Develop Reference

Remove all HTML <button> elements with regex

I'm trying to build a program to run a function every time I press a button, and output the returned value. To do this, I use the following HTML:
<h2>Test Results:</h2>
<strong><span id='runs'>0</span> tests</strong><br>
<div id='testResults'>
<button id='test' onClick='this.parentNode.innerHTML = initiatePlanB()'>Begin</button>
</div>
Here's the javascript:
var tests = document.getElementById('runs');
var inner = document.getElementById('testResults').innerHTML;
//Here's the part I can't figure out
var wo = inner.replace(??????, '');
var out = wo + '<br><strong>Test #' + String(Number(tests.innerText) + 1) + '</strong><br>';
tests.innerText = Number(tests.innerText) + 1;
//More stuff here
return out;
Basically, I need either a regex expression, or some other function that can remove any html tag and it's contents.

Why not just find all buttons using getElementsByTagName('button')
and then remove them all?
var testCount = 0;
var tests = document.getElementById('runs');
var inner = document.getElementById('testResults')
function initiatePlanB() {
var buttons = inner.getElementsByTagName('button');
if (buttons) {
for (var i = 0; i < buttons.length; i++) {
buttons[i].remove();
}
}
testCount++;
inner.insertAdjacentHTML('beforeend', '<br><strong>Test #' + testCount + '</strong><br>');
tests.innerText = testCount;
//More stuff here
}
<h2>Test Results:</h2>
<strong><span id='runs'>0</span> tests</strong><br>
<div id='testResults'>
<button id='test' onClick='initiatePlanB()'>Begin</button>
</div>
Though you should probably just hide the buttons, or disable them.

local storage not giving correct results

i am trying to build post it notes. I am reading Head First Series.
I did this code.
but somehow it's no working.
<form action="post">
<input id="note_text" type="text" placeholder="enter your Note">
<input type="button" id="add_button" value="Add Note">
</form>
<ul id="postItNotesList">
<li>This is my very first note.</li>
<li>This is my very Second note.</li>
</ul>
And here is the Js
window.onload=init;
// Add Sticky to Page
function addStickyToPage(value) {
var sticky = document.createElement("li");
span.setAttribute("class", "sticky");
document.getElementById("postItNotesList").appendChild(sticky);
}
// Create and get Sticky Note into the localStorage
function createSticky() {
var value = document.getElementById("note_text").value;
var key = "sticky_" + localStorage.length;
localStorage.setItem(key, value);
addStickyToPage(value);
}
function init() {
var button = document.getElementById("add_button");
button.onclick = createSticky;
for (var i = 0; i < localStorage.length; i++) {
var key = localStorage.key(i);
if (key.substring(0, 6) == "sticky") {
var value = localStorage.getItem(key);
addStickyToPage(value);
}
}
}
So i've buld up a fiddle so that you can easily check it out
Here is the Fiddle
Please tell me where i am doing it wrong.
Thanks.

I have updated your Fiddle. Note : first you should create DOM element and then append text to this element and finally append this node to you body so your code should be like this:
window.onload=init();
function addStickyToPage(value) {
var sticky = document.createElement("li");
sticky.setAttribute("class", "sticky");
var t = document.createTextNode(value);
console.log(t);
sticky.appendChild(t);
document.getElementById("postItNotesList").appendChild(sticky);
}
And also windows.onload = init()with brackets
Thanks

How to create a clickable list of divs with sub items using JavaScript

I want to create a list of clickable divs from arrays using Javascript, where the list structure has to be something like this:-
<div id="outerContainer">
<div id="listContainer">
<div id="listElement">
<div id="itemId"> </div>
<div id="itemTitle"> </div>
<div id="itemStatus"> </div>
</div>
<div id="listElement">
<div id="itemId"> </div>
<div id="itemTitle"> </div>
<div id="itemStatus"> </div>
</div>
</div>
</div>
I want to extract the values of itemId, itemTitle and itemStatus from three arrays itemIdData[ ], itemTitleData[ ] and itemStatusData[ ] respectively, to create the whole list.
Also, when I click on any of the listElements, I want an alert showing the itemId. Can anyone help me with this problem.

If you're using jQuery, then try something like this:
$("#listContainer").on("click", "div", function () {
console.log("jQuery Event Delegation");
alert($(this).find(">:first-child").attr("id"));
});
It's possible to write the same thing without jQuery, but will take further lines of code - I'm conveying the idea of delegation here (there are extensive existing docs and examples on the JQuery site, and here on this site).
NB: the code you're submitted in the question can't(shouldn't) have multiple DOM elements with same IDs (that's what classes are for - for semantically similar elements). Also, trying to emulate a list using divs instead of li elements is perhaps not best practice.

After a bit of experimentation, understood what I was doing wrong and how to get it done.
Here's the code:-
var listContainer = document.createElement("div");
document.getElementById("outerContainer").appendChild(listContainer);
for (var i = 0; i < json.length; i++) {
//create the element container and attach it to listContainer.
var listElement = document.createElement("div");
listElement.id = i;
listElement.className = "listItemContainer";
listElement.addEventListener("click", function(e){
var itemId = e.target.children[1].innerHTML;
alert(itemId);
});
listContainer.appendChild(listElement);
//create and attach the subchilds for listElement.
var itemTitle = document.createElement("span");
itemTitle.innerHTML = postTitleData[i];
itemTitle.id = 'title'+i;
itemTitle.className = "itemTitle";
listElement.appendChild(itemTitle);
var itemId = document.createElement("div");
itemId.innerHTML = postIdData[i];
itemId.id = 'id'+i;
itemId.className = "itemId";
listElement.appendChild(itemId);
var itemStatus = document.createElement("span");
itemStatus.innerHTML = postStatusData[i];
itemStatus.id = 'status'+i;
itemStatus.className = "itemStatus";
listElement.appendChild(itemStatus);
}

Tried something like this which isn't quite working!
var listContainer = document.createElement("div");
document.getElementById("outerContainer").appendChild(listContainer);
var listElement = document.createElement("div");
listContainer.appendChild(listElement);
listElement.className = "listItemContainer";
for (var i = 0; i < json.length; i++) {
var itemId = document.createElement("div");
itemId.innerHTML = idData[i];
listElement.appendChild(itemId);
itemId.className = "itemId";
var itemTitle = document.createElement("div");
itemTitle.innerHTML = titleData[i];
listElement.appendChild(itemTitle);
itemTitle.className = "itemTitle";
var itemStatus = document.createElement("div");
itemStatus.innerHTML = statusData[i];
listElement.appendChild(itemStatus);
itemStatus.className = "itemStatus";
listElement.appendChild(document.createElement("hr"));
var elementId = 'ListElement'+i;
listElement.id = elementId;
listElement.addEventListener("click", function(){
alert(document.getElementById(elementId).innerHTML);
});
}

A good JavaScript to add/remove items from/to array?

folks! Today I created this script that has the following functionality:
add new items to array
list all items from the array
remove an item from the array
There are two functions:
addToFood() - adds the value of input to the array and updates
innerHTML of div
removeRecord(i) - remove a record from the array and updates
innerHTML of div
The code includes 3 for loops and you can see it at - http://jsfiddle.net/menian/3b4qp/1/
My Master told me that those 3 for loops make the solution way to heavy. Is there a better way to do the same thing? Is it better to decrease the loops and try to use splice? Thanks in advance.
HTML
<!-- we add to our foodList from the value of the following input -->
<input type="text" value="food" id="addFood" />
<!-- we call addToFood(); through the following button -->
<input type="submit" value="Add more to food" onClick="addToFood();">
<!-- The list of food is displayed in the following div -->
<div id="foods"></div>
JavaScript
var foodList = [];
function addToFood () {
var addFood = document.getElementById('addFood').value;
foodList.push(addFood);
for (i = 0; i < foodList.length; i++) {
var newFood = "<a href='#' onClick='removeRecord(" + i + ");'>X</a> " + foodList[i] + " <br>";
};
document.getElementById('foods').innerHTML += newFood;
}
function removeRecord (i) {
// define variable j with equal to the number we got from removeRecord
var j = i;
// define and create a new temporary array
var tempList = [];
// empty newFood
// at the end of the function we "refill" it with the new content
var newFood = "";
for (var i = 0; i < foodList.length; i++) {
if(i != j) {
// we add all records except the one == to j to the new array
// the record eual to j is the one we've clicked on X to remove
tempList.push(foodList[i]);
}
};
// make redefine foodList by making it equal to the tempList array
// it should be smaller with one record
foodList = tempList;
// re-display the records from foodList the same way we did it in addToFood()
for (var i = 0; i < foodList.length; i++) {
newFood += "<a href='#' onClick='removeRecord(" + i + ");'>X</a> " + foodList[i] + " <br>";
};
document.getElementById('foods').innerHTML = newFood;
}

You should use array.splice(position,nbItems)
function removeRecord (i) {
foodList.splice(i, 1); // remove element at position i
var newFood = "";
for (var i = 0; i < foodList.length; i++) {
newFood += "<a href='#' onClick='removeRecord(" + i + ");'>X</a> "
+ foodList[i] + " <br>";
};
document.getElementById('foods').innerHTML = newFood;
}
http://jsfiddle.net/3b4qp/5/
Now using JQuery:
$(function(){
$(document).on('click','input[type=submit]',function(){
$('#foods')
.append('<div>X '
+ $('#addFood').val() + '</div>');
});
$(document).on('click','.item',function(){
$(this).parent().remove();
});
});
http://jsfiddle.net/jfWa3/

Your problem isn't the arrays, your problem is this code:
node.innerHTML += newFood;
This code is very, very, very slow. It will traverse all exising DOM nodes, create strings from them, join those strings into one long string, append a new string, parse the result to a new tree of DOM nodes.
I suggest to use a framework like jQuery which has methods to append HTML fragments to existing DOM nodes:
var parent = $('#foods');
...
for (var i = 0; i < foodList.length; i++) {
parent.append( "<a href='#' onClick='removeReco..." );
That will parse the HTML fragments only once.
If you really must do it manually, then collect all the HTML in a local string variable (as suggested by JohnJohnGa in his answer) and then assign innerHTML once.

Here's some tips to, at least, make your code more portable (dunno if it will be better performance wise, but should be, since DOM Manipulation is less expensive)
Tips
First separate your event handle from the HTML
Pass the "new food" as a function paramater
Tie the array elements to the DOM using the ID
Instead of rerendering everything when something changes (using innerHTML in the list), just change the relevant bit
Benefits:
You actually only loop once (when removing elements from the array).
You don't re-render the list everytime something changes, just the element clicked
Added bonus: It's more portable.
Should be faster
Example code:
FIDDLE
HTML
<div id="eventBinder">
<!-- we add to our foodList from the value of the following input -->
<input id="addFood" type="text" value="food" />
<!-- we call addToFood(); through the following button -->
<button id="addFoodBtn" value="Add more to food">Add Food</button>
<!-- The list of food is displayed in the following div
-->
<div id="foods"></div>
</div>
JS
// FoodList Class
var FoodList = function (selectorID) {
return {
foodArray: [],
listEl: document.getElementById(selectorID),
idCnt: 0,
add: function (newFood) {
var id = 'myfood-' + this.idCnt;
this.foodArray.push({
id: id,
food: newFood
});
var foodDom = document.createElement('div'),
foodText = document.createTextNode(newFood);
foodDom.setAttribute('id', id);
foodDom.setAttribute('class', 'aFood');
foodDom.appendChild(foodText);
this.listEl.appendChild(foodDom);
++this.idCnt;
},
remove: function (foodID) {
for (var f in this.foodArray) {
if (this.foodArray[f].id === foodID) {
delete this.foodArray[f];
var delFood = document.getElementById(foodID);
this.listEl.removeChild(delFood);
}
}
}
};
};
//Actual app
window.myFoodList = new FoodList('foods');
document.getElementById('eventBinder').addEventListener('click', function (e) {
if (e.target.id === 'addFoodBtn') {
var food = document.getElementById('addFood').value;
window.myFoodList.add(food);
} else if (e.target.className === 'aFood') {
window.myFoodList.remove(e.target.id);
}
}, false);

Here is another sugestion:
function remove(arr, index) {
if (index >= arr.lenght) { return undefined; }
if (index == 0) {
arr.shift();
return arr;
}
if (index == arr.length - 1) {
arr.pop();
return arr;
}
var newarray = arr.splice(0, index);
return newarray.concat(arr.splice(1,arr.length))
}

How to get child element by ID in JavaScript?

I have following html:
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
How can I get textarea element? I can't use document.getElementById("textid") for it
I'm doing it like this now:
var note = document.getElementById("note");
var notetext = note.querySelector('#textid');
but it doesn't work in IE(8)
How else I can do it? jQuery is ok
Thanks

If jQuery is okay, you can use find(). It's basically equivalent to the way you are doing it right now.
$('#note').find('#textid');
You can also use jQuery selectors to basically achieve the same thing:
$('#note #textid');
Using these methods to get something that already has an ID is kind of strange, but I'm supplying these assuming it's not really how you plan on using it.
On a side note, you should know ID's should be unique in your webpage. If you plan on having multiple elements with the same "ID" consider using a specific class name.
Update 2020.03.10
It's a breeze to use native JS for this:
document.querySelector('#note #textid');
If you want to first find #note then #textid you have to check the first querySelector result. If it fails to match, chaining is no longer possible :(
var parent = document.querySelector('#note');
var child = parent ? parent.querySelector('#textid') : null;

Here is a pure JavaScript solution (without jQuery)
var _Utils = function ()
{
this.findChildById = function (element, childID, isSearchInnerDescendant) // isSearchInnerDescendant <= true for search in inner childern
{
var retElement = null;
var lstChildren = isSearchInnerDescendant ? Utils.getAllDescendant(element) : element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].id == childID)
{
retElement = lstChildren[i];
break;
}
}
return retElement;
}
this.getAllDescendant = function (element, lstChildrenNodes)
{
lstChildrenNodes = lstChildrenNodes ? lstChildrenNodes : [];
var lstChildren = element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].nodeType == 1) // 1 is 'ELEMENT_NODE'
{
lstChildrenNodes.push(lstChildren[i]);
lstChildrenNodes = Utils.getAllDescendant(lstChildren[i], lstChildrenNodes);
}
}
return lstChildrenNodes;
}
}
var Utils = new _Utils;
Example of use:
var myDiv = document.createElement("div");
myDiv.innerHTML = "<table id='tableToolbar'>" +
"<tr>" +
"<td>" +
"<div id='divIdToSearch'>" +
"</div>" +
"</td>" +
"</tr>" +
"</table>";
var divToSearch = Utils.findChildById(myDiv, "divIdToSearch", true);

(Dwell in atom)
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
<script type="text/javascript">
var note = document.getElementById('textid').value;
alert(note);
</script>

Using jQuery
$('#note textarea');
or just
$('#textid');

$(selectedDOM).find();
function looking for all dom objects inside the selected DOM.
i.e.
<div id="mainDiv">
<p>Paragraph 1</p>
<p>Paragraph 2</p>
<div id="innerDiv">
link
<p>Paragraph 3</p>
</div>
</div>
here if you write;
$("#mainDiv").find("p");
you will get tree p elements together. On the other side,
$("#mainDiv").children("p");
Function searching in the just children DOMs of the selected DOM object. So, by this code you will get just paragraph 1 and paragraph 2. It is so beneficial to prevent browser doing unnecessary progress.