Limit numbers before and after decimal point on input number - javascript

How to limit numbers for before and after the decimal point, something like 123.123 , so it can have max 3 numbers before . and max 3 numbers after .
<div class="form-group">
<input type="number" class="form-control" name="ta" id="ta" placeholder="ta" ng-model="ta.kol" ng-maxlength="15"/>
<p ng-show="taForm.kol.$error.maxlength" class="help-block">Max 15 symbols !</p>
</div>

You can add a onchange event on the input field and call a function that validates the current input value using regex and communicate same to the user.
Regex : ^[0-9]{0,3}.?[0-9]{0,3}$
JS Code to validate:
function validateNumberInput(inputNumber){
return number.search(/^[0-9]{0,3}.?[0-9]{0,3}$/) == 0 ? true : false;
}
Also you can write a directive in angular that can handle the same.

This can be solved with a simple piece of javascript if you just add an Event Listener to the input and then split the input on the decimal point you can then check the length of both parts and act accordingly.
https://jsfiddle.net/pk07net6/
function checkNumbers()
{
console.log(this.value);
var numbers = this.value.split('.');
var preDecimal = numbers[0];
var postDecimal = numbers[1];
if (preDecimal.length>3 || postDecimal.length>3)
{
alert("Max 3 numbers before and after the decimal point.")
this.select();
}
}
//ADD LISTENER TO INPUT
var input = document.getElementById("numberInput");
console.log(input);
input.addEventListener("change", checkNumbers)

You can use ng-pattern with a regex:
<input ng-pattern="/^[0-9]{1,3}(\.\d{0,3})?/" />
docs: https://docs.angularjs.org/api/ng/directive/ngPattern

For the fraction its pretty easy as you can use Angular number filter. As for the number before the digit you should create a filter like this :
app.filter('beforeDigit', function ($filter) {
return function (input) {
if (input>1000)
return (input % 1000)
elseif(input<1000)
return input;
};
});
So in the end you will end up with something like this :
{{val | filter:{number:3}, filter:beforeDigit }}

After hours of work, I create java-script function which work on keypress event. Number can be 8 characters before decimal separator and 2 character after decimal separator.
https://codepen.io/dumbelovic/pen/bvdXXq
function BeforeAfter(e, obj) {
sepDec = "."
var keycode;
var fieldval = obj.value;
if (window.event) keycode = window.event.keyCode;
else if (e) { keycode = e.which; }
else { return true; }
// denided first charatcter to be zero
if (fieldval == "" && keycode == 48)
return false;
// denided first character to be decimal point
if (fieldval == "" && (keycode == 44 || keycode == 46))
return false;
// enter first decimal point,
// but every next try to eneter decimal point return false
if (fieldval != "" && ((keycode == 44 || keycode == 46))) {
if (fieldval.indexOf(sepDec) < 0) {
var newValue = fieldval + sepDec;
$(obj).val(newValue);
}
return false;
}
var splitfield = fieldval.split(sepDec);
var beforeDecimalPoint;
var afterDecimalPoint;
if (splitfield.length == 1) {
beforeDecimalPoint = splitfield[0];
afterDecimalPoint = "";
}
else if (splitfield.length == 2) {
beforeDecimalPoint = splitfield[0];
afterDecimalPoint = splitfield[1];
}
if (beforeDecimalPoint.length == 8 && keycode != 8 && keycode != 0) {
if (obj.selectionStart >= 0 && obj.selectionStart <= 8)
return false;
}
if (afterDecimalPoint.length == 2 && keycode != 8 && keycode != 0) {
if (obj.selectionStart >= beforeDecimalPoint.length + 1 && obj.selectionStart <= beforeDecimalPoint.length + 1 + 2)
return false;
}
return true;
}

Related

Using regex to restrict input in textbox [duplicate]

This question already has answers here:
HTML input that takes only numbers and the + symbol
(7 answers)
Closed 5 years ago.
/^+{0,1}(?:\d\s?){11,13}$/ this regex allows + at first place only and numbers only...
on keypress I want user should only be able to type + at first and digits that what above regex validates But code always goes to if part..why regex not working in this scenario
function ValidatePhone(phone) {
var expr = /^\+?(?:\d\s?){11,13}$/;
return expr.test(phone);
}
var countofPlus = 0;
$("#phone").on("keypress", function (evt) {
if (evt.key == "+")
{
countofPlus = countofPlus + 1;
if (countofPlus > 1 || this.value.length >= 1) {
return false;
}
else return true;
}
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && charCode != 43 && charCode != 32 && charCode != 40 && charCode != 41 && (charCode < 48 || charCode > 57))
return false;
return true;
});
$("#phone").on("keyup", function (evt) {
debugger;
if (evt.key == "+") {
countofPlus--;
return true;
}
});
Adapting an answer from HTML input that takes only numbers and the + symbol to your use-case yields the following (IE-)compatible code:
// Apply filter to all inputs with data-filter:
var inputs = document.querySelectorAll('input[data-filter]');
for (var i = 0; i < inputs.length; i++) {
var input = inputs[i];
var state = {
value: input.value,
start: input.selectionStart,
end: input.selectionEnd,
pattern: RegExp('^' + input.dataset.filter + '$')
};
input.addEventListener('input', function(event) {
if (state.pattern.test(input.value)) {
state.value = input.value;
} else {
input.value = state.value;
input.setSelectionRange(state.start, state.end);
}
});
input.addEventListener('keydown', function(event) {
state.start = input.selectionStart;
state.end = input.selectionEnd;
});
}
<input id='tel' type='tel' data-filter='\+?\d{0,13}' placeholder='phone number'>
Above code takes copy & pasting, selecting, backspacing etc. into account where your current implementation fails.
Also, I modified the given regex to \+?\d{0,13} so it allows for incomplete input. Use HTML5 form validation to validate the final result.
I think this regex is being applied only to the char code i.e. a string of length 1. In this case regex will always fail.
Instead, try running the regex test on the input value.

Check for 4 numbers before decimal and 1 number after decimal

I have an input number field which should allow max 4 numbers before decimal and max 1 number after decimal or upto 6 numbers without decimal.
E.g. Valid 1.2, 113.5, 1234.5, 456789.
I used this RegEx ^\d{0,4}\.?(\.\d{0,1})?$ on keypress. It works fine, but gives false only after displaying the number like 113.55. How can I solve this?
My Keypress Function:
function OnKeyPress(e,DivID) {
if ( e.which != 8 && e.which != 0 && e.which != 13 && e.which != 46 && (e.which < 48 || e.which > 57)) {
return false;
}
var val = j$('[id$='+DivID+']').val();
if(DivID == 'ProximityCPPercentage')
{
var x = event.which || event.keyCode;
if(val.indexOf('.') >= 0 && e.which == 46)
return false;
else if(e.which == 46 && val.length == 3)
return false;
if(val.indexOf('.') == 0)
val = '0' + val;
if(e.which != 46)
{
strval = val + String.fromCharCode(x);
var re = /^((.|0|[1-9]\d?)(\.\d{1})?|100(\.0?)?)$/;
if(!re.test(strval))
return false;
}
}
else if(val.indexOf('.') > 0)
{
if(e.which == 46 )
return false;
var arra = val.split('.');
var decval = arra[1];
var val = arra[0];
if(val.length > 6)
return false;
if(decval.length > 0)
return false;
}
else if(e.which != 46 )
{
if(val.length > 5)
return false;
}
}
Use following regex
^\d{0,4}([.\d]\d)?$
Regex explanation here
If you don't want to match 5 digits then use negative look-ahead assertion to avoid that
^(?!\d{5}$)\d{0,4}([.\d]\d)?$
Regex explanation here
/^(?:\d{0,4}\.?(\d)|\d{0,6})?$/
NOTE: This also matches .2 and 12345 and '' (empty string). Based on your question, its not clear if you want to exclude those.
Explanation:
^ Start the line.
(?: Start a "non-capturing group".
\d{0,4} Between 0 and four digits.
\.? Zero or one literal dots.
(\d) Capture one digit. (Do you want this captured?)
| OR
\d{0,6} Zero or Six digits.
) Closes our non-capturing group (number 2).
$ End the line.
Tests:
var reg_exp = /^(?:\d{0,4}\.?(\d)|\d{0,6})?$/;
[
'1.2',
'113.5',
'1234.5',
'456789',
'12345',
'.2',
'',
'1234.',
'113.55'
].forEach(c => {
console.log('"' + c + '" tests to "' + reg_exp.test(c) + '"');
});
// "1.2" tests to "true"
// "113.5" tests to "true"
// "1234.5" tests to "true"
// "456789" tests to "true"
// "12345" tests to "true"
// ".2" tests to "true"
// "" tests to "true"
// "1234." tests to "false"
// "113.55" tests to "false"

javascript to allow only negative and positive numbers and decimal upto 6 digits on keypress

I need to validate a textbox in my cshtml page to accept only negative or positive numbers and upto 6 decimal places. This is what I have tried so far.
function AcceptUptoSixDecimalPlacesWithNegative(event, elem) {
if ((event.which != 46 || $(elem).val().indexOf('.') != -1) && (event.which < 48 || event.which > 57)) {
if (event.keyCode !== 8 && event.keyCode !== 46 && event.keyCode !== 9 && event.keyCode !== 0 && event.keyCode !== 45) { //exception
event.preventDefault();
}
}
var text = $(elem).val();
if ((text.indexOf('.') != -1) && (text.substring(text.indexOf('.')).length > 6)) {
if (event.keyCode !== 8 && event.keyCode !== 46 && event.keyCode !== 9) { //exception
event.preventDefault();
}
}
This is helping me achieve six digits after decimal point but then it allows all special characters and alphabets too.
Any help with this problem would be appreciated.
Thanks.
You could check the value with Regex:
var re = /^-?\d*\.?\d{0,6}$/;
var text = $(elem).val();
var isValid = (text.match(re) !== null);
The Regex means:
^ : beginning of string
-? : one or zero "-"
\d* : 0 to infinite numbers
\.? : 0 or 1 "."
\d{0,6} : from 0 to 6 numbers
$ : End of string
You could use the isNaN() function of JavaScript.
var inputPrevValue = "";
$(document).ready(function () {
$("#numbersOnly").change(function () {
if (isNaN($(this).val()) || $(this).val().length > 6) {
$(this).val(inputPrevValue);
} else {
inputPrevValue = $(this).val();
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<input type="text" id="numbersOnly">
This is a (very simplistic) example that tests if the input is a number less than 6 characters in length. If not, it'll revert it to the last acceptable value.
***Adding Comment as no access yet!!!
Try Regex "^[0-9]+(.[0-9]{1,2})?$" to verify the text and then proceed with logic.
js code:
var patt = new RegExp("^[0-9]+(.[0-9]{1,6})?$");
var res = patt.test(str);
if res is true then proceed else return false;
Here are a list of functions to help in your question:
Math.sign() checks if its a positive/0, negative/0 and NaN
Number MDN contains a list of number functions
parseFloat()
count digits after decimal post or regex ie. \d+([.\d{1,6}]*)\
In your context, a combination of validations in the following example:
let x = elem;
if(Math.sign(x) === 1 || Math.sign(x) === -1) && ...
// decimal validations
Hope this helps.
Don't validate the keys pressed. There are many ways to change input
value. Handle the oninput event.
You may treat the value as a string and validate using a
regular expression, but I think it's better to combine string and number-related
functions
For example:
<input type="number" step="any" oninput="validate(this)" />
function validate(input){
var number = parseFloat(input.value);
if( number == input.value && input.value.length <= number.toFixed(6).length ){ /* valid! */ }
}
http://jsfiddle.net/tto2yvwj/

JavaScript: Restricting fields - cannot remove special symbols

I am trying to restrict an input text to numbers only by checking it in a setInterval and removing the chars that are not numbers. Now so far this works relatively alright, however I am not able to remove "special symbols". For example if I input the Spanish accent symbol ' or symbols like ˇ that should be over a char, it resets the field and the value is not assigned again despite the fact that the symbol gets removed from the string (if I log the string, I can see it is).
Example:
Typing 123a => 'a' removed, input contains 123
Typing 123ˇ => input contains an empty string, despite the fact that the 'text' string
contains 123 and has a length of 3.
Typing 123 and pasting ˇ after it => ˇ removed, input contains 123
This seems like it has something to do with the fact that the special symbols are not ...self-standing (?) and need to be over a char that should be inputted next. Some ideas how to solve it?
Thank you.
I have the following HTML:
<body>
<input type="text" id="input_field">
</body>
And the JS:
$("#input_field").focus(function(e) {
console.log("got focus"+$(this).val());
var obj = this;
intID = setInterval(function() {restrictNumbers(obj)}, 10);
});
$("#input_field").blur(function(e) {
console.log("got blur")
clearInterval(intID);
});
function restrictNumbers(field) {
var text = $(field).val();
var caretPos;
var modified = false;
if(text.length > 0) {
for(var i=0; i<text.length; i++) {
if(isNaN(text.charAt(i))) {
modified = true;
caretPos = field.selectionStart - 1;
text = text.replace(text.charAt(i), "");
i--;
}
}
$(field).val(text);
if(modified) {
modified = false;
field.setSelectionRange(caretPos, caretPos);
}
}
}
JSfiddle example: http://jsfiddle.net/AvMZ5/
You can use this:-
jQuery.fn.ForceNumericOnly =
function()
{
return this.each(function()
{
$(this).keydown(function(e)
{
var key = e.charCode || e.keyCode || 0;
// allow backspace, tab, delete, arrows, numbers and keypad numbers ONLY
// home, end, period, and numpad decimal
return (
key == 8 ||
key == 9 ||
key == 46 ||
key == 110 ||
key == 190 ||
(key >= 35 && key <= 40) ||
(key >= 48 && key <= 57) ||
(key >= 96 && key <= 105));
});
});
};
You can then attach it to your control by doing:
$("#yourTextBoxName").ForceNumericOnly();
Source:- https://gist.github.com/wholypantalones/3083362

allowing input only for float number

I have pain-time when making input that only allows float number with jquery library. my code can't prevent chacacter "." when it's becoming first input, can anyone guide me to solve this problem?
$('.filterme').keypress(function(eve) {
if ( ( eve.which != 46 || $(this).val().indexOf('.') != -1 )
&& ( eve.which < 48 || eve.which > 57 )
|| ( $(this).val().indexOf('.') == 0)
)
{
eve.preventDefault();
}
});​
I use this - works for keyboard input or copy and paste
$('input.float').on('input', function() {
this.value = this.value.replace(/[^0-9.]/g, '').replace(/(\..*?)\..*/g, '$1');
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<input type="text" class="float" />
Explanation:
First regex replaces anything that's not a number or a decimal.
Second regex removes any instance of a second decimal.
I filter the first position input with the jQuery Caret plugin. Otherwise, once the dot is typed, it's already late to check where it was placed. I tried checking for the dot, then deleting the dot, but it does not look nice.
jQuery caret plugin:
http://examplet.buss.hk/js/jquery.caret.min.js
What I did:
http://jsfiddle.net/FCWrE/422/
Try it :)
$('.filterme').keypress(function(eve) {
if ((eve.which != 46 || $(this).val().indexOf('.') != -1) && (eve.which < 48 || eve.which > 57) || (eve.which == 46 && $(this).caret().start == 0)) {
eve.preventDefault();
}
// this part is when left part of number is deleted and leaves a . in the leftmost position. For example, 33.25, then 33 is deleted
$('.filterme').keyup(function(eve) {
if ($(this).val().indexOf('.') == 0) {
$(this).val($(this).val().substring(1));
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/caret/1.0.0/jquery.caret.min.js"></script>
<input type="text" class="filterme">
Regular expression would be my recommendation as well. If the value is being passed as a number and not a string you can use .toString to change it to a string and validate it with regular expression. For example:
var str = value.toString();
if(!str.match(/^-?[0-9]*[.][0-9]+$/)) {
alert("Value must be a float number");
return;
}
return value;
The above regex will match if the value passed is a floating point number. It accepts both negative and positive numbers. If you only want to accept positive numbers simply remove the '-?' from the expression. It will also fail if the value is simply zero '0' without any decimal point. If you want to accept zero simply add it as a condition to the 'if' statement.
You can use the above validation and an onchange event to prevent the user from entering a non-flot number.
Why not using Regular Expression
^[0-9]*[.][0-9]+$
Read code and test here..
You can use the following method, called on onkeypress event. Below is the HTML snippet followed by the JS method:
input type="text" onkeypress="return isNumberKey(event)" id="floor"
function isNumberKey(evt){
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode == 46){
var inputValue = $("#floor").val();
var count = (inputValue.match(/'.'/g) || []).length;
if(count<1){
if (inputValue.indexOf('.') < 1){
return true;
}
return false;
}else{
return false;
}
}
if (charCode != 46 && charCode > 31 && (charCode < 48 || charCode > 57)){
return false;
}
return true;
}
Note: The above code also ensures that you enter only single decimal in the input.
Here is my solution, works with negative numbers too (fiddle)
$("input").keypress(function (event) {
var inputCode = event.which;
var currentValue = $(this).val();
if (inputCode > 0 && (inputCode < 48 || inputCode > 57)) {
if (inputCode == 46) {
if (getCursorPosition(this) == 0 && currentValue.charAt(0) == '-') return false;
if (currentValue.match(/[.]/)) return false;
}
else if (inputCode == 45) {
if (currentValue.charAt(0) == '-') return false;
if (getCursorPosition(this) != 0) return false;
}
else if (inputCode == 8) return true;
else return false;
}
else if (inputCode > 0 && (inputCode >= 48 && inputCode <= 57)) {
if (currentValue.charAt(0) == '-' && getCursorPosition(this) == 0) return false;
}
});
function getCursorPosition(element) {
if (element.selectionStart) return element.selectionStart;
else if (document.selection)
{
element.focus();
var r = document.selection.createRange();
if (r == null) return 0;
var re = element.createTextRange(),
rc = re.duplicate();
re.moveToBookmark(r.getBookmark());
rc.setEndPoint('EndToStart', re);
return rc.text.length;
}
return 0;
}
This works for me:
var str = document.getElementById('product_'+id_product).value;
if( !str.match(/^[0-9]*([.,][0-9]+)?$/) ) {
console.log("Value must be a number or float number");
}else{
console.log("The number is valid");
}
I hope this can help someone.
Regards!

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