I googled and got the following codes on the Net.However, when I press a keyboard key,it is not displaying me an alert box. I want to get which character I have pressed in the alert box. How do I fix this?
<script type="text/javascript">
var charfield=document.getElementById("char")
charfield.onkeydown=function(e){
var e=window.event || e;
alert(e.keyCode);
}
</script>
</head>
<body id="char">
</body>
</html>
If you want to get the character typed, you must use the keypress event rather than the keydown event. Something like the following:
var charfield = document.getElementById("char");
charfield.onkeypress = function(e) {
e = e || window.event;
var charCode = (typeof e.which == "number") ? e.which : e.keyCode;
if (charCode > 0) {
alert("Typed character: " + String.fromCharCode(charCode));
}
};
try this jquery code
$("body").keypress(function(e){
alert(e.which);
});
I can't off the top of my head think of a good situation in which to use the "on some event" method of a DOM element to deal with events on that element.
The best practice is to use addEventListener (or attachEvent in older versions of Internet Explorer) like so:
charfield.addEventListener('keydown', function (e) { alert(e.keyCode); }, false);
If you want to account for attachEvent as well:
(function (useListen) {
if (useListen) {
charfield.addEventListener('keydown', alertKeyCode, false);
} else {
charfield.attachEvent('onkeydown', alertKeyCode);
}
})(charfield.addEventListener);
function alertKeyCode(e) {
alert(e.keyCode);
}
You'll get the appropriate key code:
charfield.onkeydown=function(evt){
var keyCode = (evt.which?evt.which:(evt.keyCode?evt.keyCode:0))
alert(keyCode);
}
Related
Possible Duplicate:
Which keycode for escape key with jQuery
How to detect escape key press in IE, Firefox and Chrome?
Below code works in IE and alerts 27, but in Firefox it alerts 0
$('body').keypress(function(e){
alert(e.which);
if(e.which == 27){
// Close my modal window
}
});
Note: keyCode is becoming deprecated, use key instead.
function keyPress (e) {
if(e.key === "Escape") {
// write your logic here.
}
}
Code Snippet:
var msg = document.getElementById('state-msg');
document.body.addEventListener('keypress', function(e) {
if (e.key == "Escape") {
msg.textContent += 'Escape pressed:'
}
});
Press ESC key <span id="state-msg"></span>
keyCode is becoming deprecated
It seems keydown and keyup work, even though keypress may not
$(document).keyup(function(e) {
if (e.key === "Escape") { // escape key maps to keycode `27`
// <DO YOUR WORK HERE>
}
});
Which keycode for escape key with jQuery
The keydown event will work fine for Escape and has the benefit of allowing you to use keyCode in all browsers. Also, you need to attach the listener to document rather than the body.
Update May 2016
keyCode is now in the process of being deprecated and most modern browsers offer the key property now, although you'll still need a fallback for decent browser support for now (at time of writing the current releases of Chrome and Safari don't support it).
Update September 2018
evt.key is now supported by all modern browsers.
document.onkeydown = function(evt) {
evt = evt || window.event;
var isEscape = false;
if ("key" in evt) {
isEscape = (evt.key === "Escape" || evt.key === "Esc");
} else {
isEscape = (evt.keyCode === 27);
}
if (isEscape) {
alert("Escape");
}
};
Click me then press the Escape key
Using JavaScript you can do check working jsfiddle
document.onkeydown = function(evt) {
evt = evt || window.event;
if (evt.keyCode == 27) {
alert('Esc key pressed.');
}
};
Using jQuery you can do check working jsfiddle
jQuery(document).on('keyup',function(evt) {
if (evt.keyCode == 27) {
alert('Esc key pressed.');
}
});
check for keyCode && which & keyup || keydown
$(document).keydown(function(e){
var code = e.keyCode || e.which;
alert(code);
});
Pure JS
you can attach a listener to keyUp event for the document.
Also, if you want to make sure, any other key is not pressed along with Esc key, you can use values of ctrlKey, altKey, and shifkey.
document.addEventListener('keydown', (event) => {
if (event.key === 'Escape') {
//if esc key was not pressed in combination with ctrl or alt or shift
const isNotCombinedKey = !(event.ctrlKey || event.altKey || event.shiftKey);
if (isNotCombinedKey) {
console.log('Escape key was pressed with out any group keys')
}
}
});
pure JS (no JQuery)
document.addEventListener('keydown', function(e) {
if(e.keyCode == 27){
//add your code here
}
});
Below is the code that not only disables the ESC key but also checks the condition where it is pressed and depending on the situation, it will do the action or not.
In this example,
e.preventDefault();
will disable the ESC key-press action.
You may do anything like to hide a div with this:
document.getElementById('myDivId').style.display = 'none';
Where the ESC key pressed is also taken into consideration:
(e.target.nodeName=='BODY')
You may remove this if condition part if you like to apply to this to all. Or you may target INPUT here to only apply this action when the cursor is in input box.
window.addEventListener('keydown', function(e){
if((e.key=='Escape'||e.key=='Esc'||e.keyCode==27) && (e.target.nodeName=='BODY')){
e.preventDefault();
return false;
}
}, true);
Best way is to make function for this
FUNCTION:
$.fn.escape = function (callback) {
return this.each(function () {
$(document).on("keydown", this, function (e) {
var keycode = ((typeof e.keyCode !='undefined' && e.keyCode) ? e.keyCode : e.which);
if (keycode === 27) {
callback.call(this, e);
};
});
});
};
EXAMPLE:
$("#my-div").escape(function () {
alert('Escape!');
})
On Firefox 78 use this ("keypress" doesn't work for Escape key):
function keyPress (e)(){
if (e.key == "Escape"){
//do something here
}
document.addEventListener("keyup", keyPress);
i think the simplest way is vanilla javascript:
document.onkeyup = function(event) {
if (event.keyCode === 27){
//do something here
}
}
Updated: Changed key => keyCode
I am trying to figure out when a key press is an empty space, so I did the following:
if (e.which == ' '){
}
however this does not work. Any idea why?
event.which returns the code of the character pressed. space key code is 32, so use it instead:
if (e.which === 32) {
//
}
Another way is to convert character to char code with .charCodeAt():
if (e.which === " ".charCodeAt(0)) {
//
}
CHECK: http://www.cambiaresearch.com/articles/15/javascript-char-codes-key-codes
Write a test code and alert what the keyCode is.
document.onkeypress = function(e) {
e = e || window.event;
console.log(e.keyCode || e.which);
};
Learn to debug and you would not be asking these simple questions.
jQuery would have been
$(document).keypress(
function (e) {
console.log(e.which);
}
);
Probably this is what you're looking for: (Assuming you use the keydown event.)
if(e.keyCode == '32') {
// Your code
}
jsFiddle:
http://jsfiddle.net/DeHFL/
<input type="button" id="save_post" class="button" value="Post" style="cursor:pointer;"/>
How can I bind the enter key on the persons keyboard to this specific button on the page? It's not in a form, and nor do I want it to be.
Thanks!
This will click the button regardless of where the "Enter" happens on the page:
$(document).keypress(function(e){
if (e.which == 13){
$("#save_post").click();
}
});
If you want to use pure javascript :
document.onkeydown = function (e) {
e = e || window.event;
switch (e.which || e.keyCode) {
case 13 : //Your Code Here (13 is ascii code for 'ENTER')
break;
}
}
using jQuery :
$('body').on('keypress', 'input', function(args) {
if (args.keyCode == 13) {
$("#save_post").click();
return false;
}
});
Or to bind specific inputs to different buttons you can use selectors
$('body').on('keypress', '#MyInputId', function(args) {
if (args.keyCode == 13) {
$('#MyButtonId').click();
return false;
}
});
Vanilla JS version with listener:
window.addEventListener('keyup', function(event) {
if (event.keyCode === 13) {
alert('enter was pressed!');
}
});
Also don't forget to remove event listener, if this code is shared between the pages.
Maybe not quite what you're looking for but there is a HTML property that lets you assign a specific button called an access key to focus or trigger an element. It's like this:
<a href='https://www.google.com' accesskey='h'>
This can be done with most elements.
Here's the catch: it doesn't always work. for IE and chrome, you need to be holding alt as well. On firefox, you need to be holding alt and shift (and control if on mac). For safari, you need to be holding control and alt. On opera 15+ you need alt, before 12.1 you need shift and esc.
Source: W3Schools
I'm trying to disable the backspace button on an order page in all cases except when a textarea or text input is an active element to prevent users from accidentally backing out of an order. I have it working fine in most browsers, but in IE (testing in IE9, both regular and compatibility mode) it still allows the user to hit the backspace and go to the previous page.
Here's the code:
$(document).keypress(function(e){
var activeNodeName=document.activeElement.nodeName;
var activeElType=document.activeElement.type;
if (e.keyCode==8 && activeNodeName != 'INPUT' && activeNodeName != 'TEXTAREA'){
return false;
} else {
if (e.keyCode==8 && activeNodeName=='INPUT' && activeElType != 'TEXT' && activeElType != 'text'){
return false;
}
}
});
Any advice on what I'm doing wrong here?
Thanks!
I think you're overcomplicating that. Rather than checking for an active element, find the event target instead. This should give you the information you need. It's also better to use keydown rather than keypress when there is no visible character. Finally, it's better to use e.preventDefault() for better granularity.
$(document).keydown(function(e) {
var nodeName = e.target.nodeName.toLowerCase();
if (e.which === 8) {
if ((nodeName === 'input' && e.target.type === 'text') ||
nodeName === 'textarea') {
// do nothing
} else {
e.preventDefault();
}
}
});
NB I could have done this the other way round, rather than an empty if block and all the code going in the else block, but I think this is more readable.
Instead of keypress, try the keydown function, it will fire before the actual browser based hook. Also, putting in a preventDefault() function will assist in this. IE :
$(document).keydown(function(e){
e.preventDefault();
alert(e.keyCode);
});
Hope this helps.
The most Simple thing you can do is add the following one line in the very first script of you page at very first line
window.history.forward(1);
Most examples seem to be for the JQuery framework - Here an example for ExtJS
(I've been getting a lot of downvotes for this recently as the question now has JQuery tag on it, which it didn't previously. I can remove the answer if you like as isn't for JQuery but it's proven to help others not using that framework).
To use this add this code block to your code base, I recommend adding it inside the applications init function().
/**
* This disables the backspace key in all browsers by listening for it on the keydown press and completely
* preventing any actions if it is not which the event fired from is one of the extjs nodes that it should affect
*/
Ext.EventManager.on(window, 'keydown', function(e, t) {
var nodeName = e.target.nodeName.toLowerCase();
if (e.getKey() == e.BACKSPACE) {
if ((nodeName === 'input' && e.target.type === 'text') ||
nodeName === 'textarea') {
// do nothing
} else {
e.preventDefault();
}
}
});
Use e.which instead of e.keyCode; jQuery normalizes this value across browsers.
http://api.jquery.com/keydown/
To determine which key was pressed,
examine the event object that is
passed to the handler function. While
browsers use differing properties to
store this information, jQuery
normalizes the .which property so you
can reliably use it to retrieve the
key code.
Then, use e.preventDefault(); to prevent the default behaviour of moving to the previous page.
<html>
<head>
<script type="text/javascript">
function stopKey(evt) {
var evt = (evt) ? evt : ((event) ? event : null);
var node = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
if ((evt.keyCode == 8) && (node.type!="text")) {return false;}
}
document.onkeypress = stopKey;
</script>
</head>
<body onkeydown="return stopKey()">
<form>
<input type="TEXTAREA" name="var1" >
<input type="TEXT" name="var2" >
</form>
</body>
</html
I had to add the onDownKey attribute to the body in order to get editing keys to go to the functions.
$(document).keydown(function(e) {
var elid = $(document.activeElement).is('input');
if (e.keyCode === 8 && !elid) {
return false;
}
});
Hope this might help you
Seems like the "backspace" will also act as "navigation back" if you have selected radio buttons, check-boxes and body of document as well. Really annoying for forms - especially when using post. All the form could be lost with one slip of the "backspace" key -_- ...
Honestly... who's idea was it to allow the "backspace as a navigational "back" button!!! really bad idea in my opinion.
I disable the "backspace" default on anything that is not a text area or text field - like this:
$(document).keydown(function(e){
console.log(e.keyCode+"\n");
var typeName = e.target.type;//typeName should end up being things like 'text', 'textarea', 'radio', 'undefined' etc.
console.log(typeName+"\n");
// Prevent Backspace as navigation backbutton
if(e.keyCode == 8 && typeName != "text" && typeName != "textarea"){
console.log("Prevent Backbutton as Navigation Back"+typeName+"\n");
e.preventDefault();
}
//
})
Not sure where else one would want the normal behavior of a back-button other than in these two areas.
document.onkeydown = KeyPress;
function KeyPress(e) {
if (!e.metaKey){
e.preventDefault();
}
}
I have multiple fields, typically enter will be pressed on one of the two main ones. I want to know which field enter has been pressed on, how do i do this? (i dont know much JS)
its simple to add an "onkeypress" event to each of the fields, and then in the event handler to examine the keycode that is attached to the event. For example, consider the following code:
form.elements['fieldone'].onkeypress = function(evt) {
if (window.event) evt = window.event; // support IE
if (evt.keyCode == 13) alert("Enter was pressed!");
return true;
}
Please note that under most browsers, pressing ENTER in a form field would post that form. If you don't want that to happen, you can simply return false from the onkeypress handler and that would tell the browser to ignore that key.
Check for enter and set some hidden field (example uses JQuery):
$('#input_text').keyup(function(e) {
//alert(e.keyCode);
if(e.keyCode == 13) {
alert('Enter key was pressed.');
}
});
Include this in your page, it should fire automatically when you hit any key and tell you which html element had focus when it happened.
<script>
document.onkeypress = KeyPressed;
function KeyPressed(e)
{
if (!e) e = window.event;
f ((e.charCode) && (e.keyCode == 13))
alert('Yay! Enter was pressed while field ' + document.activeElement.id + ' had focus!');
}
</script>
You can check from which element the event bubbled from using something like the following
var text1 = document.getElementById('text1');
var text2 = document.getElementById('text2');
text1.onkeypress = keyPresser;
text2.onkeypress = keyPresser;
function keyPresser(e) {
// to support IE event model
var e = e || window.event;
var originalElement = e.srcElement || e.originalTarget;
if (e.keyCode === 13) {
alert(originalElement.id);
}
}
Here's a Working Demo
I would recommend taking a look at the differences in Browser event models and also at unobtrusive JavaScript .
QuirksMode - Introduction to Events
The IE Event Model
Pro JavaScript Techniques - Unobtrusive Event Binding
Use event delegation to avoid attaching event handlers to a large number of elements:
window.onload = function () {
document.onkeyup = function (e) {
e = e || window.event;
var target = e.target || e.srcElement,
keyCode = e.keyCode || e.which;
if (target.tagName.toLowerCase() == 'input' && keyCode == 13) {
alert('Enter pressed on ' + target.id);
}
};
};