How to change value of multiple iterated element in ejs dynamically? - javascript

Here is my EJS code:
when I click on any iterated button it only changes first element's value. But I want to make other element to change as well. What's wrong with it?
<% for(let i=0; i<10; i++){
%> <h2 id="value">0</h2> <button onclick="btnHandler()">click to change</button> </h1> <%
} %>
<script>
let val = document.getElementById('value');
let start = 0
function btnHandler(){
val.innerHTML = `${start++}`
}
</script>
I try to to change value of iterated element using iterated button with onlclick but it only affect first elements.
I expect to change other element as well.

In the rendered HTML, you have 10 <h2> elements and 10 <button>s, but there is no correspondence between each <button> and "its" <h2> element. Moreover, all the <h2> elements have the same id, and you have only one start counter whereas you need 10.
The following solution relates <h2> elements, <button>s and counters by the index i. I assume this is what you intend to achieve.
<% for(let i=0; i<10; i++){
%> <h2 id="value-<%= i %>">0</h2> <button onclick="btnHandler(<%= i %>)">click to change</button> <%
} %>
<script>
let start = [];
function btnHandler(i){
start[i] = start[i] || 0;
let val = document.getElementById('value-' + i);
val.innerHTML = ++start[i];
}
</script>

Related

How to make dynamic changes in HTML?

So I want to add to a variable every time someone clicks a button on my website. I am very new to HMTL so I don't know how to do this. All the examples I've googled just change text into other text and not adding to a variable.
If someone would like to enlighten me on how to do this I would greatly apricate it.
function changeIt() {
document.getElementById('test').innerHTML = "<h2>Congrats</h2>";
}
<div id="test">
<b> <var> Test </ var> </b>
</div>
<button onclick="changeIt()">Test</button>
var sum = 0;
function changeIt() {
sum++;
document.getElementById('test').innerHTML = `<h2> ${sum} </h2>`;
}
<div id="test">
<b> <var> Test </ var> </b>
</div>
<button onclick="changeIt()">Test</button>
The code you've written in document.innerHTML is correct. For making it dynamic and to add a new Congrats onto the screen instead of just modifying the old one, you need to keep a global counter and loop over it.
let count = 0;
function changeIt() {
count++;
for (let i=0;i<count;i++) {
document.getElementById('test').innerHTML = '';
let h2 = document.getElementById('test').createElement;
h2.innerHTML = "Congrats";
document.getElementById('test').appendChild(h2);
}
}
Since you are calling the changeIt function on every button click it will let you update the count and will loop over the count to add the Congrats 'count' number of times to your div.

Having trouble with onchange and storing numbers in an array via textbox

I am having trouble with my onchange not working and storing numbers in an array via a text box.
What I want the code to do is to get statistics on the numbers inputted into the text box. I do this by having the user input numbers into the text box and hit the Enter key to display those numbers. The numbers should be put into an array before being put into a list to display the inputted numbers. However, I keep getting this error where the onchange is not triggering when hitting the Enter key or clicking off of the text box.
Here is an image of the error I am getting when inspecting the code
With the numbers stored in the array, I want to try to get the Mean of the numbers. But, I keep getting the error "NaN" which makes me think that my numbers are not getting stored into the array properly.
Here is the code:
<html>
<head>
<title>Stats</title>
</head>
<p>Array is called numbers. numbers.sort();</p>
<div id="stats">
<input type ="text" id="value" onchange="list()"> <!-- Getting the Onchange Error here -->
<button id="button1" onclick = "list()">Enter</button>
<ul id="list1">
</ul>
<button id="stat_button" onclick="calculateMean()">Get Statistics</button>
<p id="mean">Mean= </p>
</div>
<script>
function list() {
var liElement = document.createElement("li"); //Creating new list element//
var ulElement = document.getElementById("list1"); //Get the ulElement//
var input = document.getElementById("value").value; //Get the text from the text box//
var numbers = []; //create Array called numbers
numbers.push(input);//adds new items to the array
//for loop//
for(var i=0; i < numbers.length; i++) {
liElement.innerHTML = numbers[0]; //Puts the array into the list for display//
ulElement.appendChild(liElement); //add new li element to ul element//
}
}
function calculateMean() {
var meanTotal = 0;
var meanAverage = 0;
var meanArray = [];
for (var i = 0; i < meanArray.length; i++) {
meanTotal += meanArray[i];
}
meanAverage = (meanTotal / meanArray.length);
document.getElementById("mean").innerHTML = meanAverage;
}
</script>
Try adding it through addEventListener instead of inline like that:
document.getElementById('value').addEventListener('change', function(e){
list()
})
The reason the Mean is always NaN is because your mean array is always an empty array when you start with. I think you were referring to a numbers array here.
You will have to declare the array outside the scope of the 2 functions, since it is the common to both.
And it is always a better idea to decouple Javascript and HTML. Bind your events in JS instead of inline event handlers.
Note: When you read the value from the input, it is a string, so convert it to a number before storing it in the numbers array.
HTML
<p>Array is called numbers. numbers.sort();</p>
<div id="stats">
<input type="text" id="value">
<!-- Getting the Onchange Error here -->
<button id="button1">Enter</button>
<ul id="list1">
</ul>
<button id="stat_button">Get Statistics</button>
<p id="mean">Mean= </p>
</div>
JS
document.getElementById('value').addEventListener('change', list);
document.getElementById('button1').addEventListener('click', list);
document.getElementById('stat_button').addEventListener('click', calculateMean);
var numbers = [];
function list() {
var liElement = document.createElement("li"); //Creating new list element//
var ulElement = document.getElementById("list1"); //Get the ulElement//
var input = document.getElementById("value").value; //Get the text from the text box//
numbers.push(input); //adds new items to the array
//for loop//
for (var i = 0; i < numbers.length; i++) {
liElement.innerHTML = numbers[0]; //Puts the array into the list for display//
ulElement.appendChild(liElement); //add new li element to ul element//
}
}
function calculateMean() {
var meanTotal = 0;
var meanAverage = 0;
for (var i = 0; i < numbers.length; i++) {
meanTotal += numbers[i];
}
meanAverage = (meanTotal / numbers.length);
document.getElementById("mean").innerHTML = meanAverage;
}
jsFiddle

Simpler Javascript counter

I need some help with the click event, I'm trying to have an individual counter that is incremented by the click event that I have on the img. I've tried many variations, I want to resolve this without using jQuery.
<script async>
var count = 0;
var clickerCount = document.getElementsByClassName('clicker');
var cat = {
count : 0,
counter: function(){
this.count++;
clickerCount.textContent = "Kitten Click Count :" + this.count;
console.log("counter function working");
console.log(cat.count);
}
};
function modifyNum(){
cat.counter();
console.log("modifyNum function working");
}
</script>
</head>
<body>
<div style="display:inline">
<div>
<img src="http://placekitten.com/200/296" id="cat0" onclick="modifyNum();">
<p id='clicker'>Kitten Click Count :</p>
</div>
<div>
<img src="http://placekitten.com/200/296" id='cat1' onclick="modifyNum();">
<p id='clicker'>Kitten Click Count :</p>
</div>
</div>
For a start, you are using id='clicker' in two places (IDs are supposed to be unique), and then using document.getElementsByClassName, which returns nothing because you used an ID and not a class.
Once you do change it to a class, document.getElementsByClassName will return an array of elements. You'll have to use clickerCount[0] and so on, or loop through the array.
This example should work. I've separated the HTML from the Javascript because it looks clearer for me. You can use it as an example to expand / create your own in your own way.
Hope it help
HTML:
<div style="display:inline">
<div>
<img src="http://placekitten.com/200/296" id="1" class="countable">
<span>Kitten Click Count :</span><span id="counter-for-1">0</span>
</div>
<div>
<img src="http://placekitten.com/200/296" id="2" class="countable">
<span>Kitten Click Count :</span><span id="counter-for-2">0</span>
</div>
</div>
JS:
var imagesCountable = document.getElementsByClassName("countable");
var counters = [];
for (var i = 0; i < imagesCountable.length; i++) {
counters[imagesCountable[i].id] = 0;
imagesCountable[i].onclick = function(e) {
document.getElementById("counter-for-" + e.currentTarget.id)
.innerHTML = ++counters[e.currentTarget.id];
}
}
var imagesCountable = document.getElementsByClassName("countable");
var counters = [];
for (var i = 0; i < imagesCountable.length; i++) {
counters[imagesCountable[i].id] = 0;
imagesCountable[i].onclick = function(e) {
var cElem = document.getElementById("counter-for-" + e.currentTarget.id);
cElem.innerHTML = ++counters[e.currentTarget.id];
}
}
<div style="display:inline">
<div>
<img src="http://placekitten.com/200/296" id="1" class="countable">
<span>Kitten Click Count :</span><span id="counter-for-1">0</span>
</div>
<div>
<img src="http://placekitten.com/200/296" id="2" class="countable">
<span>Kitten Click Count :</span><span id="counter-for-2">0</span>
</div>
</div>
I have solved this problem in this JSFiddle!
If you can hardcode the IDs then it's easier in my point o view to just manipulate things by ID.
<div>
<img src="http://placekitten.com/200/296" id="cat0" onclick="counter(0);">
<p id='clicker0'>Kitten Click Count :</p>
<input type="hidden" id="counter0" value="0">
</div>
function counter(id) {
var cnt = parseInt(document.getElementById("counter" + id).value);
cnt++;
document.getElementById("counter" + id).value = cnt;
document.getElementById('clicker' + id).innerHTML = 'Kitten Click Count :' + cnt;
}
It's not the same approach but I find it easy to understand.
Hope it helps.
Ok, so first off you have two elements with the id of 'clicker'. You probably meant for those to be classes and ids. So when you call modifynum() it cant locate those because the class doesn't exists. Second, your JS is loading before your HTML elements. So when the JS gets to this line:
var clickerCount = document.getElementsByClassName('clicker');
It is going to find nothing, even if you correct the class names. So you want to move your JS to the footer of your HTML document, or wrap the code in a method that is called on pageLoad().
I think that should take care of it. Your object, for the most part, looks correct.

How could I add the same string on different paragraph multiple time on the same HTML page?

I wish to know the best way to write only once the same thing and repeat inside the same page. For example:
<div>
<p id="description1"></p>
</div>
<div>
<p id="description1"></p>
</div>
--
I wish to write only one time the description1 inside the body. I think this could be achieved using the DOM.
Put the elements in the same class using the class attribute, then get the list of all elements using the getElementsByClassName() DOM function. You can then go over the list using a for loop.
[].forEach.call(document.getElementsByClassName("description"), function(elem) {
elem.innerHTML = "StackOverflow saved my day!";
});
You can even put the text in all elements of the same class using no JavaScript and only CSS by using the content attribute.
First of all, the ID field should be unique per element.
If you give all the tags a class <p class="description"></p> then you can use jQuery to set them all by calling:
$('.description').text('This is the text')
In javascript:
var elements = document.getElementsByClassName("description");
for (var i = 0; i < elements.length; i++) {
elements[i].innerHTML = "This is the text.";
}
Have a look at the solutions proposed here
How to repeat div using jQuery or JavaScript?
this one seems to work pretty well:
html:
<div id="container">data</div>
js:
var container = document.getElementById('container');
function block(mClass, html) {
//extra html you want to store.
return '<div class="' + mClass + '">' + html + '</div>';
}
// code that loops and makes the blocks.
// first part: creates var i
// second: condition, if 'i' is still smaller than three, then loop.
// third part: increment i by 1;
for (var i = 0; i < 3; i++) {
// append the result of function 'block()' to the innerHTML
// of the container.
container.innerHTML += block('block', 'data');
}
JSFIDDLE
Just added with a code by using
getElementsByClassName()
`<html>
<body>
<div class="example">First div element with class="example".</div>
<p class="example">Second paragraph element with class="example".</p>
<p>Click the button to change the text of the first div element with class="example" (index 0).</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.</p>
<script>
function myFunction() {
var x = document.getElementsByClassName("example");
for(var i=0;i< x.length;i++)
x[i].innerHTML = "Hello World!";
}
</script>
</body>
</html>`
If you wish to keep id, change your code like this :
script :
var pcount = 2// # p
var desc = document.getElementById('description1');
for(i=0; i<pcount;i++){
document.getElementById('description' + i).innerHTML = desc;
}
html
<div>
<p id="description1"></p>
</div>
<div>
<p id="description2"></p>
</div>
two elements cannot have same id but can have same class
<head>
<script>
var x = document.getElementsByClassName("description");
for (var i = 0; i < x.length; i++) {
x[i].innerHTML = "This is the text.";
}
</script>
<style>
.description1 { // this will apply the same style to all elements having class as description1
text-align: center;
color: red;
}
</style>
</head>
<body>
<div>
<p class="description1"></p>
</div>
<div>
<p class="description1"></p>
</div>
</body>
See the script tag. this solves your problem

How to get innerHTML of DIV without few inside DIV's?

I have some DIV, what contains HTML with images, styles e.t.c. I want to remove exact div's that contains id = 'quot' or className = 'quote', but i don't understand how i can get not only innerHTML of each tag. For example, < p > and < /p > which don't have innerHTML also should be included in final parsed HTML.
var bodytext = document.getElementById("div_text");
var NewText = "";
if (bodytext.hasChildNodes){
var children = bodytext.childNodes;
for (var i = 0; i < children.length; i++){
if (children[i].id != "quot" && children[i].className != "quote" && children[i].innerText != ""){
NewText = NewText + children[i].innerHTML;
}
}
HTML of source need to be parsed:
<div id="div_text">
<p>
Some Text</p>
<p>
Some Text</p>
<p>
<img alt="" src="localhost/i/1.png" /></p>
<div id="quot" class="quote" />
any text <div>text of inside div</div>
<table><tr><td>there can be table</td></tr></table>
</div>
<p>
</p>
</div>
Desired output:
<p>
Some Text</p>
<p>
Some Text</p>
<p>
<img alt="" src="localhost/i/1.png" /></p>
<p>
</p>
Just grab a reference to the targeted divs and remove them from their respective parents.
Perhaps something a little like this?
EDIT: Added code to perform operation on a clone, rather than the document itself.
div elements don't have .getElementById method, so we search for an element manually.
window.addEventListener('load', myInit, false);
function removeFromDocument()
{
// 1. take car of the element with id='quot'
var tgt = document.getElementById('quot');
var parentNode = tgt.parentNode;
parentNode.removeChild(tgt);
// 2. take care of elements whose class == 'quote'
var tgtList = document.getElementsByClassName('quote');
var i, n = tgtList.length;
for (i=0; i<n; i++)
{
// we really should be checking to ensure that there aren't nested instances of matching divs
// The following would present a problem - <div class='quote'>outer<div class='quote'>inner</div></div>
// since the first iteration of the loop would also remove the second element in the target list,
parentNode = tgtList[i].parentNode;
parentNode.removeChild(tgtList[i]);
}
// 3. remove the containing div
var container = document.getElementById('div_text');
container.outerHTML = container.innerHTML;
}
function cloneAndProcess()
{
var clonedCopy = document.getElementById('div_text').cloneNode(true);
var tgt;// = clonedCopy.getElementById('quot');
var i, n = clonedCopy.childNodes.length;
for (i=0; i<n; i++)
{
if (clonedCopy.childNodes[i].id == 'quot')
{
tgt = clonedCopy.childNodes[i];
var parentNode = tgt.parentNode;
parentNode.removeChild(tgt);
break; // done with for loop - can only have 1 element with any given id
}
}
// 2. take care of elements whose class == 'quote'
var tgtList = clonedCopy.getElementsByClassName('quote');
var i, n = tgtList.length;
for (i=0; i<n; i++)
{
// we really should be checking to ensure that there aren't nested instances of matching divs
// The following would present a problem - <div class='quote'>outer<div class='quote'>inner</div></div>
// since the first iteration of the loop would also remove the second element in the target list,
parentNode = tgtList[i].parentNode;
parentNode.removeChild(tgtList[i]);
}
// 3. remove the containing div
//var container = clonedCopy; //.getElementById('div_text');
//container.outerHTML = container.innerHTML;
console.log(clonedCopy.innerHTML);
}
function myInit()
{
cloneAndProcess();
//removeFromDocument();
}

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