I want to create a small count button but don't know how to make it in JavaScript...
Here's the code :
HTML
<div id="input_div">
<input type="text" size="25" value="0" id="count">
<input type="button" value="-" id="moins">
<input type="button" value="+" id="plus">
</div>
It must increase AND decrease the number in the input[type=text] when click on the -/+ button.
Can someone help me ?
You'd need two things.
Variables - which are the way to store information in JavaScript
Event handlers, which are the way to react to events in JavaScript
First, let's create a script tag, and put a JavaScript count variable in it, we'll put it in the bottom of our body tag:
<script>
var count = 0;
</script>
Now, we want to create a handler, that is something that executes whenever the plus and minus signs are clicked
<script>
var count = 0;
function plus(){
count++;
}
function minus(){
count--;
}
</script>
We've created two functions to call when the buttons are clicked, but we do not update the value in the HTML, or call them yet, let's update the value in the HTML.
We'll do so by document.getElementByID for the element to update and then change its value. Our script tag should look something liks this:
<script>
var count = 0;
var countEl = document.getElementById("count");
function plus(){
count++;
countEl.value = count;
}
function minus(){
count--;
countEl.value = count;
}
</script>
One last thing, we need to tell the elements in the DOM to execute those handlers.
<div id="input_div">
<input type="text" size="25" value="0" id="count">
<input type="button" value="-" id="moins" onclick="minus()">
<input type="button" value="+" id="plus" onclick="plus()">
</div>
We've added them as event handlers to the DOM reacting to a click on the buttons, completing the task.
Now, here are some things we can improve:
We can use addEventListener to avoid polluting our DOM, and create unobtrusive JavaScript.
We can use a more advanced tool like KnockoutJS to handle binding the value we have to the DOM element instead of updating it ourselves.
We can read Eloquent JavaScript and learn more about how the language works!
Good luck, happy JavaScripting, and happy learning :)
DEMO FIDDLE FOR JAVASCRIPT
code html -
<div id="input_div">
<input type="text" size="25" value="0" id="count" />
<input type="button" value="-" id="minus" onClick = "doMinus();" />
<input type="button" value="+" id="plus" onClick = "doPlus();" />
</div>
code javaScript -
function doMinus(){
document.getElementById("count").value = --document.getElementById("count").value;
}
function doPlus(){
document.getElementById("count").value = ++document.getElementById("count").value;
}
jQuery Version
DEMO FIDDLE FOR JQUERY
code html -
<div id="input_div">
<input type="text" size="25" value="0" id="count" />
<input type="button" value="-" id="minus" />
<input type="button" value="+" id="plus" />
</div>
code jQuery -
$('#minus').click(function(){
$("#count").val(parseInt($("#count").val())-1);
});
$('#plus').click(function(){
$("#count").val(parseInt($("#count").val())+1);
});
U can write some script as shown
<script>
function increase(){
var a = 1;
var textBox = document.getElementById("count");
textBox.value = a;
a++;
}
</script>
<body>
<button type="button" onclick="increase()">+</button>
<input type="text" id="text">
</body>
similarly u can do it for - decrease button
in this case, I use input type range that display a slider :
<input type="range" id="myInputRange" value="15" min="0" max="50" step="1" onchange="document.getElementById('output').textContent=value" ><span id="output">15</span>
(instead of input type number that is not supported by IE)
This seems pretty simple.
(function() {
var count = 0;
var minusButton = document.getElementById("moins");
var plusButton = document.getElementById("plus");
var countBox = document.getElementById("count");
minusButton.onclick = function(e) {
countBox.value = --count;
};
plusButton.onclick = function(e) {
countBox.value = ++count;
};
})();
Related
Hello I'm trying to get my contact form to display a thank you message after the message has been sent.
I looked around but the stuff I find looks more complex than what I think i need.
I think it's something i'm missing about the event listener and how this form works.
Here's my code:
.thanks {
display: none;
}
<div class="form-wrap">
<form class="contact-form" action="https://getsimpleform.com/messages?form_api_token=aa0a1c58e87ea8816ba9ff7d7a71d0ef" method="post">
<!-- all your input fields here.... -->
<div class="name-email">
<input class="contact-field contactform-name" type='text' name='name' placeholder="Name" required/>
<input class="contact-field contact-form-email" type="email:" name="email" placeholder="e-mail" value="" required>
</div>
<textarea class="contact-field" name="message" rows="20" cols="80" placeholder="Your Message" required></textarea>
<input class="contact-field submit" type='submit' value='Send' />
</form>
</div>
<div class="thanks">
<h1>Thanks for the message!</h1>
</div>
<script>
function displayThanks() {
document.querySelector(".thanks").style.display = "block";
document.querySelector(".contact-form").style.display = "none";
}
document.querySelector(".submit").addEventListener("submit", displayThanks)
</script>
I could make it work on click, but that would mean that even if they don't send a message and just click submit they will get thank you (FOR WHAT!?)
Thanks!
M
You are mixing client side logic with server side logic. It's hard to answer your question because we don't know, what the action "action="https://getsimpleform.com/messages?form_api_token=aa0a1c58e87ea8816ba9ff7d7a71d0ef" in your form tag is doing.
It might be usefull to validate the form, before you consider to submit it. You can do this by using the click event of the submit button in combination with preventDefault like this (Just an Example, you could even use RegEx for emails and stuff):
document.querySelector(".submit").addEventListener('click', function(e) {
var userInputName = document.getElementsByName("name")[0].value,
userInputEmail = document.getElementsByName("email")[0].value,
userInputMessage = document.getElementsByName("message")[0].value;
if (userInputName.length > 0 && userInputEmail.length > 0 && userInputMessage.length > 0)
{
document.querySelector(".thanks").style.display = "block";
document.querySelector(".contact-form").style.display = "none";
}
else
{
e.preventDefault();
}
}, false);
I would recommend to use IDs instead of names though, because IDs are unique and don't require a node list or ambiguous jQuery. Than you can use something like this: userInputName = document.getElementById("name").value;
And don't forget to use the right CSS for your logic. Like:
.thanks {display: none;}
Suppose I have an input person name and another input business name:
<input name="nameofperson" id="nameofperson" class="form-control">
<input name="nameofbusiness" id="nameofbusiness" class="form-control" value="1234567">
If I started writing something on the nameofperson input. I want to clear the value of nameofbusiness, how to do that using CSS?
What you want to do is not possible through the Css,but you can do that using javascript or jquery.
With Javascript :
var nameofperson = document.getElementById('nameofperson');
var nameofbusiness = document.getElementById('nameofbusiness');
nameofperson.oninput = function() {
nameofbusiness.value = '';
}
<input type="text" name="nameofperson" id="nameofperson" class="form-control">
<input type="text" name="nameofbusiness" id="nameofbusiness" class="form-control" value="1234567">
With Jquery :
$(document).ready(function(){
$('#nameofperson').keyup(function(){
$('#nameofbusiness').val('');
})
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" name="nameofperson" id="nameofperson" class="form-control">
<input type="text" name="nameofbusiness" id="nameofbusiness" class="form-control" value="1234567">
You can't clear an input field's value using CSS. However, you can use JavaScript/JQuery for that.
Please find the working example.
$("#person").on("keyup", function(){
$("#business").val("");
});
input {
width: 350px;
height: 30px;
text-indent: 5;
margin-bottom: 10px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="person" placeholder="Enter name of person">
<input type="text" id="business" placeholder="Enter your Business">
You add same class name for both input. For exampale I add 'nameofSomething' class.
and the jquery
$(".nameofSomething").keypress(function () {
var id = $(this).attr('id')
var text = $("#" + id).val();
$(".nameofSomething").val('');
$("#" + id).val(text);
});
You can change keypress to change, blur...or whatever you want.
This is basically done by javascript and not by css.
CSS as the name says is for styling purpose.
you can do this by javascript easily using onfocus method:
<input type="text" onfocus="document.getElementById('nameofbusiness').value = ''">
I want to find the default tab index of the form.
I have not given but still all the control has the tab index. I want to find that default tab index through the j query. How can i find that?
Jquery and tab-index
The way tabindexing works is that it goes trough your html markup and looks for tabable elements.
So say you have this code:
<form>
<label>Name:</label>
<input type="text" />
<br>
<input type="submit" />
</form>
The text input will be tabbed first, and then the submit input.
Yes i know this how do it get the tabbing?
$(function() {
$firstinput = $("form").find("input")
console.log($firstinput.first()); //prints the first element thats an input.
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
<label>Name:</label>
<input type="text" />
<br>
<input type="submit" />
</form>
The code above will only work if you only have input elemtns and add not trickery to the markup like hiding your elements etc.
In the code below im using the jquery UI :focusable selector.
With this you should get the first tabbable element in your form
//:focus selector from jquery UI
$.extend($.expr[':'], {
focusable: function(element) {
var nodeName = element.nodeName.toLowerCase(),
tabIndex = $.attr(element, 'tabindex');
return (/input|select|textarea|button|object/.test(nodeName) ? !element.disabled : 'a' == nodeName || 'area' == nodeName ? element.href || !isNaN(tabIndex) : !isNaN(tabIndex))
// the element and all of its ancestors must be visible
// the browser may report that the area is hidden
&& !$(element)['area' == nodeName ? 'parents' : 'closest'](':hidden').length;
}
});
//actual code
$(function() {
$form = $("form");
$first = $form.find(":focusable").first();
console.log($first);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
<label tab-index="0">Name:</label>
<input type="text" />
<br>
<input type="submit" />
</form>
You can search for 'tabindex' attribute with jquery.
var tabindexVal = $('selector').attr('tabindex');
I'm currently doing the following to compensate for boolean's not mapping well to radio buttons. I am stuck binding 1 and 0 to the value (instead of true and false) because of how the fields are read out of the observables. The value of Pref1/Pref2 come as true/false boolean values from the server. The key here is I want to not only data-bind the checked value of the radio button to match the true/false in the object, but I also want the boolean value of true/false to be written back into the GraduationClass object. My compensation code is not only ugly, but not scalable.
<input type="radio" value="1" name="radioGroup" data-bind="checked: Pref1" />Yes
<input type="radio" value="0" name="radioGroup" data-bind="checked: Pref2" />No
Save
function SiteSettingsViewModel() {
var self = this;
this.saveGraduationClass = function(graduationClass) {
// hack until i get a custom radio button binding
if (graduationClass.Pref1() == 1) {
graduationClass.Pref1(true);
} else {
graduationClass.Pref1(false);
}
if (graduationClass.Pref2() == 1) {
graduationClass.Pref2(true);
} else {
graduationClass.Pref2(false);
}
// ...ajax call to save graduationClass to the server
}
function GraduationClass(data) {
var self = this;
ko.mapping.fromJS(data, {}, this);
}
Here is example from knockoutJs website, that demonstrate how to use radio buttons with
"checked" attribute:
<p>Send me spam: <input type="checkbox" data-bind="checked: wantsSpam" /></p>
<div data-bind="visible: wantsSpam">
Preferred flavor of spam:
<div><input type="radio" name="flavorGroup" value="cherry" data-bind="checked: spamFlavor" /> Cherry</div>
<div><input type="radio" name="flavorGroup" value="almond" data-bind="checked: spamFlavor" /> Almond</div>
<div><input type="radio" name="flavorGroup" value="msg" data-bind="checked: spamFlavor" /> Monosodium Glutamate</div>
</div>
<script type="text/javascript">
var viewModel = {
wantsSpam: ko.observable(true),
spamFlavor: ko.observable("almond") // Initially selects only the Almond radio button
};
// ... then later ...
viewModel.spamFlavor("msg"); // Now only Monosodium Glutamate is checked
</script>
But I dont understand why you use two objects - "Pref1" and "Pref2" fro one radiobutton group "radioGroup"? In this case you just could use one object as in an example used "spamFlavor".
So, please, describe more ditaily what you want to bind: one radiobuttons group by one selected value, or something else.
Also you could use computed observables to calculate different values, please see example.
I am starter with Play Framework. I got a problem when i passed parameters.
I want to pass a collection from view to controller. And i do not know how to do this. I always get "null" when i get a collection from view.
My code below:
Code in controller:
public static void create(List<Book> books) throws Exception {
for(Book book : books){
System.out.println(book.get(0).author) // i got null :(
}
}
Code in HTML
Book 1:
<input type="text" name="books.author" />
<input type="text" name="books.title" />
Book 2:
<input type="text" name="books.author" />
<input type="text" name="books.title" />
When i submit, i want to add 2 records into database include Book1 and Book2. Please support me
Thanks
You can make this work by simplying add the array indicator to your HTML code
Book 1:
<input type="text" name="books[0].author" />
<input type="text" name="books[0].title" />
Book 2:
<input type="text" name="books[1].author" />
<input type="text" name="books[1].title" />
I have tested this solution, and it works fine.
Also note that your println will not compile, as you are calling get(0) on the Book object, and not the List object. If you just println book.author, it outputs the author as required.
In case anyone needs an example of the Javascript for dyanmically adding and removing books (JQUERY needed):
<script type="text/javascript">
$(document).ready(function() {
var bookCount=0;
$('#btnAddBook').click(function() {
bookCount++;
//newElem = go up a to the parent div then grab the previous container
var newElem = $(this).parent().prev().clone().attr('id', 'book[' + bookCount + ']');
//for each input inside the div, change the index to the latest bookCount
$(newElem).find("input").each(function(){
var name = $(this).attr('name');
var leftBracket = name.indexOf("[");
var rightBracket = name.indexOf("]");
var beforeBracketString = name.substring(0,leftBracket+1);//+1 to include the bracket
var afterBracketString = name.substring(rightBracket);
$(this).attr('name', beforeBracketString + bookCount + afterBracketString);
});
//insert it at the end of the books
$(this).parent().prev().after(newElem);
$(newElem).find("input").each(function(){
$(this).attr('id', $(this).attr('id') + bookCount);
});
//enable the remove button
$('#btnRemovebook').removeAttr('disabled');
//If we are at 16 divs, disable the add button
if (bookCount == 15)
$(this).attr('disabled','disabled');
});
$('#btnRemoveBook').click(function() {
bookCount--;
//remove the last book div
$(this).parent().prev().remove();
//in case add was disabled, enable it
$('#btnAddbook').removeAttr('disabled');
//never let them remove the last book div
if (bookCount == 0)
$(this).attr('disabled','disabled');
});
});
</script>
<!-- HTML Snippet -->
<div id="book[0]">
<label> Book: </label>
<input type="text" name="books[0].author" value="Author" />
<input type="text" name="books[0].title" value="Title" />
</div>
<div>
<input type="button" id="btnAddbook" value="Add another book" />
<input type="button" id="btnRemovebook" value="Remove last book" disabled="disabled" />
</div>
<!-- REST of the HTML -->