] + "<div>";
}
</script>
</html>
I am trying to retain the best time value under the id "bestTime", but I keep on getting the following error in Chrome: Cannot read property 'innerHTML' of null at showBestTime.
Not sure what I am doing wrong, I have attached the code below. I am trying to process the best time in the function showBestTime. Thanks in advance!
<html>
<head>
<title>Reaction tester</title>
</head>
<style type="text/css">
#page-container{
width: 1000px;
margin: 0 auto;
height: 800px;
}
body{
margin: 0;
padding: 0;
font-family: Helvetica, Arial, freesans, sans-serif;
}
#shape{
width: 200px;
height: 200px;
background-color: red;
display: none;
position: relative;
}
.time{
font-weight: bold;
}
</style>
<body>
<div id="page-container">
<h1>Test Your Reactions!</h1>
<p>Click on the boxes and circles as quickly as you can!</p>
<p class="time">Your time: <span id="timeTaken"></span></p>
<p class="time">Best time: <span id="bestTime">10</span>s</p>
<div id="shape"></div>
</div>
<script type="text/javascript">
var start=new Date().getTime();
function getRandomColor() {
var letters= "0123456789ABCDEF";
var color= "#";
for (var i=0; i<6; i++) {
color +=letters[Math.floor(Math.random()*16)];
}
return color;
}
function makeShapeAppear(){
var top=Math.random()*400;
var left=Math.random()*800;
var width=(Math.random()*400)+100;
if(Math.random()>0.5){ document.getElementById("shape").style.borderRadius="50%";
} else{
document.getElementById("shape").style.borderRadius="0";
} document.getElementById("shape").style.backgroundColor=getRandomColor();
document.getElementById("shape").style.top=top+"px";
document.getElementById("shape").style.left=left+"px"; document.getElementById("shape").style.width=width+"px"; document.getElementById("shape").style.height=width+"px";
document.getElementById("shape").style.display="block";
start=new Date().getTime();
}
function appearAfterDelay(){
setTimeout(makeShapeAppear, (Math.random() * 2000));
}
function showBestTime(y){ if(y<document.getElementById("besttime").innerHTML){
document.getElementById("besttime").innerHTML=y;
}
}
appearAfterDelay();
document.getElementById("shape").onclick=function(){
document.getElementById("shape").style.display="none";
var end=new Date().getTime();
var timeTaken=(end-start)/1000; document.getElementById("timeTaken").innerHTML=timeTaken+"s";
appearAfterDelay();
showBestTime(timeTaken);
}
</script>
</body>
</html>
You have made a spelling mistake in your selector. You have provided besttime as your selector instead of bestTime. I have added the working code along with.
<html>
<head>
<title>Reaction tester</title>
</head>
<style type="text/css">
#page-container {
width: 1000px;
margin: 0 auto;
height: 800px;
}
body {
margin: 0;
padding: 0;
font-family: Helvetica, Arial, freesans, sans-serif;
}
#shape {
width: 200px;
height: 200px;
background-color: red;
display: none;
position: relative;
}
.time {
font-weight: bold;
}
</style>
<body>
<div id="page-container">
<h1>Test Your Reactions!</h1>
<p>Click on the boxes and circles as quickly as you can!</p>
<p class="time">Your time: <span id="timeTaken"></span></p>
<p class="time">Best time: <span id="bestTime">10</span>s</p>
<div id="shape"></div>
</div>
<script type="text/javascript">
var start = new Date().getTime();
function getRandomColor() {
var letters = "0123456789ABCDEF";
var color = "#";
for (var i = 0; i < 6; i++) {
color += letters[Math.floor(Math.random() * 16)];
}
return color;
}
function makeShapeAppear() {
var top = Math.random() * 400;
var left = Math.random() * 800;
var width = (Math.random() * 400) + 100;
if (Math.random() > 0.5) {
document.getElementById("shape").style.borderRadius = "50%";
} else {
document.getElementById("shape").style.borderRadius = "0";
}
document.getElementById("shape").style.backgroundColor = getRandomColor();
document.getElementById("shape").style.top = top + "px";
document.getElementById("shape").style.left = left + "px";
document.getElementById("shape").style.width = width + "px";
document.getElementById("shape").style.height = width + "px";
document.getElementById("shape").style.display = "block";
start = new Date().getTime();
}
function appearAfterDelay() {
setTimeout(makeShapeAppear, (Math.random() * 2000));
}
function showBestTime(y) {
if (y < document.getElementById("bestTime").innerHTML) {
document.getElementById("bestTime").innerHTML = y;
}
}
appearAfterDelay();
document.getElementById("shape").onclick = function () {
document.getElementById("shape").style.display = "none";
var end = new Date().getTime();
var timeTaken = (end - start) / 1000;
document.getElementById("timeTaken").innerHTML = timeTaken + "s";
appearAfterDelay();
showBestTime(timeTaken);
}
</script>
</body>
</html>
You have span:
<span id="bestTime">
and you query it with
document.getElementById("besttime")
and bestTime is not equal to besttime, so change to:
document.getElementById("bestTime")
I have created a calculator I use for counting carbs for my 7 y/o type 1 diabetic but as I add more values into my array the page is getting too long.
I'm looking for a way to start with a single select for the food name then select the weight and it calculates the carbs. Then have a button to dynamically add another row to the form in order to select a new food item and calculate the results of any further additions.
This is my functional code base:
<html><head>
<meta name = "viewport" content = "initial-scale = 1.0, user-scalable = no">
<title>Carb Calculator</title>
<style>
#container{width: 200px; margin: 0 auto;}
label { font-size:20px; display: inline-block; width: 45%; text-align: right;}
input[type="text"][disabled] {width: 12%; background-color: white; color: black; font-weight: bolder;}
input[type="button"] {}
select {width: 15%}
</style></head>
<body>
<script language="javascript" type="text/javascript">
var myArray = [['Banana',0.1428571429], ['Blackberry',0.1], ['Blueberry',0.1418918919], ['Carrots',0.09836065574], ['Cantaloupe',0.08], ['Cherry Tomato',0.05882352941], ['Cucumber',0.03653846154], ['Green apple',0.1373626374], ['Honeydew',0.09], ['Pear',0.15], ['Raspberry',0.12], ['Plum',0.11], ['Strawberry',0.075], ['Watermelon',0.075]];
function reset(){
var t=0;
for (var i=0; i<myArray.length; i++) {
var v = "val"+i;
document.calc.elements[v].value=0;
}
}
function calculate(){
var t=0;
var tt=0;
for (var i=0; i<myArray.length; i++) {
var v = "val"+i;
var a = "answer"+i;
if(isNaN(parseInt(document.calc.elements[v].value))) {
//document.calc.elements[a].value="";
} else {
tt=(parseInt(document.calc.elements[v].value))* myArray[i][1];
document.calc.elements[a].value=tt.toFixed(1);
t+=tt;
}
}
document.calc.answerTot.value=(t).toFixed(1)
}
document.write("<form name=\"calc\" action=\"post\">");
for (var i=0; i<myArray.length; i++) {
var vv = "val"+i;
var aa = "answer"+i;
document.write("<label>"+myArray[i][0]+":</label> <select name=\""+ vv +"\" onchange=\"calculate()\" >");
for (var j=0; j<301; j++) {
document.write("<option value=" +j+ ">" +j+ "</option>");
}
document.write("</select><input type=text name=" +aa+ " size=5 placeholder=\"Carbs\" disabled><br>");
}
document.write("<br><label for=\"answerTot\">Total carbs: </label> <input type=text name=answerTot size=5 disabled></br></br> <div style=\"text-align:center\"> <input type=button value=Calculate onClick=\"calculate()\"></br></br><input type=button value=Reset onClick=\"reset()\"></div>");
</script></body></html>
Hello there and welcome to StackOverflow!
Your code required a bit of rework and questions like that (more like a task than a question) aren't usually very successful around here.
Having said that, I wrote something that will hopefully help you, the nice thing about it being that if you want to add new types of food you'll only need to add them in the array and the js will take care of it.
Careful with the approximation to 1 digit though, you might lose some carbs in the calculation. Also, please check your carbs, see if I haven't modified anything by mistake.
var myArray = [
['Food', 0],
['Banana', 0.1428571429],
['Blackberry', 0.1],
['Blueberry', 0.1418918919],
['Carrots', 0.09836065574],
['Cantaloupe', 0.08],
['Cherry Tomato', 0.05882352941],
['Cucumber', 0.03653846154],
['Green apple', 0.1373626374],
['Honeydew', 0.09],
['Pear', 0.15],
['Raspberry', 0.12],
['Plum', 0.11],
['Strawberry', 0.075],
['Watermelon', 0.075]
];
function reset() {
var inputs = document.getElementById("calculatorForm").getElementsByTagName("input");
for (var i = 0; i < inputs.length; i++) {
inputs[i].value = "";
}
document.getElementById("answerTot").value = "";
}
function calculate() {
var t = 0;
var tt = 0;
var inputs = document.getElementById("calculatorForm").getElementsByTagName("input");
for (var i = 0; i < inputs.length; i++) {
if (inputs[i].disabled == false) {
if (parseInt(inputs[i].value) > 0) {
tt = (parseInt(inputs[i].value) * getValue(inputs[i].previousSibling.value));
t = +t + +tt;
inputs[i].nextSibling.value = tt.toFixed(1);
}
}
}
console.log(t.toFixed(1));
document.getElementById("answerTot").value = (t).toFixed(1)
}
function add() {
document.getElementById("calculatorForm");
var o = document.createElement("option");
var sel = document.createElement("select");
var inp = document.createElement("input");
var close = document.createElement("span");
var entry = document.createElement("div");
var carbs = document.createElement("input");
carbs.disabled = true;
carbs.className = "result";
entry.className = "entry";
close.className = "remove";
close.innerHTML = "Remove";
for (i = 0; i < myArray.length; i++) {
o = document.createElement("option");
o.value = myArray[i][0];
o.innerHTML = myArray[i][0];
sel.appendChild(o);
}
close.addEventListener("click", function() {
this.parentElement.remove();
calculate();
})
entry.appendChild(sel);
entry.appendChild(inp);
entry.appendChild(carbs);
entry.appendChild(close);
document.getElementById("calculatorForm").appendChild(entry);
}
function getValue(food) {
for (var i = 0; i < myArray.length; i++) {
if (myArray[i][0] == food) return myArray[i][1];
}
}
function getIndex(food) {
for (var i = 0; i < myArray.length; i++) {
if (myArray[i][0] == food) return i;
}
}
window.onload = function() {
add();
}
* {
box-sizing: border-box;
}
#container {
width: 200px;
margin: 0 auto;
}
input[type="text"][disabled] {
outline: none;
border: 1px solid gray;
background-color: white;
color: black;
font-weight: bolder;
}
input[type="button"] {}
select {
width: 15%
}
#calculatorForm {
width: 300px;
margin: auto;
text-align: center;
}
#calculatorForm .entry > * {
width: 140px;
height: 20px;
margin: 5px;
}
#calculatorForm .entry > span {
font-size: 11px;
line-height: 20px;
cursor: pointer;
}
#calculatorForm .entry > .result {
width: 240px;
}
.control {
width: 300px;
margin: auto;
text-align: center;
}
.control>label {
font-size: 11px;
width: 290px;
display: block;
margin: auto;
text-align: left;
margin-bottom: -5px;
}
.control>input {
display: block;
width: 290px;
padding: 5px;
margin: 5px auto;
}
<form name="calc" action="post" id="calculatorForm">
</form>
<div style="text-align:center" class="control">
<label for="answerTot">Total carbs </label>
<input type=text id=answerTot size=5 disabled>
<input type=button value="Add Food" onClick="add()">
<input type=button value=Calculate onClick="calculate()">
<input type=button value=Reset onClick="reset()">
</div>
If anyone wants to see the result, this is what I ended up with. I added a couple event listeners and made the weight value a select rather than an input. Thanks again #Paul for the assistance this is exactly what I was trying to accomplish!
<html>
<head>
<meta name = "viewport" content = "initial-scale = 1.0, user-scalable = no">
<title>Carb Calculator</title>
<style>
{
box-sizing: border-box;
}
#container {
width: 200px;
margin: 0 auto;
}
input[type="text"][disabled] {
outline: none;
border: 1px solid gray;
background-color: white;
color: black;
font-weight: bolder;
}
input[type="button"] {}
select {
width: 15%
}
#calculatorForm {
width: 300px;
margin: auto;
text-align: center;
}
#calculatorForm .entry > * {
width: 145px;
height: 20px;
margin: 2px;
}
#calculatorForm .entry > span {
font-size: 11px;
line-height: 20px;
cursor: pointer;
}
#calculatorForm .entry > .result {
width: 50px;
}
.control {
width: 300px;
margin: auto;
text-align: center;
}
.control>label {
font-size: 11px;
width: 290px;
display: block;
margin: auto;
text-align: left;
margin-bottom: -5px;
}
.control>input {
display: block;
width: 290px;
padding: 5px;
margin: 5px auto;
}
</style>
</head>
<body>
<script language="javascript" type="text/javascript">
var myArray = [
['Food', 0],
['Banana', 0.1428571429],
['Blackberry', 0.1],
['Blueberry', 0.1418918919],
['Carrots', 0.09836065574],
['Cantaloupe', 0.08],
['Cherry Tomato', 0.05882352941],
['Cucumber', 0.03653846154],
['Green apple', 0.1373626374],
['Honeydew', 0.09],
['Pear', 0.15],
['Raspberry', 0.12],
['Plum', 0.11],
['Strawberry', 0.075],
['Watermelon', 0.075]
];
function reset() {
var inputs = document.getElementById("calculatorForm").getElementsByClassName("result");
for (var i = 0; i < inputs.length; i++) {
inputs[i].value = 0;
}
document.getElementById("answerTot").value = "";
}
function calculate() {
var t = 0;
var tt = 0;
var inputs = document.getElementById("calculatorForm").getElementsByClassName("result");
for (var i = 0; i < inputs.length; i++) {
if (inputs[i].disabled == false) {
if (parseInt(inputs[i].value) >= 0) {
tt = (parseInt(inputs[i].value) * getValue(inputs[i].previousSibling.value));
t = +t + +tt;
inputs[i].nextSibling.value = tt.toFixed(1);
}
}
}
console.log(t.toFixed(1));
document.getElementById("answerTot").value = (t).toFixed(1)
}
function add() {
document.getElementById("calculatorForm");
var o = document.createElement("option");
var sel = document.createElement("select");
var inpu = document.createElement("select");
var close = document.createElement("span");
var entry = document.createElement("div");
var carbs = document.createElement("input");
carbs.disabled = true;
carbs.className = "result";
inpu.className = "result";
entry.className = "entry";
close.className = "remove";
close.innerHTML = "Remove";
for (i = 0; i < myArray.length; i++) {
o = document.createElement("option");
o.value = myArray[i][0];
o.innerHTML = myArray[i][0];
sel.appendChild(o);
}
for (var j=0; j<301; j++){
inpu.options[inpu.options.length]=new Option(j,j)
}
close.addEventListener("click", function() {
this.parentElement.remove();
calculate();
})
inpu.addEventListener("change", function() {
calculate();
})
sel.addEventListener("change", function() {
calculate();
})
entry.appendChild(sel);
entry.appendChild(inpu);
entry.appendChild(carbs);
entry.appendChild(close);
document.getElementById("calculatorForm").appendChild(entry);
}
function getValue(food) {
for (var i = 0; i < myArray.length; i++) {
if (myArray[i][0] == food) return myArray[i][1];
}
}
function getIndex(food) {
for (var i = 0; i < myArray.length; i++) {
if (myArray[i][0] == food) return i;
}
}
window.onload = function() {
add();
}
</script>
<form name="calc" action="post" id="calculatorForm"></form>
<div style="text-align:center" class="control"><br>
<label for="answerTot">Total carbs </label>
<input type=text id=answerTot size=5 disabled>
<input type=button value="Add Food" onClick="add()">
<input type=button value=Calculate onClick="calculate()">
<input type=button value=Reset onClick="reset()">
</div>
</body></html>
Here is a small application I came up with that could also suit your needs.
It consists of five files that should be located in the same directory.
Best of health for your child!
Features include:
adding and removing of new food types
adding and removing food to/from multiple lists
changing, increasing and decreasing count of fooditems in lists
manage (add,remove,rename) multiple lists
save and load data in your browser locally
export and import data through a text area to save your data externally.
layout support for both big screen and handheld devices
myCarbCalculator.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Carb Calculator</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<link rel="stylesheet" href="myCarbCalculator.css"></link>
<link rel="stylesheet" media="screen" href="myCarbCalculator-Screen.css"></link>
<link rel="stylesheet" media="handheld" href="myCarbCalculator-Handheld.css"></link>
<script type="text/javascript" src="myCarbCalculator.js"></script>
</head>
<body onload="init();">
<div id="root">
<div id="header">
<button id="btnSaveSettings">save Settings</button>
<button id="btnLoadSettings">load Settings</button>
<button id="btnImportSettings">import Settings</button>
<button id="btnExportSettings">export Settings</button>
<button id="btnResetSettings">reset Settings</button>
</div>
<div id="center">
<div id="content-main">
<div id="c_foodSelector">
<label for="selFoodSelector">select a type of food</label>
<select id="selFoodSelector"></select>
<button id="btnAddSelectedFoodToList">Add Food to List</button>
</div>
<div id="c_foodTable">
<div id="c_foodTableOptions">
<input id="p_foodTableName" value="Your List of Food Items"/>
<button id="btnRenameFoodTable">rename List</button>
<button id="btnNewFoodTable">new List</button>
</div>
<table id="foodTable" class="fill-width"></table>
</div>
</div>
<div id="content-additional">
<div id="c_results">
<label for="inputResultCarbs">Carbs Total</label>
<input id="inputResultCarbs" readonly="readonly"/>
</div/>
<div id="c_foodTableSelection">
<table id="foodTableSelection" class="fill-width"></table>
</div>
<div id="c_output">
<h3>Import/Export</h3>
<textarea id="p_output" class="fill-width"></textarea>
</div/>
</div>
</div>
<div id="footer">
<label for="p_newFoodName">Food Name</label><input id="p_newFoodName"/>
<label for="p_newFoodCarbs">Carb Value</label><input id="p_newFoodCarbs"/>
<button id="btnNewFood">add a new type of food</button>
<button id="btnDeleteSelectedFood">delete Selected type of food</button>
</div>
</div>
</body>
</html>
myCarbCalculator.js
var SAVEID = 'carbCalculatorSettings';
function MyCarbCalculator(){
var self = this;
this.settings = null;
this.initSettings = function(){
self.settings = {
'activeFoodList' : 'default',
'foodData' : {},
'foodList' : {
'default' : {
'label' : 'Your List of Food Items',
'list' : {},
'dateCreated' : '',
'dateChanged' : '',
'notes' : 'This is the default Food List'
}
}
};
};
this.clearContents = function(element){
while (element.firstChild) {
element.removeChild(element.firstChild);
}
};
this.formatDate = function(timestamp){
if(timestamp != ""){
var date = new Date(timestamp);
var monthNames = [
"January", "February", "March",
"April", "May", "June", "July",
"August", "September", "October",
"November", "December"
];
var day = date.getDate();
var monthIndex = date.getMonth();
var year = date.getFullYear();
var hours = date.getHours();
var minutes = date.getMinutes();
var seconds = date.getSeconds();
return day + ' ' + monthNames[monthIndex] + ' ' + year + ' ' + hours + ':'+ minutes + ':'+ seconds;
}
return "---";
};
//////////////////////////////////////////////////////////////////
// Load and Save Data
//////////////////////////////////////////////////////////////////
this.resetSettings = function(){
self.initSettings();
self.updateView();
};
this.saveSettings = function(){
localStorage.setItem(SAVEID,JSON.stringify(self.settings));
};
this.loadSettings = function(){
var saveData = localStorage.getItem(SAVEID);
if(saveData != null && saveData.length > 0){
self.settings = JSON.parse(localStorage.getItem(SAVEID));
self.updateView();
}
else{
self.initSettings();
}
};
this.importSettings = function(){
localStorage.setItem(SAVEID,document.getElementById('p_output').value);
self.loadSettings();
};
this.exportSettings = function(){
document.getElementById('p_output').value = localStorage.getItem(SAVEID);
};
//////////////////////////////////////////////////////////////////
// Manage Food Data
//////////////////////////////////////////////////////////////////
this.updateView = function(){
self.updateFoodSelector();
self.updateFoodTable();
self.updateFoodTableSelection();
self.updateResult();
};
//////////////////////////////////////////////////////////////////
// Manage Food Data
//////////////////////////////////////////////////////////////////
this.newFood = function(){
var name = document.getElementById('p_newFoodName').value;
var carbs = document.getElementById('p_newFoodCarbs').value;
var id = Date.now();
self.settings.foodData[id] = {'name':name,'carbs':carbs};
self.updateFoodSelector();
};
this.removeSelectedFoodData = function(){
var foodSelector = document.getElementById('selFoodSelector');
var foodDataId = foodSelector.options[foodSelector.selectedIndex].value;
delete self.settings.foodData[foodDataId];
self.updateFoodSelector();
}
this.updateFoodSelector = function(){
var foodSelector = document.getElementById('selFoodSelector');
self.clearContents(foodSelector);
for(id in self.settings.foodData){
var food = self.settings.foodData[id];
var item = document.createElement("option");
item.value = id;
item.innerHTML = food.name + " (" + food.carbs + ")";
foodSelector.appendChild(item);
}
};
//////////////////////////////////////////////////////////////////
// Manage current Food Table
//////////////////////////////////////////////////////////////////
this.addSelectedFoodToTable = function(){
var activeFoodListId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeFoodListId];
var foodSelector = document.getElementById('selFoodSelector');
var selectedFoodId = foodSelector.options[foodSelector.selectedIndex].value;
var foodData = self.settings.foodData[selectedFoodId];
var foodItem = {'name':foodData.name,'carbs':foodData.carbs,'count':1};
foodList.list[Date.now()] = foodItem;
foodList.dateChanged = Date.now();
self.updateView();
};
this.updateFoodCount = function(id,value){
var activeFoodListId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeFoodListId];
foodList.list[id].count = value;
foodList.dateChanged = Date.now();
self.updateView();
};
this.removeFoodItem = function(id){
var activeFoodListId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeFoodListId];
delete foodList.list[id];
foodList.dateChanged = Date.now();
self.updateView();
};
this.updateFoodTable = function(){
var activeFoodListId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeFoodListId];
// update the List Name
var foodTableNameElement = document.getElementById('p_foodTableName');
foodTableNameElement.value = foodList.label;
// update the List itself
var foodTable = document.getElementById('foodTable');
self.clearContents(foodTable);
// create the Table Header
var row = document.createElement("tr");
foodTable.innerHTML =
"<tr><th>Name</th><th>Carbs/unit</th><th></th><th>Count</th><th></th></tr>";
for(id in foodList.list){
// create a table structure
var row = document.createElement("tr");
var elm1 = document.createElement("td");
var elm2 = document.createElement("td");
var elm3 = document.createElement("td");
var elm4 = document.createElement("td");
var elm5 = document.createElement("td");
var elm6 = document.createElement("td");
row.appendChild(elm1);
row.appendChild(elm2);
row.appendChild(elm3);
row.appendChild(elm4);
row.appendChild(elm5);
row.appendChild(elm6);
foodTable.appendChild(row);
// create input fields
var food = foodList.list[id];
var inputFoodId = document.createElement("input");
inputFoodId.id = "food-id-" + id;
inputFoodId.type = "hidden";
inputFoodId.value = id;
var inputFoodName = document.createElement("input");
inputFoodName.id = "food-name-" + id;
inputFoodName.setAttribute("readonly","readonly");
inputFoodName.value = food.name;
var inputFoodCarbs = document.createElement("input");
inputFoodCarbs.id = "food-carbs-" + id;
inputFoodCarbs.setAttribute("readonly","readonly");
inputFoodCarbs.style.width = "3em";
inputFoodCarbs.value = food.carbs;
var inputFoodCount = document.createElement("input");
inputFoodCount.id = "food-count-" + id;
inputFoodCount.setAttribute("data-id",id);
inputFoodCount.style.width = "3em";
inputFoodCount.value = food.count;
inputFoodCount.addEventListener("change",function(event){
var inputFoodCount = event.currentTarget;
var id = inputFoodCount.getAttribute("data-id");
var count = inputFoodCount.value;
self.updateFoodCount(id,count);
});
var btnDeleteFoodItem = document.createElement("button");
btnDeleteFoodItem.innerHTML = "remove";
btnDeleteFoodItem.setAttribute("data-id",id);
btnDeleteFoodItem.addEventListener("click",function(event){
var btnDeleteFoodItem = event.currentTarget;
var id = btnDeleteFoodItem.getAttribute("data-id");
self.removeFoodItem(id);
});
var btnCountUp = document.createElement("button");
btnCountUp.innerHTML = "+";
btnCountUp.setAttribute("data-id",id);
btnCountUp.addEventListener("click",function(event){
var id = event.currentTarget.getAttribute("data-id");
var inputFoodCount = document.getElementById("food-count-"+id);
inputFoodCount.value = ++ inputFoodCount.value;
self.updateFoodCount(id,inputFoodCount.value);
});
var btnCountDown = document.createElement("button");
btnCountDown.innerHTML = "-";
btnCountDown.setAttribute("data-id",id);
btnCountDown.addEventListener("click",function(event){
var id = event.currentTarget.getAttribute("data-id");
var inputFoodCount = document.getElementById("food-count-"+id);
inputFoodCount.value = -- inputFoodCount.value;
self.updateFoodCount(id,inputFoodCount.value);
});
// append input fields to the table row
elm1.appendChild(inputFoodId); // this one is invisible anyway
elm1.appendChild(inputFoodName);
elm2.appendChild(inputFoodCarbs);
elm3.appendChild(btnCountDown);
elm4.appendChild(inputFoodCount);
elm5.appendChild(btnCountUp);
elm6.appendChild(btnDeleteFoodItem);
}
};
//////////////////////////////////////////////////////////////////
// Calculate Results
//////////////////////////////////////////////////////////////////
this.calculateCarbsForList = function(listId){
var foodListData = self.settings.foodList[listId].list;
var total = 0;
for(id in foodListData){
var item = foodListData[id];
total = total + (item.carbs * item.count);
}
return total;
};
this.updateResult = function(){
var activeFoodListId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeFoodListId];
var inputResultCarbs = document.getElementById("inputResultCarbs");
inputResultCarbs.value = self.calculateCarbsForList(activeFoodListId);
};
//////////////////////////////////////////////////////////////////
// Food Table Handling
//////////////////////////////////////////////////////////////////
this.renameFoodTable = function(){
var activeTableId = self.settings.activeFoodList;
var foodList = self.settings.foodList[activeTableId];
var newName = document.getElementById('p_foodTableName').value;
foodList.label = newName;
foodList.dateChanged = Date.now();
self.updateView();
};
this.newFoodTable = function(){
var newTableName = document.getElementById('p_foodTableName').value;
var date = Date.now();
self.settings.foodList[date] = {
'label' : newTableName,
'list' : {},
'dateCreated' : date,
'dateChanged' : date,
'notes' : ''
}
self.settings.activeFoodList = date;
self.updateView();
};
this.updateFoodTableSelection = function(){
var foodTableSelection = document.getElementById('foodTableSelection');
self.clearContents(foodTableSelection);
var foodTableLists = self.settings.foodList;
foodTableSelection.innerHTML =
"<tr><th>Name</th><th>last Change</th><th>Carbs</th><th></th><th></th></tr>";
for(var tableId in foodTableLists){
var foodTable = foodTableLists[tableId];
var row = document.createElement("tr");
if(tableId == self.settings.activeFoodList){
row.classList.add("active");
}
var cell1 = document.createElement("td");
var cell2 = document.createElement("td");
var cell3 = document.createElement("td");
var cell4 = document.createElement("td");
var cell5 = document.createElement("td");
cell1.innerHTML = foodTable.label;
cell1.style.cursor = "help";
cell1.title = foodTable.notes;
cell2.innerHTML = self.formatDate(foodTable.dateChanged);
cell2.title = "created: " + self.formatDate(foodTable.dateCreated);
cell3.innerHTML = self.calculateCarbsForList(tableId);
var btnSelectFoodTable = document.createElement("button");
if(tableId == self.settings.activeFoodList)btnSelectFoodTable.disabled = 'disabled';
btnSelectFoodTable.innerHTML = "select";
btnSelectFoodTable.setAttribute("data-tableId",tableId);
btnSelectFoodTable.addEventListener("click",function(event){
var button = event.currentTarget;
self.settings.activeFoodList = button.getAttribute("data-tableId");
self.updateView();
});
cell4.appendChild(btnSelectFoodTable);
var btnDeleteFoodTable = document.createElement("button");
if(tableId == 'default')btnDeleteFoodTable.disabled = 'disabled';
btnDeleteFoodTable.innerHTML = "delete";
btnDeleteFoodTable.setAttribute("data-tableId",tableId);
btnDeleteFoodTable.addEventListener("click",function(event){
var button = event.currentTarget;
var tableId = button.getAttribute("data-tableId");
if(self.settings.activeFoodList = tableId){
self.settings.activeFoodList = "default";
};
delete self.settings.foodList[tableId];
self.updateView();
});
cell5.appendChild(btnDeleteFoodTable);
row.appendChild(cell1);
row.appendChild(cell2);
row.appendChild(cell3);
row.appendChild(cell4);
row.appendChild(cell5);
foodTableSelection.appendChild(row);
}
};
//////////////////////////////////////////////////////////////////
// Add global Events
//////////////////////////////////////////////////////////////////
document.getElementById("btnNewFood").addEventListener("click",this.newFood);
document.getElementById("btnSaveSettings").addEventListener("click",this.saveSettings);
document.getElementById("btnLoadSettings").addEventListener("click",this.loadSettings);
document.getElementById("btnResetSettings").addEventListener("click",this.resetSettings);
document.getElementById("btnImportSettings").addEventListener("click",this.importSettings);
document.getElementById("btnExportSettings").addEventListener("click",this.exportSettings);
document.getElementById("btnDeleteSelectedFood").addEventListener("click",this.removeSelectedFoodData);
document.getElementById("btnAddSelectedFoodToList").addEventListener("click",this.addSelectedFoodToTable);
document.getElementById("btnRenameFoodTable").addEventListener("click",this.renameFoodTable);
document.getElementById("btnNewFoodTable").addEventListener("click",this.newFoodTable);
//////////////////////////////////////////////////////////////////
// Initialize the Data on screen
//////////////////////////////////////////////////////////////////
self.loadSettings();
}
function init(){
var carCalculator = new MyCarbCalculator();
}
myCarbCalculator.css
body,html{
height:100%;
}
/* dont show borders on input fields if read only */
input:-moz-read-only {
border : none;
}
input:read-only {
border : none;
}
/* spacing elements out */
th{
text-align:left;
}
label,input,button,select{
white-space:nowrap;
margin-right: 1em;
}
button{
height:2.5em;
}
#c_results,#c_foodSelector,#c_output,#footer,#header{
padding:1em;
}
/* make result stand out */
#c_results #inputResultCarbs{
font-size: 2em;
color: #882222;
width:4em;
}
#c_results label[for="inputResultCarbs"]{
font-size: 1em;
padding-top:1em;
}
.fill-width{
width:100%;
}
table#foodTableSelection > tr.active{
background-color:yellow;
}
myCarbCalculator-Screen.css
#root{
display:flex;
flex-direction:column;
height:100%;
}
#header{
display:flex;
flex-direction:row;
border-bottom: 1px solid black;
}
#footer{
display:flex;
flex-direction.row;
border-top: 1px solid black;
}
#center{
flex: 1 0;
display:flex;
flex-direction:row;
}
#content-main{
flex: 1 0 auto;
display:flex;
flex-direction: column;
}
#c_foodSelector{
border-bottom: 1px solid black;
}
#c_foodTable{
}
#content-additional{
flex: 0 1 30%;
display:flex;
flex-direction: column;
border-left: 1px solid black;
}
#c_results{
flex: 1 0 auto;
border-bottom: 1px solid black;
}
#c_foodTableSelection{
flex: 1 0 auto;
border-bottom: 1px solid black;
}
#c_output{
flex: 0 1 50%;
}
myCarbCalculator-Handheld.css
#root{
display:flex;
flex-direction:column;
height:100%;
}
#header{
display:flex;
flex-direction:column;
border-top: 1px solid black;
order: 3;
}
#footer{
display:flex;
flex-direction:column;
border-top: 1px solid black;
order: 2;
}
#center{
flex: 1 0;
display:flex;
flex-direction:column;
order: 1;
}
#content-main{
display:flex;
flex-direction: column;
}
#c_foodSelector{
display:flex;
flex-direction:column;
border-bottom: 1px solid black;
}
#c_foodTable{
border-bottom: 1px solid black;
}
#content-additional{
display:flex;
flex-direction: column;
}
#c_results{
flex: 1 0 auto;
border-bottom: 1px solid black;
}
#c_foodTableSelection{
flex: 1 0 auto;
border-bottom: 1px solid black;
}
#c_output{
flex: 0 1 50%;
}
/*******************************************
ADDITONAL STYLES ONLY FOR HANDHELD LAYOUT
*******************************************/
/* spacing out vertically */
label,input,button,select{
margin-bottom: 0.5em;
}
input[id^="food-name"]{
width:4em;
}
#header:before,#footer:before{
text-align:center;
font-size:1em;
font-weight:bold;
margin-bottom:0.5em;
}
#header:before{
content:'Options';
}
#footer:before{
content:'Foodtypes';
}
Technical Notes:
I am using pure Javascript and css. Some styles might not be compatible with older browsers like Internet Explorer prior to Edge.
Saving of data is handled through the browsers local storage.
Import and Export is handled through plain text in "Javascript Object Notation" (JSON).
The Application itself is written as a Javascript Class e.g. Function named MyCarbCalculator which is created and initialized through the bodies onload event and an init() function.
With this example application I'm trying to show how to use Javascript in a structured (pseudo object oriented) way and the power and flexibility of event listeners and unnamed functions e.g. the use of functions as parameters.
Also I am using CSS media descriptors to create a flexible layout that can be customized for both handheld devices and big screens. This is mostly done through the "flexbox" style which allows for very fluid layouts and offers great control over the positioning of elements.
I'm making a slideshow in Javascript with a Play / Pause and Next / Prev. I have manage to slideshow working with play/pause button, but now i wanted to add Next and Prev button to it. Can some one please help me how can i do that.
Here's my HTML:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Simple HTML Slideshow</title>
<style type="text/css">
#slideshow {
margin: 50px auto;
position: relative;
width: 900px;
height: 450px;
padding: 10px;
}
#slideshow > div {
position: absolute;
top: 10px;
left: 10px;
right: 10px;
bottom: 10px;
}
#slideshow > div > img {
width: 100%;
}
#button { text-align: center; }
</style>
<noscript>
Sorry...JavaScript is needed to go ahead.
</noscript>
</head>
<body>
<div id="slideshow">
<div>
<img name="slide" id="imgSlideshow" src="http://themarklee.com/wp-content/uploads/2013/12/snowying.jpg">
</div>
</div>
<div id="button">
Prev
Play/Pause
Next
</div>
</body>
</html>
Here is JavaScript:
<script language="javascript" type="text/javascript">
var i = 0;
var path = new Array();
//var timer = setInterval("slide()",2000);
var timer;
// LIST OF IMAGES
path[0] = "http://themarklee.com/wp-content/uploads/2013/12/snowying.jpg";
path[1] = "http://themarklee.com/wp-content/uploads/2013/12/starlight.jpg";
path[2] = "http://themarklee.com/wp-content/uploads/2013/12/snowstorm.jpg";
path[3] = "http://themarklee.com/wp-content/uploads/2013/12/misty-winter-afternoon.jpg";
function slide() {
document.getElementById("imgSlideshow").src = path[i];
i = (i + 1)%path.length;
//console.log(i);
}
function setTimer(){
if (timer) {
// stop
clearInterval( timer );
timer=null;
}
else {
timer = setInterval("slide()",2000);
}
}
var imgNumber = 1;
var numberOfImg = path.length;
function previousImage() {
if(imgNumber > 1) {
imgNumber--;
}
else {
imgNumber = numberOfImg;
}
document.getElementById("imgSlideshow").src = path[imgNumber-1];
changeCounter(imgNumber, numberOfImg);
}
function nextImage(){
if(imgNumber < numberOfImg){
imgNumber++
}
else{
imgNumber = 1
}
document.getElementById("imgSlideshow").src = path[imgNumber-1];
changeCounter(imgNumber, numberOfImg);
}
function changeCounter(cur, total) {
document.getElementById("counter").innerHTML = cur + "/" + total;
}
document.getElementById("counter").innerHTML = 1 + "/" + path.length;
</script>
Any Help is appreciated and thanks in advance.
Only minor changes in the logic.
var imgNumber = 0;
var path = ["http://themarklee.com/wp-content/uploads/2013/12/snowying.jpg",
"http://themarklee.com/wp-content/uploads/2013/12/starlight.jpg",
"http://themarklee.com/wp-content/uploads/2013/12/snowstorm.jpg",
"http://themarklee.com/wp-content/uploads/2013/12/misty-winter-afternoon.jpg"
];
var numberOfImg = path.length;
var timer = null;
function slide() {
imgNumber = (imgNumber + 1) % path.length;
console.log(imgNumber);
document.getElementById("imgSlideshow").src = path[imgNumber];
changeCounter(imgNumber + 1, numberOfImg);
}
function setTimer() {
if (timer) {
clearInterval(timer);
timer = null;
} else {
timer = setInterval(slide, 2000);
}
return false;
}
function previousImage() {
--imgNumber;
if (imgNumber < 0) {
imgNumber = numberOfImg - 1;
}
document.getElementById("imgSlideshow").src = path[imgNumber];
changeCounter(imgNumber + 1, numberOfImg);
return false;
}
function nextImage() {
++imgNumber;
if (imgNumber > (numberOfImg - 1)) {
imgNumber = 0;
}
document.getElementById("imgSlideshow").src = path[imgNumber];
changeCounter(imgNumber + 1, numberOfImg);
return false;
}
function changeCounter(cur, total) {
document.getElementById("counter").innerHTML = cur + "/" + total;
}
document.getElementById("counter").innerHTML = 1 + "/" + path.length;
#slideshow {
margin: 50px auto;
position: relative;
width: 900px;
height: 450px;
padding: 10px;
}
#slideshow > div {
position: absolute;
top: 10px;
left: 10px;
right: 10px;
bottom: 10px;
}
#slideshow > div > img {
width: 100%;
}
#button {
text-align: center;
}
<div id="slideshow">
<div>
<img name="slide" id="imgSlideshow" src="http://themarklee.com/wp-content/uploads/2013/12/snowying.jpg">
</div>
</div>
<div id="button">
Prev
Play/Pause
Next
</div>
<div id="counter"></div>
I have for example image of Coin.
I want to give a value from 0 to example 20.
0: no coin
1: to one coin
2: 2 coin etc
20: 20 coin
The collection of 6 coins should looks like this:
How can I achieve this goal?
if you prefer pure JS:
var maxI = Math.floor(Math.random() * (21 - 1)) + 1;
var marginCoins = 0;
var coin = [];
for (var i = 0; i < maxI; i++) {
coin[i] = document.createElement('img');
coin[i].src = 'http://placehold.it/75x75';
coin[i].style.position = 'fixed';
coin[i].style.top = marginCoins+'px';
coin[i].style.height = '75px';
coin[i].style.border = '1px solid black';
document.body.appendChild(coin[i]);
marginCoins += 45;
}
$(".coins").each(function(){
var $self = $(this);
var applyCoins = function(){
$self.empty();
var coins = $self.data("coins");
for (var i=coins-1; i>=0; i--) {
var $coin = $("<div></div>").addClass("coin").css("top", (i*20)+"px");
$self.append($coin);
}
};
$self.on("loadCoins", function(){
applyCoins();
});
applyCoins();
});
$("#button").click(function(){
$(".coins").data("coins", $("#input").val()).trigger("loadCoins");
});
.coins {
width: 120px;
height: 120px;
position: relative;
overflow: visible;
}
.coins .coin {
width: 120px;
height: 120px;
position: absolute;
top: 0;
left: 0;
background-color: #FF0000;
border-bottom: 3px solid #333333;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<p>
<input type="text" value="3" id="input" />
<input type="button" value="change" id="button" />
</p>
<div class="coins" data-coins="10"></div>