Develop Reference

Change checkbox checked with JavaScript

I am trying to change a part of my html code with JavaScript, but I can't get it to work:
function trigger(){
document.getElementById('mycheckbox').innerHTML="<input type="checkbox" id="mycheckbox" checked>";
}
function triggerOff(){
document.getElementById('mycheckbox').innerHTML="<input type="checkbox" id="mycheckbox">";
}
<input type="checkbox" id="mycheckbox">
<button type="button" onclick="trigger()">test</button>
<button type="button" onclick="triggerOff()">test</button>
So if I press the button I want to add the checked status to my HTML and if I press the other button I want to remove the checked status.
Is this even possible?
All help is highly appreciated ! Thanks a lot guys!

You cannot set innerHTML to input type checkbox. Use the checked property to check/uncheck the checkbox
function trigger(){
document.getElementById('mycheckbox').checked = true;
}
function triggerOff(){
document.getElementById('mycheckbox').checked = false;
}
<input type="checkbox" id="mycheckbox">
<button type="button" onclick="trigger()">test</button>
<button type="button" onclick="triggerOff()">test</button>

Use checked property, like this:
function trigger(){
document.getElementById('mycheckbox').checked=true;
}
function triggerOff(){
document.getElementById('mycheckbox').checked=false;
}
<input type="checkbox" id="mycheckbox">
<button type="button" onclick="trigger()">test</button>
<button type="button" onclick="triggerOff()">test</button>

Just do it like that
function trigger(){
document.getElementById('mycheckbox').checked = true;
}
function triggerOff(){
document.getElementById('mycheckbox').checked = false;
}
The innerHTML property will create inside your mycheckbox another input element

Add input to form if button is clilcked

I'm not really sure the best way to go about this but I've laid the framework.
Basically, I would like to add the functionality so that when my #moreItems_add button is clicked and calls the moreItems function, I simply want to add a new Input field below it, and so on. I want to limit this to 10 fields though, so I show that in the function.
The only trick is, I will be submitting all fields via ajax to save to the database, so I need to try and keep track of an ID with each.
What's the best way to continue the javascript here so that I can append an input field on button press and keep track of IDs for each?
<div class="modal-body">
<form id="Items">
<label id="ItemLabel">Item 1:</label>
<input type="text" name="Items[]">
<button id="moreItems_add" onclick="moreItems()" id="moreItems">More Items</button>
</form>
</div>
<div class="modal-footer">
<input type="submit" name="saveItems" value="Save Items">
</div>
<!-- modal JS -->
<script type="text/javascript">
function moreItems(){
var MaxItems = 10;
//If less than 10, add another input field
}
</script>

You can use the jQuery .insertBefore() method to insert elements right before "more items" button. Below is the code representing this:
var maxItems = 1;
function moreItems() {
if (maxItems < 10) {
var label = document.createElement("label");
label.id="ItemLabel"+maxItems;
label.innerHTML = "Item "+(maxItems+1)+": ";
var input = document.createElement("input");
input.type='text';
input.name = 'item'+maxItems;
$('<br/>').insertBefore("#moreItems_add");
$(label).insertBefore("#moreItems_add");
$(input).insertBefore("#moreItems_add");
maxItems++;
}
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="modal-body">
<form id="Items">
<label id="ItemLabel">Item 1:</label>
<input type="text" name="Items[]">
<button type="button" id="moreItems_add" onclick="moreItems()" id="moreItems">More Items</button>
</form>
</div>
<div class="modal-footer">
<input type="submit" name="saveItems" value="Save Items">
</div>

Something like this should do the trick:
<!-- modal JS -->
<script type="text/javascript">
var MAX_ITEMS = 10,
added = 0;
function moreItems(){
if (added >= MAX_ITEMS) return;
var newField = document.createElement('input');
newField.type = 'text';
// TODO: Any field setup.
document.getElementById('items').appendChild(newField);
added++;
}
</script>
In terms of tracking each field with an ID, that should always be done by the back-end for data integrity and safety reasons.

some years ago I've wrote an article about making a repeated section using jQuery.
The live example is available on jsFiddle.
In the example you can find that both "add" and "remove" button are available, however you can set just the "add" button for your purpose.
The idea to limit to specific number of repeated boxes is to watch the number of repeatable elements just created in the context. The part of code to change in the live example is rows 13-18:
// Cloning the container with events
var clonedSection = $(theContainer).clone(true);
// And appending it just after the current container
$(clonedSection).insertAfter(theContainer);
There you should check if the number of repeated elements is less than <your desired number> then you will allow the item to be created, else you can do something else (like notice the user about limit reached).

Try this:
const maxItens = 10,
let itensCount = 0;
function moreItems() {
if (itensCount++ >= maxItens) {
return false;
}
let newInput = document.createElement('input');
// use the iterator to make an unique id and name (to submit multiples)
newInput.id = `Items[${itensCount}]`;
newInput.name = `Items[${itensCount}]`;
document.getElementById('items').appendChild(newInput);
return false;
}
Add type "button" to stop submiting the page (also, your button have two ID):
<button id="moreItems_add" onclick="moreItems();" type="button">More Items</button>
The submit button must be inside the form to work:
<form>
<div class="modal-body">
<div id="Items">
<label id="ItemLabel">Item 1:</label>
<input type="text" name="Items[]">
</div>
<button id="moreItems_add" onclick="moreItems()" id="moreItems">More Items</button>
</div>
<div class="modal-footer">
<button type="submit">Save Items</button>
</div>
</form>
To append itens in sequence the button must be outside of div "itens".

is it possible to have a checkbox control two button state

i have a form with two buttons and a checkbox, i want when user checks the checkbox one of the button is enabled while the other button is disabled. So when the forms loads one will be enable by default and the other disabled, but after the checkbox has been checked the other becomes enabled while that which was enable by default become disabled..
i can actually do this for one button but i can do this for two button, please can someone with javascript skills help me out here thanks.

You could do this with JQuery. Try the snippet below:
$('document').ready(function() {
$('.checkbox_check').change(function() {
var isChecked = $('.checkbox_check').is(':checked');
$('#btn1').prop('disabled', !isChecked);
$('#btn2').prop('disabled', isChecked);
});
})
<button type="button" id='btn1' disabled>Button 1</button>
<button type="button" id='btn2'>Button 2</button>
<input type="checkbox" class='checkbox_check' />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Update:
Per the comment below, here's a Vanilla JS solution:
function toggleDisabled() {
var isChecked = document.getElementById("checkbox_check").checked;
document.getElementById('btn1').disabled = !isChecked;
document.getElementById('btn2').disabled = isChecked;
}
<button type="button" id="btn1" disabled>Button 1</button>
<button type="button" id="btn2">Button 2</button>
<input type="checkbox" id="checkbox_check" onChange="toggleDisabled()" />

You can achieve this with Vanilla JS
function fireChange() {
const button1 = document.getElementById('test1');
const button2 = document.getElementById('test2');
button1.disabled = !button1.disabled;
button2.disabled = !button2.disabled;
}
<button disabled id="test1"> first button </button>
<button id="test2"> second button </button>
<input type="checkbox" onChange="fireChange()" />

Hide form on submit with Angular JS

Trying to wrap my head around some Angular items and working thru a tutorial to edit and learn.
Clicking the below button shows the below form. How do I reverse this once the form is submitted? Meaning hiding the form on submit until the button is clicked once more.
<button ng-click="addNewClicked=!addNewClicked;" class="btn btn-sm btn-primary">
<i class="fa fa-plus"></i>Add Task
</button>
Basically, the form appears, I enter something and submit, but would like the form to dissapear upon submit? Thinking something to do with ng-hide, but can I do this using only Angular? Or do I need to do something with javascript/css?
<div id="addForm" class="margin-full-5">
<form ng-init="addNewClicked=false; " ng-if="addNewClicked" id="newTaskForm" class="add-task">
<div class="form-actions">
<div class="input-group">
<input type="text" class="form-control" name="comment" ng-model="taskInput" placeholder="Add New Task" ng-focus="addNewClicked">
<div class="input-group-btn">
<button class="btn btn-default" type="submit" ng-click="addTask(taskInput)">
<i class="fa fa-plus"></i> Add Task
</button>
</div>
</div>
</div>
</form>

You can also achieve this using a combination of Angular form's attribute $submitted, ng-hide and ng-submit
<form name="myForm" ng-hide="myForm.$submitted" ng-submit="submit()">
<button>Submit</button>
</form>
Read about it here: https://docs.angularjs.org/api/ng/type/form.FormController

Somewhere in your view.
<button ng-click="showTheForm = !showTheForm">Add a Task</button>
<form ng-show="showTheForm" ng-submit="processForm()">
<button>Submit</button>
<button type="button" ng-click="showTheForm = false">Cancel</button>
</form>
Somewhere in your controller
$scope.processForm = function() {
// execute something
$scope.showTheForm = false;
}

Your form is displaying IF the addNewClicked value evaluates to true, which occurs when you click the add task button. If you want the form to disappear on submit, you just need to make the onClick to that button change your addNewClicked to false.
AngularJS Docs for Ng-If

You can do that by using ng-show/ng-hide as per example below :
<form ng-init="addNewClicked=false; " ng-if="addNewClicked" ng-hide="hideform" id="newTaskForm" class="add-task">
and modify the submit method to make the hideform = true;
$scope.addTask = function(input){
... your things
$scope.hideform = true;
}
You can also do the same using jQuery :
$("#newTaskForm").hide();

This should do the trick:
$scope.addTask = function(taskInput) {
...
$scope.addNewClicked = false;
}

You could use ng-show as you can see in this jsfiddle
This will show and hide the div element based on clicking the button. When the button is clicked it will toggle the boolean, hence acting as an on/off switch for ng-show

Show/hide forms using buttons and JavaScript

I need to show a form using a button, and hide it when the user presses another button, because the other button shows another form. I did a similar thing with a select box, but I can't figure out how to do this.

Use the following code fragment to hide the form on button click.
document.getElementById("your form id").style.display="none";
And the following code to display it:
document.getElementById("your form id").style.display="block";
Or you can use the same function for both purposes:
function asd(a)
{
if(a==1)
document.getElementById("asd").style.display="none";
else
document.getElementById("asd").style.display="block";
}
And the HTML:
<form id="asd">form </form>
<button onclick="asd(1)">Hide</button>
<button onclick="asd(2)">Show</button>

There's something I bet you already heard about this! It's called jQuery.
$("#button1").click(function() {
$("#form1").show();
};
It's really easy and you can use CSS-like selectors and you can add animations. It's really easy to learn.

If you have a container and two sub containers, you can do like this
jQuery
$("#previousbutton").click(function() {
$("#form_sub_container1").show();
$("#form_sub_container2").hide(); })
$("#nextbutton").click(function() {
$("#form_container").find(":hidden").show().next();
$("#form_sub_container1").hide();
})
HTML
<div id="form_container">
<div id="form_sub_container1" style="display: block;">
</div>
<div id="form_sub_container2" style="display: none;">
</div>
</div>

There's the global attribute called hidden. But I'm green to all this and maybe there was a reason it wasn't mentioned yet?
var someCondition = true;
if (someCondition == true){
document.getElementById('hidden div').hidden = false;
}
<div id="hidden div" hidden>
stuff hidden by default
</div>
https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/hidden

Would you want the same form with different parts, showing each part accordingly with a button?
Here an example with three steps, that is, three form parts, but it is expandable to any number of form parts. The HTML characters « and » just print respectively « and » which might be interesting for the previous and next button characters.
shows_form_part(1)
/* this function shows form part [n] and hides the remaining form parts */
function shows_form_part(n){
var i = 1, p = document.getElementById("form_part"+1);
while (p !== null){
if (i === n){
p.style.display = "";
}
else{
p.style.display = "none";
}
i++;
p = document.getElementById("form_part"+i);
}
}
/* this is called at the last step using info filled during the previous steps*/
function calc_sum() {
var sum =
parseInt(document.getElementById("num1").value) +
parseInt(document.getElementById("num2").value) +
parseInt(document.getElementById("num3").value);
alert("The sum is: " + sum);
}
<div id="form_part1">
Part 1<br>
<input type="number" value="1" id="num1"><br>
<button type="button" onclick="shows_form_part(2)">»</button>
</div>
<div id="form_part2">
Part 2<br>
<input type="number" value="2" id="num2"><br>
<button type="button" onclick="shows_form_part(1)">«</button>
<button type="button" onclick="shows_form_part(3)">»</button>
</div>
<div id="form_part3">
Part 3<br>
<input type="number" value="3" id="num3"><br>
<button type="button" onclick="shows_form_part(2)">«</button>
<button type="button" onclick="calc_sum()">Sum</button>
</div>