Develop Reference

Javascript: Cannot move back in HTML Input

I have a form where a user can enter a URL but I wanted to have it automatically remove spaces.
To do this I have the following jQuery function:
$('#URL').on('change keyup', function() {
var sanitized = $(this).val().replace(' ', '');
$(this).val(sanitized);
});
But the problem with this code is that you cannot use the arrow keys to move in the input. i.e. if I type in http://oogle.com and I want to use arrow keys to fix my spelling mistake, it will automatically keep the cursor on the very last character. On top of this, I cannot use Ctrl+A to select all the text.
Is there a way to have jQuery/Javascript automatically remove spaces while still being able to move around the input or select it all?
Here is my jsFiddle showing my issue.

Use keypress instead of keyup, so only characters are caught. In this case, discard a space if it is pressed.
Also check for a paste event, and use a regular expression to replace all spaces. Change the value within a timeout in order to capture the pasted value:
$('#URL')
.on('keypress', function(e) {
if(e.which === 32) return false;
})
.on('paste', function() {
$self= $(this);
setTimeout(function() {
$self.val($self.val().replace(/\s/g, ''));
});
});
Fiddle

Fiddle
You can:
Record the cursor position
Execute your original code
Then restore the cursor position
Update:
Make sure to change your .replace to .replace(/\ /g, "")
Update 2 (cursor position):
This fixes the cursor position when inserting spaces.
For example copy and pasting the following will now work with any cursor position:
341 10365
34 1 1 03 65
First you need to get the string to the left of the cursor:
var leftString = $(this).val().substring(0, start);
Then you need to count the spaces in that string:
var leftSpaces = (leftString.match(/ /g) || []).length;
Then subtract leftSpaces from the start and end variables.
Javascript
$('#URL').on('change keyup', function() {
// Store cursor position
var start = this.selectionStart;
var end = this.selectionEnd;
// Check for newly inserted spaces
var leftString = $(this).val().substring(0, start);
var leftSpaces = (leftString.match(/ /g) || []).length;
newStart = start - leftSpaces;
newEnd = end - leftSpaces;
// Original Code
var sanitized = $(this).val().replace(/\ /g, "");
$(this).val(sanitized);
// Place cursor in correct position
this.setSelectionRange(newStart, newEnd);
});

Another option would be to add a delay after the keyup event
$('#URL').on('change keyup', function() {
delay(function(){
var sanitized = $('#URL').val().replace(' ', '');
$('#URL').val(sanitized);
}, 1000 );
});
http://jsfiddle.net/xv2e9bLe/

The usual way to adjust user input in a form is done when user finish their input or edit. It's pretty awkward to adjust user input on the fly. So, the onBlur event usually the best event to catch and sanitize a form input.
Based on the answer from adriancarriger, I use the 'blur' event which catch the user input after the user finish the input and do something else.
$('#URL').on('blur', function() {
var start = this.selectionStart,
end = this.selectionEnd;
var sanitized = $(this).val().replace(/\ /g, "");
$(this).val(sanitized);
this.setSelectionRange(start, end);
});
This should work well. If you have a real form submit, you can also catch the user input at onSubmit event of the form as well. Note that onSubmit happens at the form object, not the input object.

TAB keypress capturing not working

Hi I have written this JS script to capture a TAB keypress capture.
It captures and insert a \t in the current pointer location in the "pre" tag.
$m = jQuery.noConflict();
$m(document).keydown(function(event) {
var keyCode = event.which;
if(keyCode == 9) {
// alert(); if this is there the code works, but if i remove this the code doesn't work, i dont want to alert user every time he hits TAB
// get caret position/selection
var start = this.selectionStart;
var end = this.selectionEnd;
var $this = $m(this);
var value = $this.val();
// set textarea value to: text before caret + tab + text after caret
$this.val(value.substring(0, start)
+ "\t"
+ value.substring(end));
// put caret at right position again (add one for the tab)
this.selectionStart = this.selectionEnd = start + 1;
// prevent the focus lose
event.preventDefault();
}
});
<div class="masterContainer" onclick="setFocusDiv();">
<div class="lined"></div>
<pre id="inputId" class="nonlined" contenteditable="true" onkeyup="setLineNu();" onfocus="setLineNu();"></pre>
</div>
but my problem is that when i insert an alert in the script it works perfectrly and insert the \t but when i remove the alert then it does not work. Also there is a focus event there but the focus is lost after the TAB press.

You need to call preventDefault() on your event instead of on this

Getting caret position in IE works in one scenario, doesn't in another

I have an input element in HTML markup as below:
<input type="text" name="s" id="s" value="" />
I am changing the characters entered in this input element with Urdu ones (like a mini virtual keyboard), by using jQuery's keypress:
$("#s").keypress(function(e) {
var pos = getCaretPos('s');
// key-mapping logic here
});
I also have some buttons that help a user enter their desired Urdu character by clicking on a respective button. Thus:
// Process clicks on buttons with class=kb-letter
$(".kb-letter").click(function() {
var pos = getCaretPos('s');
// logic for entering Urdu characters in 's' here
});
This is the function for getting caret position. It returns the current caret position in s and the new character is then inserted at that position:
function getCaretPos(areaId) {
var txtArea = document.getElementById(areaId);
var pos = 0;
var br = (document.selection ? "ie" : ((txtArea.selectionStart || txtArea.selectionStart == '0') ? "ff" : false ) );
if (br == "ie") {
txtArea.focus();
var range = document.selection.createRange();
range.moveStart ('character', -txtArea.value.length);
pos = range.text.length;
}
else if (br == "ff") {
pos = txtArea.selectionStart;
}
return pos;
}
Now, the above getCaretPos() works fine in Firefox 8 and Chrome 17 for both direct keyboard input in s and input using clicking on buttons; but on Internet Explorer 8, it works only for direct keyboard input. If I try entering a character using mouse clicks, it gets entered at location 0 because getCaretPos() always returns 0 in that case.
I have no idea what is going wrong. Do I need to call getCaretPos() in a different manner in response to mouse clicks for IE?

Never mind. I was using an unordered list with its <li>s posing as keyboard buttons. For some reason, IE was having problems with them. I swapped the <li>s for <button>s and now getCaretPos() is working all fine.

Keypress in jQuery: Press TAB inside TEXTAREA (when editing an existing text)

I want to insert TAB characters inside a TEXTAREA, like this:
<textarea>{KEYPRESS-INSERTS-TAB-HERE}Hello World</textarea>
I can insert before/after the existing TEXTAREA text - and I can insert / replace all text in the TEXTAREA - but have not yet been able to insert inside the existing TEXTAREA text (by the cursor) in a simple way.
$('textarea:input').live('keypress', function(e) {
if (e.keyCode == 9) {
e.preventDefault();
// Press TAB to append a string (keeps the original TEXTAREA text).
$(this).append("TAB TAB TAB AFTER TEXTAREA TEXT");
// Press TAB to append a string (keeps the original TEXTAREA text).
$(this).focus().prepend("TAB TAB TAB BEFORE TEXTAREA TEXT");
// Press TAB to replace a all text inside TEXTAREA.
$(this).val("INSERT INTO TEXTAREA / REPLACE EXISTING TEXT");
}
});
There is a "tabs in textarea" plug-in for jQuery ("Tabby") - but it's 254 code lines - I was hoping for just a few lines of code.
A few links that I studied: (again, I would prefer fewer code lines).
http://www.dynamicdrive.com/forums/showthread.php?t=34452
http://www.webdeveloper.com/forum/showthread.php?t=32317
http://pallieter.org/Projects/insertTab/
Please advise. Thanks.

I was creating a AJAX powered simple IDE for myself so I can rapidly test out PHP snippets.
I remember stumbling upon the same problem, here's how I solved it:
$('#input').keypress(function (e) {
if (e.keyCode == 9) {
var myValue = "\t";
var startPos = this.selectionStart;
var endPos = this.selectionEnd;
var scrollTop = this.scrollTop;
this.value = this.value.substring(0, startPos) + myValue + this.value.substring(endPos,this.value.length);
this.focus();
this.selectionStart = startPos + myValue.length;
this.selectionEnd = startPos + myValue.length;
this.scrollTop = scrollTop;
e.preventDefault();
}
});
#input is the ID of the textarea.
The code is not completely mine, I found it on Google somewhere.
I've only tested it on FF 3.5 and IE7. It does not work on IE7 sadly.

Unfortunately, manipulating the text inside textarea elements is not as simple as one might hope. The reason that Tabby is larger than those simple snippets is that it works better. It has better cross-browser compatibility and handles things like tabbing selections.
When minified, it's only about 5k. I'd suggest using it. You'll either have to discover and troubleshoot those same edge cases yourself anyway, or might not even know about them if users don't report them.

Yeah, dealing with input field selections across the different browsers is an annoyance, especially as in IE there are a few methods that look like they should work but actually don't. (Notably, combining using setEndPoint then measuring length, which looks OK until the selection starts or ends in newlines.)
Here's a couple of utility functions I use to deal with input selections. It returns the value of the input split into bits that are before, inside and after the selection (with the selection counting as an empty string at the input focus position if it's not a selection). This makes it fairly simply to replace and insert content at the point you want, whilst taking care of the IE CRLF problem.
(There may be a jQuery that does something like this, but I have yet to meet one.)
// getPartitionedValue: for an input/textarea, return the value text, split into
// an array of [before-selection, selection, after-selection] strings.
//
function getPartitionedValue(input) {
var value= input.value;
var start= input.value.length;
var end= start;
if (input.selectionStart!==undefined) {
start= input.selectionStart;
end= input.selectionEnd;
} else if (document.selection!==undefined) {
value= value.split('\r').join('');
start=end= value.length;
var range= document.selection.createRange();
if (range.parentElement()===input) {
var start= -range.moveStart('character', -10000000);
var end= -range.moveEnd('character', -10000000);
range.moveToElementText(input);
var error= -range.moveStart('character', -10000000);
start-= error;
end-= error;
}
}
return [
value.substring(0, start),
value.substring(start, end),
value.substring(end)
];
}
// setPartitionedValue: set the value text and selected region in an input/
// textarea.
//
function setPartitionedValue(input, value) {
var oldtop= input.scrollTop!==undefined? input.scrollTop : null;
input.value= value.join('');
input.focus();
var start= value[0].length;
var end= value[0].length+value[1].length;
if (input.selectionStart!==undefined) {
input.selectionStart= start;
input.selectionEnd= end;
if (oldtop!==null)
input.scrollTop= oldtop;
}
else if (document.selection!==undefined) {
var range= input.createTextRange();
range.collapse(true);
range.moveEnd('character', end);
range.moveStart('character', start);
range.select();
}
}

btw, see also:
http://aspalliance.com/346_Tabbing_in_the_TextArea

How do I insert a character at the caret with javascript?

I want to insert some special characters at the caret inside textboxes using javascript on a button. How can this be done?
The script needs to find the active textbox and insert the character at the caret in that textbox. The script also needs to work in IE and Firefox.
EDIT: It is also ok to insert the character "last" in the previously active textbox.

I think Jason Cohen is incorrect. The caret position is preserved when focus is lost.
[Edit: Added code for FireFox that I didn't have originally.]
[Edit: Added code to determine the most recent active text box.]
First, you can use each text box's onBlur event to set a variable to "this" so you always know the most recent active text box.
Then, there's an IE way to get the cursor position that also works in Opera, and an easier way in Firefox.
In IE the basic concept is to use the document.selection object and put some text into the selection. Then, using indexOf, you can get the position of the text you added.
In FireFox, there's a method called selectionStart that will give you the cursor position.
Once you have the cursor position, you overwrite the whole text.value with
text before the cursor position + the text you want to insert + the text after the cursor position
Here is an example with separate links for IE and FireFox. You can use you favorite browser detection method to figure out which code to run.
<html><head></head><body>
<script language="JavaScript">
<!--
var lasttext;
function doinsert_ie() {
var oldtext = lasttext.value;
var marker = "##MARKER##";
lasttext.focus();
var sel = document.selection.createRange();
sel.text = marker;
var tmptext = lasttext.value;
var curpos = tmptext.indexOf(marker);
pretext = oldtext.substring(0,curpos);
posttest = oldtext.substring(curpos,oldtext.length);
lasttext.value = pretext + "|" + posttest;
}
function doinsert_ff() {
var oldtext = lasttext.value;
var curpos = lasttext.selectionStart;
pretext = oldtext.substring(0,curpos);
posttest = oldtext.substring(curpos,oldtext.length);
lasttext.value = pretext + "|" + posttest;
}
-->
</script>
<form name="testform">
<input type="text" name="testtext1" onBlur="lasttext=this;">
<input type="text" name="testtext2" onBlur="lasttext=this;">
<input type="text" name="testtext3" onBlur="lasttext=this;">
</form>
Insert IE
<br>
Insert FF
</body></html>
This will also work with textareas. I don't know how to reposition the cursor so it stays at the insertion point.

In light of your update:
var inputs = document.getElementsByTagName('input');
var lastTextBox = null;
for(var i = 0; i < inputs.length; i++)
{
if(inputs[i].getAttribute('type') == 'text')
{
inputs[i].onfocus = function() {
lastTextBox = this;
}
}
}
var button = document.getElementById("YOURBUTTONID");
button.onclick = function() {
lastTextBox.value += 'PUTYOURTEXTHERE';
}

Note that if the user pushes a button, focus on the textbox will be lost and there will be no caret position!

loop over all you input fields...
finding the one that has focus..
then once you have your text area...
you should be able to do something like...
myTextArea.value = 'text to insert in the text area goes here';

I'm not sure if you can capture the caret position, but if you can, you can avoid Jason Cohen's concern by capturing the location (in relation to the string) using the text box's onblur event.

A butchered version of #bmb code in previous answer works well to reposition the cursor at end of inserted characters too:
var lasttext;
function doinsert_ie() {
var ttInsert = "bla";
lasttext.focus();
var sel = document.selection.createRange();
sel.text = ttInsert;
sel.select();
}
function doinsert_ff() {
var oldtext = lasttext.value;
var curposS = lasttext.selectionStart;
var curposF = lasttext.selectionEnd;
pretext = oldtext.substring(0,curposS);
posttest = oldtext.substring(curposF,oldtext.length);
var ttInsert='bla';
lasttext.value = pretext + ttInsert + posttest;
lasttext.selectionStart=curposS+ttInsert.length;
lasttext.selectionEnd=curposS+ttInsert.length;
}