Develop Reference

JS - Add class to form when input has value

I have a form with one input field for the emailaddress. Now I want to add a class to the <form> when the input has value, but I can't figure out how to do that.
I'm using this code to add a class to the label when the input has value, but I can't make it work for the also:
function checkForInputFooter(element) {
const $label = $(element).siblings('.raven-field-label');
if ($(element).val().length > 0) {
$label.addClass('input-has-value');
} else {
$label.removeClass('input-has-value');
}
}
// The lines below are executed on page load
$('input.raven-field').each(function() {
checkForInputFooter(this);
});
// The lines below (inside) are executed on change & keyup
$('input.raven-field').on('change keyup', function() {
checkForInputFooter(this);
});
Pen: https://codepen.io/mdia/pen/gOrOWMN

This is the solution using jQuery:
function checkForInputFooter(element) {
// element is passed to the function ^
const $label = $(element).siblings('.raven-field-label');
var $element = $(element);
if ($element.val().length > 0) {
$label.addClass('input-has-value');
$element.closest('form').addClass('input-has-value');
} else {
$label.removeClass('input-has-value');
$element.closest('form').removeClass('input-has-value');
}
}
// The lines below are executed on page load
$('input.raven-field').each(function() {
checkForInputFooter(this);
});
// The lines below (inside) are executed on change & keyup
$('input.raven-field').on('change keyup', function() {
checkForInputFooter(this);
});
I've updated your pen here.

Here it is, using javascript vanilla. I selected the label tag ad form tag and added/removed the class accoring to the element value, but first you should add id="myForm" to your form html tag. Good luck.
function checkForInputFooter(element) {
// element is passed to the function ^
let label = element.parentNode.querySelector('.raven-field-label');
let myForm = document.getElementById("myform");
let inputValue = element.value;
if(inputValue != "" && inputValue != null){
label.classList.add('input-has-value');
myForm.classList.add('input-has-value');
}
else{
label.classList.remove('input-has-value');
myForm.classList.remove('input-has-value');
}
}

You can listen to the 'input' event of the input element and use .closest(<selector>) to add or remove the class
$('input').on('input', function () {
if (!this.value) {
$(this).closest('form').removeClass('has-value');
} else {
$(this).closest('form').addClass('has-value');
}
})
Edit: https://codepen.io/KlumperN/pen/xxVxdzy

A button should show/hide depending on whether or not there is value in input field

Right now the button shows when input is added to the input field, but if I remove the input the button doesn't hide.
My only idea for a solution is to divide the function into 2 seperate ones.
That is, one that adds the input to the input field on click, and then another functions that keeps track of input.val, and controls the hide/show effect of the button.
Would that be a better way of doing it?
$("#peopleInPopup").on('click', '.list-group-item', function() {
var peopleName = $(this).children("span").text();
var peopleID = $(this).children("span").attr("class");
var input = $("#friendsNames");
input.val(input.val() + peopleName + "");
if (input.val().length === 0) {
$("#checkButton").toggle(false);
console.log("button should NOT display");
} else {
console.log("button should display");
$("#checkButton").toggle(true);
}
$("#checkButton").click(function() {
var newParticipants = input.val();
socket.emit("addParticipantsToConversation", newParticipants);
$("#chatToInfo").append(", ", input.val());
$("#friendsNames").val("");
$(":mobile-pagecontainer").pagecontainer("change", $("#pagefour"), {
transition: "slidedown"
});
});
});

Just use show and hide from jQuery instead, perhaps? I assume you want this to happen as the input is changing, so I've thrown in keyup (could use onChange or alternatives).
Tweaking your code slightly...
$('input').on('keyup', function (event) {
let value = event.target.value;
if (value && value !== '' && value.length > 0) {
$('#myButton').show();
} else {
$('#myButton').hide();
}
})
With a markup...
<input id='input' />
<button id='myButton'>GO</button>
And some sort of base style...
#go {
display: none;
}
Do the trick?

I actually just found a solution to my problem. The code below makes it work:
$("#peopleInPopup").on('click', '.list-group-item', function(){
var peopleName = $(this).children("span").text();
var peopleID = $(this).children("span").attr("class");
var input = $("#friendsNames");
input.val(input.val() + peopleName + "");
$("#checkButton").toggle(true);
$("#friendsNames").on('input', function(event) {
if (this.value.length === 0) {
console.log("Works!");
$("#checkButton").toggle(false);
console.log("button should NOT display");
} else {
console.log("button should display");
$("#checkButton").toggle(true);
}
});
$("#checkButton").click(function(){
var newParticipants = input.val();
socket.emit("addParticipantsToConversation", newParticipants);
$("#chatToInfo").append(", ",input.val());
$("#friendsNames").val("");
$(":mobile-pagecontainer").pagecontainer("change", $("#pagefour"), { transition: "slidedown" });
});
});

Keyup event handler shows slow performance

My example:
$(document).on('keyup', '[contenteditable=true]', function (e) {
let _this = $(this), text = _this.text();
if (text.length === 1) {
let span = $('<span>').text(text);
_this.html(span);
}
console.log(_this.html());
});
[contenteditable=true] {
border: 1px solid #ccc;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div contenteditable="true"></div>
My problem: If I type some text (more than 1 character) with normal speed into the div, code works fine. But, when I try to type text with fast speed, no <span> tag was appended to the div.
How can I fix that?

You could use input event instead it's more efficient when you trach user inputs, check example below :
$(document).on('input', '[contenteditable=true]', function (e) {
//Your logic
});
Or also keypress as T.J. Crowder comment's says :
$(document).on('keypress', '[contenteditable=true]', function (e) {
//Your logic
});
Hope this helps.
$(document).on('input', '[contenteditable=true]', function (e) {
let _this = $(this), text = _this.text();
if (text.length === 1) {
let span = $('<span>').text(text);
_this.html(span);
}
console.log(_this.html());
});
[contenteditable=true] {
border: 1px solid #ccc;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div contenteditable="true"></div>

Input unresolved quest

I have this code:
http://jsfiddle.net/4Qsa8/111/
This input is increasing size when you type a letter as you can see. But here is the issue, when I delete first letter from the end, the input does not decrease, it starts to decrease when I delete the second letter from the end. So the question is how to make input decrease in size on the deleting of the last letter, not on the second, before thanks.
-HTML
<div class="resizing-input">
* <input type="text" placeholder="placeholder"/>
<span style="display:none"></span>
</div>
-CSS
.resizing-input input, .resizing-input span {
font-size: 20px;
font-family: Sans-serif;
white-space: pre;
padding: 1px;
}
-JS
$(document).ready(function () {
var $inputs = $('.resizing-input');
// Resize based on text if text.length > 0
// Otherwise resize based on the placeholder
function resizeForText(text) {
var $this = $(this);
if (!text.trim()) {
text = $this.attr('placeholder').trim();
}
var $span = $this.parent().find('span');
$span.text(text);
var $inputSize = $span.width();
$this.css("width", $inputSize);
}
$inputs.find('input').keypress(function (e) {
if (e.which && e.charCode) {
var c = String.fromCharCode(e.keyCode | e.charCode);
var $this = $(this);
resizeForText.call($this, $this.val() + c);
}
});
// Backspace event only fires for keyup
$inputs.find('input').keydown(function (e) {
if (e.keyCode === 8 || e.keyCode === 46) {
resizeForText.call($(this), $(this).val());
}
});
$inputs.find('input').each(function () {
var $this = $(this);
resizeForText.call($this, $this.val())
});
});

Use keyup event instead of keydown event. because keydown event occurs before the input update its value. It will work.

Line 26 of the jsfiddle example, change the line:
$inputs.find('input').keydown(function (e) {
to:
$inputs.find('input').keyup(function (e) {

Need to simulate keypress jquery

I have a function that uses the value of a textbox (prodinput) to hide/show links in a dropdown list. It works when a user types in a string manually but when I want to auto-populate the value by passing a url parameter I'll need to trigger a keyup or keydown to get it to call the function.
Here is the function that does the search (located in the core.js):
prodinput.on('keyup, keydown',function() {
var search = $(this).val().toLowerCase();
$('.support-product .browse-products a').each(function() {
if($(this).text().toLowerCase().search(search) > -1) {
$(this).parent().show();
} else {
$(this).parent().hide();
}
});
});
Here is the function I'm using to trigger the function above (located on the page I'm trying to run it on.
$(function(){
$target = $('.browse-products .display');
$target.val($trimmed);
$('.browse-products').addClass('active');
$target.focus();
var e = jQuery.Event( "keydown" );
$target.trigger(e);
});
I've tried using:
$target.keyup();
and as shown above:
var e = jQuery.Event( "keydown" );
$target.trigger(e);
I'm wondering if it's a problem with the order in which things load on the page.

I'd put your keyup code in a named function.
$(function () {
myFunction();
prodinput.on('keyup, keydown', function () {
myFunction();
})
};
var myFunction = function () {
var search = $('#prodinput').val().toLowerCase();
$('.support-product .browse-products a').each(function () {
if ($(this).text().toLowerCase().search(search) > -1) {
$(this).parent().show();
} else {
$(this).parent().hide();
}
});
};

Assuming you don't need to support ancient browsers you can just listen for the input event which covers keypress and change events. Then after attaching the listener simply trigger the event:
$(function() {
$("#prodinput").on('input', function() {//alternatively you could use change and keyup
var search = $(this).val().toLowerCase();
$('.support-product .browse-products a').each(function() {
if ($(this).text().toLowerCase().search(search) > -1) {
$(this).parent().show();
} else {
$(this).parent().hide();
}
});
}).trigger("input");//trigger the event now
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="search" id="prodinput" value="peanuts" />
<div class="support-product">
<ul class="browse-products">
<li>jam</li>
<li>elephants</li>
<li>peanuts</li>
</ul>
</div>