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[Zapages]

Hi guys,

I was wondering how do I enable the Backspace key, and the arrow keys on the keyboard so the user can scroll and fix their mistakes.

Currently I am using this to only allow users to enter a specific alphabet characters inside the textarea:

<script type="text/javascript">
var allow_backspace = true;
var arrValidChars=new Array("A", "C", "G", "N", "T", "a", "c", "g", "n", "t");
var arrSpecialChars = new Array(0, 2, 6, 13, 19, 26, 28, 32, 39, 45);
function VerifyCharacters(event, objInput) {
	var strText = objInput.value;
	var keyCode = event.keyCode||event.charCode;
	if (InArray(arrSpecialChars, keyCode) >= 0)
		return true;
	var strChar = String.fromCharCode(keyCode);
	return (InArray(arrValidChars, strChar)>=0);
}

function InArray(arr, key) {
	for (var i=0; i<arr.length; i++) {
		if (arr[i] == key)
			return i;
	}
	return -1;
}
</script>

and

this is my recall for the script in the textarea:

<textarea name="Sequence" cols="60" rows = "10"  onkeypress= "return VerifyCharacters(event, this)"> </textarea>

 

[Wads]

I assume you are talking about like having multiple text fields (like a phone number) and say they make a mistake in the 1st box and it moves to the 2nd box they can hit bs and get back to the 1st box?

 

[Zapages]

I assume you are talking about like having multiple text fields (like a phone number) and say they make a mistake in the 1st box and it moves to the 2nd box they can hit bs and get back to the 1st box?

Hmm... I was thinking just in one textbox...So they can just edit the allowed characters out. Nothing too crazy yet.

 

[Ghost]

Backspace and the arrow keys have their own keycodes, see http://www.webonweboff.com/tips/js/event_key_codes.aspx

It looks like you just need to add them to your array?

Unless i'm misunderstanding something.

 

[Prine]

Id maybe set this up so all valid characters entered are stored in a variable then pushed into the text area element, any invalid characters would flag a message. Allows you to screen the text input upon keyup event, and you dont have to explicitly target each keycode (like backspace, arrowkeys, shift etc ).

Hope that made sense. And use Jquery for the love of god!

 

[Crow]

Hi guys,

I was wondering how do I enable the Backspace key, and the arrow keys on the keyboard so the user can scroll and fix their mistakes.

Currently I am using this to only allow users to enter a specific alphabet characters inside the textarea:

<script type="text/javascript">
var allow_backspace = true;
var arrValidChars=new Array("A", "C", "G", "N", "T", "a", "c", "g", "n", "t");
var arrSpecialChars = new Array(0, 2, 6, 13, 19, 26, 28, 32, 39, 45);
function VerifyCharacters(event, objInput) {
	var strText = objInput.value;
	var keyCode = event.keyCode||event.charCode;
	if (InArray(arrSpecialChars, keyCode) >= 0)
		return true;
	var strChar = String.fromCharCode(keyCode);
	return (InArray(arrValidChars, strChar)>=0);
}

function InArray(arr, key) {
	for (var i=0; i<arr.length; i++) {
		if (arr[i] == key)
			return i;
	}
	return -1;
}
</script>

and

this is my recall for the script in the textarea:

<textarea name="Sequence" cols="60" rows = "10"  onkeypress= "return VerifyCharacters(event, this)"> </textarea>

Hmm, that seems to be a little more complicated than it needs to be.

EDIT: forgot about your backspace issue, revised the code to allow it.

Try this:

javascript

function VerifyCharacters2(event){

	var code = event.keyCode?event.keyCode:event.charCode;
	
	if(code == 8 || code == 37 || code == 39) return true; //allow backspace, arrow keys
	
	var character = String.fromCharCode(code);
	return /[acgntACGNT]/.test(character);
}

html

<input type="text" onkeypress="return VerifyCharacters2(event)" />

 

[Zapages]

^Thank you. I have one small question, what does the code == 8, etc suppose to indicate? I am just wondering?

 

[PetriP-TNT]

^Thank you. I have one small question, what does the code == 8, etc suppose to indicate? I am just wondering?

The event key codes

http://www.webonweboff.com/tips/js/event_key_codes.aspx

 

[Zapages]

The event key codes

http://www.webonweboff.com/tips/js/event_key_codes.aspx

Oh ok... Sounds good. ) Thank you.

 

[charsace]

Do you need to do what you are doing with an array? I don't know java, but couldn't you use an if not statement?

if !( variable || variable || variable...etc