Javascript does not write innerHTML of element but flashes result? - javascript

In this simple program, the script does not write result id="result" just flashes the resultant value. Can anybody take a look and show why this behavior? What am I doing wrong?
function multiplication() {
var product,
no1 = document.getElementById('no1').value,
no2 = document.getElementById('no2').value;
product = no1 * no2;
document.getElementById("result").innerHTML = product;
}
function division() {
var divis,
no1 = document.getElementById('no1').value,
no2 = document.getElementById('no2').value;
divis = no1 / no2;
document.getElementById("result").innerHTML = divis;
}
<h2>Write a JavaScript program to calculate multiplication and division of two numbers ?</h2>
<h3>Sample Form</h3>
<form name="sample" method="POST">
1st Number:
<input type="text" id="no1" name="firstno" /> 2nd Number:
<input type="text" id="no2" name="secondno" />
<button id="mul" onclick="multiplication();">Multiply</button>
<button id="div" onclick="division();">Division</button>
</form>
<p id="result"></p>

The submit button is clicked
The JavaScript runs
The form is submitted
A new page is loaded
The new page doesn't have the DOM changes that were on the old page.
Either prevent the default behaviour of the submit button or bind your event handler to a different kind of control.

Your JS is working but when the user clicks a submit button the form is also submitted, because that's the default action.
Prevent the form from submitting.
<form onsubmit="event.preventDefault();" name="sample" method="POST">

<button type="button" id="mul" onclick="multiplication();">Multiply</button>
<button type="button" id="div" onclick="division();">Division</button>
This might help you.

Related

Form Submit with JS Not Posting to Controller

I would like to 'post' a form with vanilla JS. There are other questions similar, but I cannot get mine to work. The data is simply not passing to the controller.
I have several options for user on page, displayed as buttons. When the user clicks one button, a hidden form gets filled, and then the JS will submit the form to the controller.
the hidden form below:
[for testing, I have not 'hidden' the form fields yet, so I can monitor the correct information is getting to the form]
<form action="RetailTimePriceDisplayOne" method="post" id="postForm" name="postForm">
<input type="text" id="fmZero" value="#ViewBag.zero" />
<input type="text" id="fmVehicle" />
<input type="text" id="fmTeam" />
<input type="text" id="fmTLabor" />
<input type="text" id="fmRouteCost" />
<input type="text" id="fmRouteD" value="#ViewBag.vehicleMile"/>
<input type="text" id="fmRouteT" value="#ViewBag.vehicleTime"/>
</form>
My JS:
<script>
function fillForm(vehicleType, teamCount, travelLabor, routeCost) {
document.getElementById("fmVehicle").value = vehicleType;
document.getElementById("fmTeam").value = teamCount;
var x = #ViewBag.rateTravelDrvr;
if (teamCount > 1) {
x = #ViewBag.rateTravelDrvr + (#ViewBag.rateTravelCrew * (teamCount - 1));
}
document.getElementById("fmTLabor").value = x;
var y;
if (vehicleType == "V") {
y = #ViewBag.vVPrice;
}
if (vehicleType == "H") {
y = #ViewBag.vHPrice;
}
if (vehicleType == "T") {
y = #ViewBag.vTPrice;
}
document.getElementById("fmRouteCost").value = y;
SubmitForm();
}
function SubmitForm() {
var myForm = document.getElementById('postForm');
//document.forms["postForm"].submit();
myForm.method = 'post';
myForm.submit();
}
</script>
The form gets filled correctly, but no data is submitted to the controller. You can see that I played around with it a bit. One thought I had was that the method was changing to 'get' and that by explicitly specifying the method, I might solve the issue. But no such luck. Thanks!
EDIT:
As requested, one of the 6 buttons on the page that fire the JS function.
<button class="btn btn-secondary btn-lg" style="width:100%; height:100%;" onclick="fillForm('T',3)">
<strong>#ViewBag.TrkThr</strong>
<p>with 3 persons</p>
<p>+ #ViewBag.TrkMinute per labor minute*</p>
</button>
Usually when I want to submit the form, I am using button, then do onClick event
The "name" of the inputs wasn't defined, and hence data wasn't getting posted.

Reset for form not working after search has been done

I am trying to reset the form to blank values in the input textboxes after the data filled in the textbox have been searched.
<form id="myForm" class="mt-5" asp-controller="Leave" asp-action="GetAllLeaves">
<div class="form group col-md-6">
<label>Employee </label>
<div class="col">
<input type="hidden" id="employeeId" name="employeeId" />
<input type="text" name="employeeName" id="employeeName" value="#ViewData["CurrentFilterE"]" />
</div>
</div>
<button type="submit" class="btn btn-outline-success">Search</button>
<button type="reset" id="reset" class="btn btn-outline-primary">Reset</button>
</form>
I have tried bunch of different javascripts but none of them work after the search has been completed. They work fine before the search button is clicked. I am aware that there are questions already asked about this here and I have tried those codes but they don't work for me.
These are the different codes that I have tried. They don't work after the search button has been hit. Even refreshing the page does not delete the data in the input boxes.
function myFunction() {
document.getElementById("myForm")[0].reset();
};
$("#reset").click(function () {
$(this).closest('form').find("input[type=text], textarea").val("");
});
document.getElementById("reset").onclick = () => {
document.getElementById("myForm").reset()
};
let inputs = document.querySelectorAll('input');
document.getElementById("reset").onclick = () => {
inputs.forEach(input => input.value ='');
}
in your post method you need to have an IactionResult return type method and then you need to pass property name to ModelState.Remove method, not the value.
Either pass the property name in string, eg. ModelState.Remove("PropertyName"); or in the newer .NET framework, you can use nameof() keyword, eg. ModelState.Remove(nameof(model.Property));
The HTMLFormElement.reset() method restores a form element's default values. This method does the same thing as clicking the form's reset button. If a form control (such as a reset button) has a name or id of reset it will mask the form's reset method. It does not reset other attributes in the input, such as disabled.
https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/reset.
Your default input value = "#ViewData["CurrentFilterE"]". Reset method restores a form element's default values.
This will help to reset the input:
html:
<form id="myForm">
<input type="text" name="employeeName" id="employeeName" value="test" />
<button id="reset" class="btn btn-outline-primary">Reset</button>
</form>
js:
document.getElementById("reset").onclick = function(e) {
document.getElementById("employeeName").value = "";
}
I ended up using the following
$("#reset").click(function () {
// this for normal <input> text box
$('#employeeName').attr("value", "");
//this for checkbox
document.getElementById('searchAprroved').removeAttribute('checked');
});

Javascript: avoiding window to reload

I have this form, that is never submitted: it just triggers a calcularplazas() function when pressing a non-submit button:
<form name="what" id="what" action="">
<input id="mat" type="text"/>
<button id="btnEnviar" class="btn" onclick="calcularplazas();">SEND</button>
<input id="btnLimpiar" class="btn" type="reset" value="CLEAR" />
<p id="resultado"></p>
</form>
When clicking on the button, function works properly but no result can be shown, as the window reloads. I do not understand this behaviour as there's nothing on the function making it reload, neither is a form submitting.
As consequence of this, the result text is exported to <p id="resultado"></p> but on miliseconds dissapears, as window reloads.
Why this behaviour?
function calcularplazas(){
var mensaje = "MENSAJE FINAL";
document.getElementById("resultado").innerHTML = mensaje;
}
You say "non-submit" button, but since you haven't given your <button> element a type attribute, it is a submit button by default. You need to tell the browser to treat it as a "normal" button:
<button type="button" id="btnEnviar" class="btn" onclick="calcularplazas();">SEND</button>
Clicking this will now not submit the form, and not cause the page to reload.
You can prevent submit event to be dispatched.
myForm.addEventListener('submit', function(e) {
e.preventDefault();
calcularplazas();
// do anything else you want
})
And HTML
<form id="myForm">
<input id="input1" type="text"/>
<button type="submit" id="myButton">SEND</button>
</form>
It will works for Return key to do as well
The button in the form, have you tried giving it type="button" ?
Because in a form it gets type="submit" by default (or the form behaves like it would with a submit type).
You Need to make only 2 changes and the code will run .
Put return false in the javascript function.
when you call the function on onclick function write return calcularplazas.
check the below code for for your reference.
function calcularplazas(){
var mensaje = "MENSAJE FINAL";
document.getElementById("resultado").innerHTML = mensaje;
return false;
}
<button id="btnEnviar" class="btn" onclick="return calcularplazas();">SEND</button>

AJAX and submit button on form interaction

I'm creating a simple website and a html page on it which contains a table that shows products. I load this table using AJAX and it work properly. Here is a screenshot:
Under the table I have buttons which perform CRUD operations using AJAX.
They communicate to a php script on a server outside of my domain using GET method.
When I click on Add product it opens a form with a button that whose onclick event calls a function which adds a product using AJAX. But, when I click, the whole page reloads and the product is not added. If I put the value that says wheter the call is async to false, it works as intended and the product is added to the table, however that is not the point of AJAX.
This is my code for adding a product(delete and update are almost the same).
<div id="addProductPopup">
<div id="popupContact">
<form id="form" method="post" name="form">
<img id="close" src="/servis/Resursi/Slike/close.png" onclick ="hide('addProductPopup');">
<h2>Dodavanje proizvoda</h2>
<hr>
<input id="name" name="naziv" placeholder="Naziv proizvoda" type="text" required>
<input id="kolicina" name="kolicina" placeholder="Količina proizvoda" type="text" required>
<input id="url" name="url" placeholder="URL slike" type="text" required>
<input type="submit" value="Pošalji" class="popupButtons" onclick="addProduct()">
</form>
</div>
When I click on submit this function is called:
function addProduct(){
var isValid = true;
var url = "http://zamger.etf.unsa.ba/wt/proizvodi.php?brindexa=16390";
var amount = document.form.kolicina.value;
var naziv = document.form.naziv.value;
var slikaurl = document.form.url.value;
var validity = validateFields(naziv, slikaurl, amount);
if(!validity) return false;
var product = {
naziv: naziv,
kolicina: amount,
slika: slikaurl
};
var requestObject = new XMLHttpRequest();
requestObject.onreadystatechange = function(event) {
if (requestObject.readyState == 4 && requestObject.status == 200)
{
loadProducts();
event.preventDefault();
}
}
requestObject.open("POST", url, true);
requestObject.setRequestHeader("Content-type","application/x-www-form-urlencoded");
requestObject.send("akcija=dodavanje" + "&brindexa=16390&proizvod=" + JSON.stringify(product));
}
It is because you are not preventing the default action of the submit button click.
You can return false from an event handler to prevent the default action of an event so
<input type="submit" value="Pošalji" class="popupButtons" onclick="addProduct(); return false;">
But since you have a form with a submit button, I think it will be better to use the submit event handler like
<form id="form" method="post" name="form" onsubmit="addProduct(); return false;">
....
<input type="submit" value="Pošalji" class="popupButtons">
Your problem is that your submit button still executes a real submit. You could change your addProducts method. The method have to return false to prevent the real submit.
Submit button performs default Submit action for HTML code.
Try to change Submit tag into Button tag. Or after AddProduct() in OnClick JS Action put
return false;
Simple Change put input type="button" instead of tpye="submit"
<input type="button" value="Pošalji" class="popupButtons" onclick="addProduct()">

innerHTML won't change element

I have an div element ("main") on my page who's contents changes back and forth between two different screens (their id's are "readout" and "num"), the contents of which are stored as hidden div elements (using display:none). Each screen has a button which sets mainto the other hidden div.
Since I struggled to get javascript to put num.innerHTML into main on load, I've ended up putting virtually identical content to num (with a different form name) into main:
<p>Number of Passengers per Carriage:</p>
<form method="post" action="javascript:void(0);" name="applesForm" onSubmit="setPassengers();">
<input type="text" name="numApples" id="numPassengers" />
<br/><br/>
<input type="submit" name="Submit" value="OK!"/>
</form>
setPassengers() successfully sets main's contents to readout. readout successfully sets main's contents to num (virtually identical to the original content of main). But then it won't go back to readout.
Here are setPassengers() and setPassengersAgain(), which is the same but for a different form name:
function setPassengers()
{
passengers=document.applesForm.numPassengers.value;
document.getElementById('main').innerHTML=readout.innerHTML;
}
function setPassengersAgain()
{
passengers=document.applesFormAgain.numPassengers.value;
document.getElementById('main').innerHTML=readout.innerHTML;
}
So my question is:
1)Why isn't num changing to readout?
2)Is there a way to load num straight away on page load so as to simplify the code?
EDIT: I can use onload, which means that num is the only bit that's broken...
EDIT 2: Here are the hidden div's:
<div id="readout" style="display:none">
<p>Throughput per hour:</p>
<p id="output">--</p>
<p>Average Dispatch Time:</p>
<p id="avDisTime">--</p>
<form method="post" action="javascript:void(0);" name="dispatchForm" onSubmit="dispatch();i++;">
<input type="submit" name="Submit" value="Press on Dispatch!"/>
</form>
<br/>
<form method="post" action="javascript:void(0);" name="resetTimesForm" onSubmit="resetTimes();">
<input type="submit" name="Submit" value="Reset Times"/>
</form>
<form method="post" action="javascript:void(0);" name="resetAllForm" onSubmit="resetAll();">
<input type="submit" name="Submit" value="Reset All"/>
</form>
</div>
<!--back to default page-->
<div id="num" style="display:none">
<p>Number of Passengers per Carriage:</p>
<form method="post" action="javascript:void(0);" name="applesFormAgain" onSubmit="setPassengersAgain();">
<input type="text" name="numApples" id="numPassengers" />
<br/><br/>
<input type="submit" name="Submit" value="OK!"/>
</form>
</div>
You didn't post your HTML code, so I don't know how it looks like, but you could use somethin like:
HTML:
<button id="changeMain">Change #main</button>
<div id="main">
<div id="readout" class="screen show">
Readout
</div>
<div id="num" class="screen">
Num
</div>
</div>
CSS:
#main>.screen{display:none;}
#main>.screen.show{display:block;}
JavaScript:
var els=[document.getElementById('readout'),document.getElementById('num')],current;
function addClass(el,c){
var arr=el.className.split(' ');
if(arr.indexOf(c)>-1){return;}
arr.push(c);
el.className=arr.join(' ');
}
function delClass(el,c){
var arr=el.className.split(' ');
var i=arr.indexOf(c);
if(i===-1){return;}
arr.splice(i,1);
el.className=arr.join(' ');
}
document.getElementById('changeMain').onclick=function(){
if(!current){
for(var i=0,l=els.length;i<l;i++){
if(els[i].className.indexOf('show')>-1){
current=i;
break;
}
}
}
delClass(els[current],'show');
current=(current+1)%els.length;
addClass(els[current],'show');
}
DEMO: http://jsfiddle.net/CUgqh/
Explanation:
If you want some content insode #main, you should place inside it (hidden or shown). Then, we hide all .screen with #main>.screen{display:none;} except .screen.show: #main>.screen.show{display:block;}.
Then, JavaScript code:
First we create an array with the elements:
var els=[document.getElementById('readout'),document.getElementById('num')],current;
And a function which adds/removes a class c to the element el:
function addClass(el,c){
var arr=el.className.split(' ');
if(arr.indexOf(c)>-1){return;}
arr.push(c);
el.className=arr.join(' ');
}
function delClass(el,c){
var arr=el.className.split(' ');
var i=arr.indexOf(c);
if(i===-1){return;}
arr.splice(i,1);
el.className=arr.join(' ');
}
And we create an event to the button:
document.getElementById('changeMain').onclick=function(){
if(!current){
for(var i=0,l=els.length;i<l;i++){
if(els[i].className.indexOf('show')>-1){
current=i;
break;
}
}
}
delClass(els[current],'show');
current=(current+1)%els.length;
addClass(els[current],'show');
}
The code above does:
If it's the first time the current els' index (current) is undefined, we search which element has the class show by default.
It removes the class show to the current shown element, so it disappears.
It adds 1 to current (or it becomes 0 if it was the last els' element
It add class show to the current element, so it appears.

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