Below, I have a simple form that has 4 checkboxes acting as seats. What I am trying to do is when a visitor chooses, say, seat checkboxes with IDs A2 and A4, I want those IDs and their total value to be shown instantly after clicking inside a paragraph with which have a name called id="demo". When a button [Reserve Now] has been clicked, the total value should be assigned to a variable called $TotalCost.
How can I acplish this? Here's my code:
<!DOCTYPE html>
<html>
<body>
<h2>Please choose a seat to book</h2>
<form action="/action_page.php" method="post">
<input type="checkbox" name="vehicle" id="A1" value="$100">$100<br>
<input type="checkbox" name="vehicle" id="A2" value="$65"> $65<br>
<input type="checkbox" name="vehicle" id="A3" value="$55"> $55<br>
<input type="checkbox" name="vehicle" id="A4" value="$50"> $50<br>
<p id="demo">
Selected Seat(s)
<br>
<br>
Total: USD <input type="submit" value="Reserve Now">
</form>
</p>
<script>
document.getElementById("A1").addEventListener("click", displayCheck);
function displayCheck() {
document.getElementById("demo").innerHTML = ;
}
</script>
</body>
</html>
Below, I have a simple form that has 4 checkboxes acting as seats. What I am trying to do is when a visitor chooses, say, seat checkboxes with IDs A2 and A4, I want those IDs and their total value to be shown instantly after clicking inside a paragraph with which have a name called id="demo". When a button [Reserve Now] has been clicked, the total value should be assigned to a variable called $TotalCost.
How can I acplish this? Here's my code:
<!DOCTYPE html>
<html>
<body>
<h2>Please choose a seat to book</h2>
<form action="/action_page.php" method="post">
<input type="checkbox" name="vehicle" id="A1" value="$100">$100<br>
<input type="checkbox" name="vehicle" id="A2" value="$65"> $65<br>
<input type="checkbox" name="vehicle" id="A3" value="$55"> $55<br>
<input type="checkbox" name="vehicle" id="A4" value="$50"> $50<br>
<p id="demo">
Selected Seat(s)
<br>
<br>
Total: USD <input type="submit" value="Reserve Now">
</form>
</p>
<script>
document.getElementById("A1").addEventListener("click", displayCheck);
function displayCheck() {
document.getElementById("demo").innerHTML = ;
}
</script>
</body>
</html>
- Well, you probably don't want dollar signs in the values so you can perform math functions. – Devon Bessemer Commented Jul 19, 2018 at 23:43
- 2 That looks like an assignement where very few efforts were made. That's for tomorrow morning? – Louys Patrice Bessette Commented Jul 19, 2018 at 23:45
- @Devon: I think OP is far from server-side consideration about security. It's just a simple math addition that is expected here. – Louys Patrice Bessette Commented Jul 19, 2018 at 23:47
- See How to Ask, and especially minimal reproducible example. – user1531971 Commented Jul 20, 2018 at 3:58
- @LouysPatriceBessette No man its not an assignment. I am trying to get an idea in one of my bus seat reservation system i want to implement. – Wilson Commented Jul 20, 2018 at 13:23
2 Answers
Reset to default 10Here's one approach to setting up event listeners on checkboxes. I used document.querySelectorAll("input[type='checkbox']"); to fetch all of the checkbox elements from the DOM and a loop to add a listener to each checkbox. A selections object can keep track of which items have been checked. When a checkbox is clicked on, the item values are added to the object by key. When the checkbox is off, the item is deleted from the object. Whenever an action happens, the DOM is updated with all relevant information based on the contents of selections.
This example is just a quick sketch to give you the idea. You'll need another event listener for your submit button to handle sending the form data to your PHP script. I'll leave that as an exercise.
Note that the HTML you've provided is invalid because nesting is broken. A HTML validator can be helpful for fixing these sort of problems.
var selections = {};
var checkboxElems = document.querySelectorAll("input[type='checkbox']");
var totalElem = document.getElementById("seats-total");
var seatsElem = document.getElementById("selected-seats");
for (var i = 0; i < checkboxElems.length; i++) {
checkboxElems[i].addEventListener("click", displayCheck);
}
function displayCheck(e) {
if (e.target.checked) {
selections[e.target.id] = {
name: e.target.name,
value: e.target.value
};
}
else {
delete selections[e.target.id];
}
var result = [];
var total = 0;
for (var key in selections) {
var listItem = "<li>" + selections[key].name + " " +
selections[key].value + "</li>";
result.push(listItem);
total += parseInt(selections[key].value.substring(1));
}
totalElem.innerText = total;
seatsElem.innerHTML = result.join("");
}<!DOCTYPE html>
<html lang="en">
<head>
<title>...</title>
</head>
<body>
<h2>Please choose a seat to book</h2>
<form action="/action_page.php" method="post">
<input type="checkbox" name="vehicle" id="A1" value="$100">$100<br>
<input type="checkbox" name="vehicle" id="A2" value="$65"> $65<br>
<input type="checkbox" name="vehicle" id="A3" value="$55"> $55<br>
<input type="checkbox" name="vehicle" id="A4" value="$50"> $50<br>
<p>Selected Seat(s)</p>
<!-- container for displaying selected seats -->
<ul id="selected-seats"></ul>
<div>
Total: $<span id="seats-total">0</span> USD
<input type="submit" value="Reserve Now">
</div>
</form>
</body>
</html>Often, you'll want to generate the elements dynamically and add event listeners. Here's a toy example:
for (let i = 0; i < 1000; i++) {
const checkbox = document.createElement("input");
document.body.appendChild(checkbox);
checkbox.type = "checkbox";
checkbox.style.margin = 0;
checkbox.addEventListener("mouseover", e => {
e.target.checked = !e.target.checked;
});
checkbox.addEventListener("mouseout", e =>
setTimeout(() => {
e.target.checked = !e.target.checked;
}, 1000)
);
}See also event delegation which lets you add a single listener on many child elements.
Here is a starter... About the math addition. Since your question was tag with jQuery, It's a jQuery way.
Notice that the form will only send something like {vehicle:['on','','on','on']}... Which is way far from anyone would want to send to the server. But that is another question.
<html>
<head>
<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
</head>
<body>
<h2>Please choose a seat to book</h2>
<form action="/action_page.php" method="post">
<input type="checkbox" name="vehicle" id="A1" value="100">$100<br>
<input type="checkbox" name="vehicle" id="A2" value="65"> $65<br>
<input type="checkbox" name="vehicle" id="A3" value="55"> $55<br>
<input type="checkbox" name="vehicle" id="A4" value="50"> $50<br>
Selected Seat(s): <span id="seats"></span>
<br>
<br>
Total: $<span id="demo">0.00</span> USD <input type="submit" value="Reserve Now">
</form>
<script>
$(document).ready(function(){
var total=0;
var seats=[];
$("form input").on("click",function(){
var id=$(this).attr("id");
if($(this).is(":checked")){
total+=parseInt($(this).val());
seats.push(id);
}else{
total-=parseInt($(this).val());
seats.splice(seats.indexOf(id),1);
}
$("#demo").text(total.toFixed(2));
$("#seats").html(seats.sort().join(","));
});
});
</script>
</body>
</html>