Develop Reference

Javascript - Toggle Multiple Classes onclick

I am trying to toggle multiple classes onclick using vanilla Javascript. What i am trying to do is when a btn is clicked two classes to toggle with another two classes. I have 5 classes in total which are: .menu_btn , .main_nav, .btn_active, .container, .container_active. When i press the .menu_btn i would like the classes .main_nav to toggle with .btn_active and at the same time i would like to have the .container to toggle with .container_active. The class .container is the only one that has 5 elements of that class, the others are single. I have done this using jQuery but i would like to know the way using vanilla Javascript. Hopefully someone can help.
One thing to point out is when i console.log the .btn_active and .container_active i get back [ ] an empty array. Those 2 css classes are not assigned to any element of my project. They are existing only in the css and their purpose is for toggle.
Thanks
jQuery Code:
$(function(){
$(".menu_btn").on("click", function(){
$(".main_nav").toggleClass("btn_active");
$(".container").toggleClass("container_active");
});
});
Vanilla Javascript Code:
var menuBtn = document.getElementsByClassName("menu_btn");
var mainNav = document.getElementsByClassName("main_nav");
var btnActive = document.getElementsByClassName("btn_active");
var container = document.getElementsByClassName("container");
var containerActive = document.getElementsByClassName("container_active");
menuBtn.onclick = function(){
mainNav.classList.toggle(btnActive);
for ( index = 0; index <= container.lenght -1; index++ ){
container[index].classList.toggle(containerActive);
}
};

I have modified your script and created a fiddle so you see how it works: https://jsfiddle.net/eyrpdsc2/
The toggle accepts a string as a parameter, not a Node. So you need to pass 'btn_active' instead of btnActive. Also keep in mind that querySelectorAll returns a NodeList (not an array) so you cannot use forEach.
var menuBtn = document.querySelectorAll(".menu_btn");
var mainNav = document.querySelectorAll(".main_nav");
var container = document.querySelectorAll(".container");
for (var i = 0; i < menuBtn.length; ++i) {
menuBtn[i].addEventListener('click', toggleClasses);
}
function toggleClasses() {
var i = 0;
for (i = 0; i < mainNav.length; ++i) {
mainNav[i].classList.toggle('btn_active');
}
for (i = 0; i < container.length; ++i) {
container[i].classList.toggle('container_active');
}
}

Dynamical Calculator Javascript

It is a calculator which has spans from which I want to take a values(1,2,3, etc.) and two fields: First for displaying what user is typing and the second is for result of calculation.
The question how to get values so when I click on spans it will show it in the second field
Here is the code.
http://jsfiddle.net/ovesyan19/vb394983/2/
<span>(</span>
<span>)</span>
<span class="delete">←</span>
<span class="clear">C</span>
<span>7</span>
<span>8</span>
<span>9</span>
<span class="operator">÷</span>
....
JS:
var keys = document.querySelectorAll(".keys span");
keys.onclick = function(){
for (var i = 0; i < keys.length; i++) {
alert(keys[i].innerHTML);
};
}

var keys = document.querySelectorAll(".keys span");
for (var i = 0; i < keys.length; i++) {
keys[i].onclick = function(){
alert(this.innerHTML);
}
}
keys is a NodeList so you cannot attach the onclick on that. You need to attach it to each element in that list by doing the loop. To get the value you can then simple use this.innerHTML.
Fiddle

This should get you started.. you need to get the value of the span you are clicking and then append it into your result field. Lots more to get this calculator to work but this should get you pointed in the right direction.
Fiddle Update: http://jsfiddle.net/vb394983/3/
JavaScript (jQuery):
$(".keys").on("click","span",function(){
var clickedVal = $(this).text();
$(".display.result").append(clickedVal);
});

You can set a click event on the span elements if you use JQuery.
Eg:
$("span").click(
function(){
$("#calc").val($("#calc").val() + $(this).text());
});
See:
http://jsfiddle.net/vb394983/6/
That's just to answer your question but you should really give the numbers a class such as "valueSpan" and the operators a class such as "operatorSpan" and apply the events based on these classes so that the buttons behave as you'd expect a calculator to.

http://jsfiddle.net/vb394983/7/
var v="",
max_length=8,
register=document.getElementById("register");
// attach key events for numbers
var keys = document.querySelectorAll(".keys span");
for (var i = 0; l = keys.length, i < l; i++) {
keys[i].onclick = function(){
cal(this);
}
};
// magic display number and decimal, this formats like a cash register, modify for your own needs.
cal = function(e){
if (v.length === self.max_length) return;
v += e.innerHTML;
register.innerHTML = (parseInt(v) / 100).toFixed(2);
}

Using JQuery will make your life much easier:
$('.keys span').click(function() {
alert(this.innerHTML);
});

How do I filter an unorderded list to display only selected items using Javascript?

I have this JSFiddle where I am trying to make it so that the items in an unordered list are visible only if the option selected in a drop down matches their class. List items may have multiple classes, but so long as at least one class matches, the item should be made visible.
The Javascript looks like this:
function showListCategories() {
var selection = document.getElementById("listDisplayer").selectedIndex;
var unHidden = document.getElementsByClassName(selection);
for (var i = 0; i < unHidden.length; i++) {
unHidden[i].style.display = 'visible';
}
};
The idea is that it gets the current selection from the drop down, creates an array based on the matching classes, then cycles through each item and sets the CSS to be hidden on each one.
However, it's not working. Can anyone tell me where I'm going wroing?
Note that I haven't yet coded the "show all" option. I think I'll probably be able to figure that out once I have this first problem solved.

In your fiddle change load script No wrap - in <head>.
Just change your function like following
function showListCategories() {
var lis = document.getElementsByTagName('li');
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'none';
}
//above code to reset all lis if they are already shown
var selection = document.getElementById("listDisplayer").value;
lis = document.getElementsByClassName(selection);
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'block';
}
};
and in css it should be none not hidden
.cats, .rats, .bats {
display: none;
}
If you want to show all li when showAll is selected, add all classes to all lis.

You have a few things going on. First, your fiddle is not setup correctly, if you open the console you'll see:
Uncaught ReferenceError: showListCategories is not defined
This means that the function doesn't exist at the point you attach the event or that the function is out of scope, because by default jsFiddle will wrap your code in the onLoad event. To fix it you need to load the script as No wrap - in <body>.
Second, there's no such thing as a display:visible property in CSS. The property you want to toggle is display:none and display:list-item, as this is the default style of <li> elements.
Now, to make this work, it is easier if you add a common class to all items, let's say item, that way you can hide them all, and just show the one you want by checking if it has a certain class, as opposed to querying the DOM many times. You should cache your selectors, it is not necessary to query every time you call the function:
var select = document.getElementById('listDisplayer');
var items = document.getElementsByClassName('item');
function showListCategories() {
var selection = select.options[select.selectedIndex].value;
for (var i=0; i<items.length; i++) {
if (items[i].className.indexOf(selection) > -1) {
items[i].style.display = 'list-item';
} else {
items[i].style.display = 'none';
}
}
}
Demo: http://jsfiddle.net/E2DKh/28/

First there is no property in Css like display:hidden; it should be display: none;
here is the solution please not that i am doing it by targeting id finished
Js function
var selection = document.getElementById("listDisplayer");
var list = document.getElementsByTagName('li');
selection.onchange = function () {
var value = selection.options[selection.selectedIndex].value; // to get Value
for (var i = 0; i < list.length; i++) {
if (list[i].className.indexOf(value) > -1) {
list[i].style.display = "list-item";
} else {
list[i].style.display = "none"
}
}
}
css Code
.cats, .rats, .bats {
display: none;
}
JSFIDDLE

You have many things wrong in your code and a wrong setting in the jsFiddle. Here's a working version that also implements the "all" option:
Working demo: http://jsfiddle.net/jfriend00/5Efc5/
function applyToList(list, fn) {
for (var i = 0; i < list.length; i++) {
fn(list[i], list);
}
}
function hide(list) {
applyToList(list, function(item) {
item.style.display = "none";
});
}
function show(list) {
applyToList(list, function(item) {
item.style.display = "block";
});
}
function showListCategories() {
var value = document.getElementById("listDisplayer").value;
var itemList = document.getElementById("itemList");
var items = itemList.getElementsByTagName("li");
if (value === "all") {
show(items);
} else {
// hide all items by default
hide(items);
show(itemList.getElementsByClassName(value));
}
}
Changes made:
You have to fetch the .value of the select to see what the value was of the option that was picked. You were using the selectedIndex which is just a number.
A common technique for displaying only a set of objects is to hide all of them, then show just the ones you want. Since the browser only does one repaint for the entire operation, this is still visually seamless.
When finding items that match your class, you should be searching only the <ul>, not the entire document. I added an id to that <ul> tag so it can be found and then searched.
To save code, I added some utility functions for operating on an HTMLCollection or nodeList.
Tests for the "all" option and shows them all if that is selected
Changed the jsFiddle to the Head option so the code is available in the global scope so the HTML can find your change handler function.
Switched style settings to "block" and "none" since "visible" is not a valid setting for style.display.

jQuery/javascript replace tag type

Is there an easy way to loop through all td tags and change them to th? (etc).
My current approach would be to wrap them with the th and then remove the td, but then I lose other properties etc.

jQuery.replaceTagName
The following is a jQuery plugin to replace the tag name of DOM elements.
Source
(function($) {
$.fn.replaceTagName = function(replaceWith) {
var tags = [],
i = this.length;
while (i--) {
var newElement = document.createElement(replaceWith),
thisi = this[i],
thisia = thisi.attributes;
for (var a = thisia.length - 1; a >= 0; a--) {
var attrib = thisia[a];
newElement.setAttribute(attrib.name, attrib.value);
};
newElement.innerHTML = thisi.innerHTML;
$(thisi).after(newElement).remove();
tags[i] = newElement;
}
return $(tags);
};
})(window.jQuery);
Minified Source
(function(e){e.fn.replaceTagName=function(t){var n=[],r=this.length;while(r--){var i=document.createElement(t),s=this[r],o=s.attributes;for(var u=o.length-1;u>=0;u--){var a=o[u];i.setAttribute(a.name,a.value)}i.innerHTML=s.innerHTML;e(s).after(i).remove();n[r]=i}return e(n)}})(window.jQuery);
Usage
Include the above minified source in your javascript after jQuery.
Then you can use the plugin like this:
$('div').replaceTagName('span'); // replace all divs with spans
Or in your case this:
$('td').replaceTagName('th');
jQuery selectors work as expected
$('.replace_us').replaceTagName('span'); // replace all elements with "replace_us" class with spans
$('#replace_me').replaceTagName('div'); // replace the element with the id "replace_me"
More resources
jsFiddle with Qunit tests

Completely untested, but giving this a whirl:
$("td").each(function(index) {
var thisTD = this;
var newElement = $("<th></th>");
$.each(this.attributes, function(index) {
$(newElement).attr(thisTD.attributes[index].name, thisTD.attributes[index].value);
});
$(this).after(newElement).remove();
});
I'm looking and looking at it, and I can't think of a reason why it wouldn't work!
1) loop through each td element
2) create a new th element
3) for each of those td's, loop over each of its attributes
4) add that attribute and value to the new th element
5) once all attributes are in place, add the element to the DOM right after the td, and remove the td
Edit: works fine: http://jsbin.com/uqofu3/edit

$("td").each(function() {
var tmp = $('<div/>').append($(this).clone(true)).html().replace(/td/i,'th');
$(this).after(tmp).remove();
});
or pure DOM
function replaceElm(oldTagName, newTagName, targetElm) {
var target = targetElm || window.document;
var allFound = target.getElementsByTagName(oldTagName);
for (var i=0; i<allFound.length; i++) {
var tmp = document.createElement(newTagName);
for (var k=0; k<allFound[i].attributes.length; k++) {
var name = allFound[i].attributes[k].name;
var val = allFound[i].attributes[k].value;
tmp.setAttribute(name,val);
}
tmp.innerHTML = allFound[i].innerHTML;
allFound[i].parentNode.insertBefore(tmp, allFound[i]);
allFound[i].parentNode.removeChild(allFound[i]);
}
}
replaceElm('td','th',document.getElementsByTagName('table')[0]);
DOM is always faster: http://jsperf.com/replace-tag-names

This might work, but I haven't tested it extensively:
var tds = document.getElementsByTagName("td");
while(tds[0]){
var t = document.createElement("th");
var a = tds[0].attributes;
for(var i=0;i<a.length;i++) t.setAttribute(a[i].nodeName,a[i].nodeValue);
t.innerHTML = tds[0].innerHTML;
tds[0].parentNode.insertBefore(t,tds[0]);
tds[0].parentNode.removeChild(tds[0]);
}
I hope it helps in some way.

Slight addition to #GlenCrawford answer, to also preserve inner text with the line:
newElement.text($(value).text());
All together now:
$("td").each(function(index) {
var thisTD = this;
var newElement = $("<th></th>");
newElement.text($(value).text());
$.each(this.attributes, function(index) {
$(newElement).attr(thisTD.attributes[index].name, thisTD.attributes[index].value);
});
$(this).after(newElement).remove();
});

Well this question is pretty old but this could help anyway: the only jQuery plugin that actually works as expected (you can't reuse the returned object in the other one, to add attributes for example):
jQuery.fn.extend({
replaceTagName: function(replaceWith) {
var tags=[];
this.each(function(i,oldTag) {
var $oldTag=$(oldTag);
var $newTag=$($("<div />").append($oldTag.clone(true)).html().replace(new RegExp("^<"+$oldTag.prop("tagName"),"i"),"<"+replaceWith));
$oldTag.after($newTag).remove();
tags.push($newTag.get(0));
});
return $(tags);
}
});
Besides the basic $("td").replaceTagName("th"); you can also chain calls like $("td").replaceTagName("th").attr("title","test");
Minified version:
jQuery.fn.extend({replaceTagName:function(a){var b=[];this.each(function(d,c){var e=$(c);var f=$($("<div />").append(e.clone(true)).html().replace(new RegExp("^<"+e.prop("tagName"),"i"),"<"+a));e.after(f).remove();b.push(f.get(0))});return $(b)}});

This is a bit cleaner than #GlenCrawford's answer and additionally copies the children of the replaced element.
$('td').each(function(){
var newElem = $('<th></th>', {html: $(this).html()});
$.each(this.attributes, function() {
newElem.attr(this.name, this.value);
});
$(this).replaceWith(newElem);
});

disable all the elements in html

How can we disable all the elements in html through javascript.The easiest way...

I suggest to do it the "Lightbox"-style way.
Add an absolute positioned, transparent, full screen div Layer above the Page.
This way, the user can't even click on a Link.
To give the user a visual feedback that the page is disabled,
you can make the div e. g. 50% transparent black.
BTW, here is also a jQuery Plugin that uses a similar technique.

The easiest way is to put all form elements you want to disable inside a <fieldset> and then disable the fieldset itself.
An example: http://jsfiddle.net/xdkf9b8j/1/
If you don't want the border around the fieldset, remove it per css.

Try this,
function disableForm(theform) {
if (document.all || document.getElementById) {
for (i = 0; i < theform.length; i++) {
var formElement = theform.elements[i];
if (true) {
formElement.disabled = true;
}
}
}
}
Or else you can try this too, as RaYell said
function disableForm() {
var inputs = document.getElementsByTagName("input");
for (var i = 0; i < inputs.length; i++) {
inputs[i].disabled = true;
}
var selects = document.getElementsByTagName("select");
for (var i = 0; i < selects.length; i++) {
selects[i].disabled = true;
}
var textareas = document.getElementsByTagName("textarea");
for (var i = 0; i < textareas.length; i++) {
textareas[i].disabled = true;
}
var buttons = document.getElementsByTagName("button");
for (var i = 0; i < buttons.length; i++) {
buttons[i].disabled = true;
}
}
To disable the whole page you can find some info here,

I don't know why you would need that but this will work:
// this will disable all input elements
var elems = document.getElementsByTagName('input');
var len = elems.length;
for (var i = 0; i < len; i++) {
elems[i].disabled = true;
}

All the form elements (inputs, selects, textareas) within a form, are accesible through the form.elements HTMLCollection, you can iterate the collection disabling each element:
function disableForm(form) {
var length = form.elements.length,
i;
for (i=0; i < length; i++) {
form.elements[i].disabled = true;
}
}
Usage examples:
disableForm(document.forms[0]);
disableForm(document.getElementById('formId'));

Once i had to create a tutorial for my website. I needed to disable all interactions on a page excluding some elements. To do so i used this method:
First make sure to remove all events bindings from your page elements. You can do this by using:
$('*').unbind();
Next disable all links on your page:
$('a').each(function(){$(this).click(function(){return false;})});
and disable all inputs:
$('input').attr('disabled', true);
The code needs to be executed at the end of your document. BTW you may exclude some elements within jquery selector to keep them active.

To lock:
var controls = document.querySelectorAll("button, input, select, textarea");
for (var c of controls) {
c.disabled = true;
}
To unlock:
var controls = document.querySelectorAll("button, input, select, textarea");
for (var c of controls) {
c.disabled = false;
}
That simple.

Just and without crutches!
/**
* Enable/disable all form controlls
* #param status Status: true - form active, false - form unactive
*/
HTMLFormElement.prototype.setStatus = function (status) {
for (var i in this.elements) {
this.elements[i].disabled = !status;
}
};
// Example:
var my_form = document.getElementById('my_form_with_many_inputs');
my_form.setStatus(false); // Disable all inputs in form
my_form.setStatus(true); // Enable all inputs in form

Depending what result you need you could also do
`document.getElementById('main_form').style.display = 'none';`
Where main_form is the id of your form. You can use the same technique to hide a div containing whatever elements you want to disable.

The best way is to add a div with highest z-index having width:100% and height:100%.It will cover your entire page and make everything not clickable means disabled virtually.It is best,because it will not use any loop and any complex code.