Develop Reference

Stop form whitespace when user pressing submit

Okay, so I have a form. Applied a function to it.
All I want to do is when the form is submitted it launches the function, it checks to see if there is white space and throws out a message. I have the following:
function empty() {
var x;
x = document.getElementById("Username").value;
if (x == "") {
alert("Please ensure you fill in the form correctly.");
};
}
<input type='submit' value='Register' onClick='return empty()' />
<input type='text' id="Username" />
This is fine for if someone pressed the space-bar once and enters one line of whitespace, but how do I edit the function so that no matter how many spaces of whitespace are entered with the space-bar it will always throw back the alert.
Thanks in advance. I am very new to JavaScript. So please be gentle.

Trim the string before testing it.
x = document.getElementById("Username").value.trim();
This will remove any whitespace at the beginning and end of the value.

I have made a function for the same, i added another checks (including a regular expresion to detect multiples empty spaces). So here is the code:
function checkEmpty(field){
if (field == "" ||
field == null ||
field == "undefinied"){
return false;
}
else if(/^\s*$/.test(field)){
return false;
}
else{
return true;
}
}
Here is an example working with jquery: https://jsfiddle.net/p87qeL7f/
Here is the example in pure javascript: https://jsfiddle.net/g7oxmhon/
Note: the function checkEmpty still be the same for both

this work for me
$(document).ready(function() {
$('#Description').bind('input', function() {
var c = this.selectionStart,
r = /[^a-z0-9 .]/gi,
v = $(this).val();
if (r.test(v)) {
$(this).val(v.replace(r, ''));
c--;
}
this.setSelectionRange(c, c);
});
});
function checkEmpty(field) { //1Apr2022 new code
if (field == "" ||
field == null ||
field == "undefinied") {
return false;
} else if (/^\s*$/.test(field)) {
return false;
} else {
return true;
}
}

How to change the value of an active text input using Javascript?

I am trying to make a form with a date input.
However, this input is in date format, and I would like to change the value while the control is still active.
Here is the full code :
// Javascript code
function add_value()
{
var dataoriginale = document.getElementById("fin_mater").value;
if(document.getElementById("fin_mater").value.length = 2)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
else if(document.getElementById("fin_mater").value.length = 5)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
}
<!-- Code of the input -->
<input id="fin_mater" type="text" onchange="add_value();" name="fin_mater" maxlength="10" placeholder="DD-MM-YYYY"/>
But this is only updating the text when you exit of the control, and I would like to know how to run this javascript function while the control is still active.
Thanks.

You need to use onkeyup.
<input id="fin_mater" type="text" onkeyup="add_value();" name="fin_mater" maxlength="10" placeholder="DD-MM-YYYY"/>
From the docs
Execute a JavaScript when a user releases a key
Also in your if your are using =, you should be using ==
...
if(document.getElementById("fin_mater").value.length == 2)//==
...
else if(document.getElementById("fin_mater").value.length == 5)
...

First let's make the code smell more like the "javascript" :)
// Javascript code
function $(id) {
return document.getElementById(id);
}
function add_value(event) {
var dataOriginale = $("fin_mater").value,
len = dataOriginale.length,
key = event.keyCode || event.charCode;
// Allow BACKSPACE and DEL
if (key === 8 || key === 46) {
return true;
}
if(len === 2 || len === 5) {
$("fin_mater").value = dataOriginale + '-';
}
return false;
}
<!-- Code of the input -->
<input id="fin_mater" type="text" onKeyUp="add_value(event);" name="fin_mater" maxlength="10" placeholder="DD-MM-YYYY"/>
If you want to append the "-" automatically when you input numbers, you can listen on the "onKeyUp" event of the text box rather than the "onchange".
PS: You can use the key code to limit only numbers input and also do some validations.

You can use keypress():
$(document).ready(function()
{
$( "#fin_mater" ).keypress(function() {
var dataoriginale = document.getElementById("fin_mater").value;
if(document.getElementById("fin_mater").value.length == 2)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
else if(document.getElementById("fin_mater").value.length == 5)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
});
});
Fiddle

With some of your help and some documentation, I finally went to this, that works perfectly on every browser that supports javascript.
$(document).ready(function(event)
{
$( "#fin_mater" ).keypress(function(event) {
var dataoriginale = document.getElementById("fin_mater").value;
if(event.keyCode != 8)
{
if(document.getElementById("fin_mater").value.length == 2)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
else if(document.getElementById("fin_mater").value.length == 5)
{
document.getElementById("fin_mater").value=dataoriginale+'-';
}
}
});
});
Thanks everyone !

Html input validation [duplicate]

Ok basically when I type , it won't allow it.
I want to add more like < > / \ etc how do I do it?
$("#in1").keypress(function (evt) {
if (String.fromCharCode(evt.which) == ",")
return false;
});
<input type="text" id="in1">
Can see the demo here. http://jsfiddle.net/QshDd/38/

If you have a list of disallowed characters, you can forbid them in this fashion:
$("#in1").keypress(function (evt) {
return [',', '<', '>', ].indexOf(String.fromCharCode(evt.which)) === -1;
});

its working , you Required to give more conditions:
$("#in1").keypress(function (evt) {
if (String.fromCharCode(evt.which) == ",")
return false;
if (String.fromCharCode(evt.which) == "<")
return false;
if (String.fromCharCode(evt.which) == ">")
return false;
if (String.fromCharCode(evt.which) == "\\")
return false;
});
Another Solution , either use regEx or use XMLParser or JSON parser methods.

if you want something like this
<input type="text"> ===> input typetext
$("#in1").keypress(function (evt) {
if (isValid(String.fromCharCode(evt.which)))
return false;
});
function isValid(str){
return /[~`!#$%\^&*+=\-\[\]\\';,/{}|\\":<>\?]/g.test(str);
}
http://jsfiddle.net/QshDd/61/

Try this, if you need only alphabets
$("#in1").keypress(function (evt) {
var expr = /^([a-zA-Z\s]+)$/i;
if (!String.fromCharCode(evt.which).match(expr))
return false;
});

var chars = new Array("<", ">" ,"/" ,"\\");
$("#in1").keypress(function (evt) {
if(!(chars.indexOf(String.fromCharCode(evt.which)) > -1))
return false;
});

append a url typed into a input text field to an anchor then allow users to click on it and follow the url they typed

I want to have a text field where people can type in a value. Then I want to have a href open the url they typed.
Very similar to this fiddle but I want the href to be only the input value that the users typed.
Fiddle:
http://jsfiddle.net/BMDKr/
Link Text
<input type="text" id="appendUrl" />
$(function() {
$('#baseUrl').click( function() {
window.location = $(this).attr('href') + '/' + $('#appendUrl').val();
return false;
});
});

Edit: To answer your question if they typed an external URL, you're going to use the function found here: Fastest way to detect external URLs?
function isExternal(url) {
var match = url.match(/^([^:\/?#]+:)?(?:\/\/([^\/?#]*))?([^?#]+)?(\?[^#]*)?(#.*)?/);
if (typeof match[1] === "string" && match[1].length > 0 && match[1].toLowerCase() !== location.protocol) return true;
if (typeof match[2] === "string" && match[2].length > 0 && match[2].replace(new RegExp(":("+{"http:":80,"https:":443}[location.protocol]+")?$"), "") !== location.host) return true;
return false;
}
In combination with out current code, that makes:
function isExternal(url) {
var match = url.match(/^([^:\/?#]+:)?(?:\/\/([^\/?#]*))?([^?#]+)?(\?[^#]*)?(#.*)?/);
if (typeof match[1] === "string" && match[1].length > 0 && match[1].toLowerCase() !== location.protocol) return true;
if (typeof match[2] === "string" && match[2].length > 0 && match[2].replace(new RegExp(":("+{"http:":80,"https:":443}[location.protocol]+")?$"), "") !== location.host) return true;
return false;
}
$(function () {
// When the input field changes value
$('#text').blur(function(){
// Check if the link is external:
if(isExternal($('#text').val())){
// Set the attribute 'href' of the link to the value of the input field
$('#link').attr('href', $('#text').val());
}
else
{
// Show an error if it's not external
alert('Link is not external!');
}
});
});
<input type="text" id="text"> Link
Fiddle: http://jsfiddle.net/BMDKr/6/

Adding an if statement inside if statement

I have a function for a button which submits a form. This function checks to see if the 5 checkboxes are selected #co1,#co2,#co3,#div1,#cc1.
It then also checks to see if tcaccept select is set to 1.
If so the form submits, else the alert pops up.
This is the code i have at the moment:
$('#submit2pd').click(function(event) {
var $finishBoxes = $('#co1,#co2,#co3,#div1,#cc1');
if (!($finishBoxes.length == $finishBoxes.filter(':checked').length && $('#tcaccept').val() == '1' )) {
alert('Please complete the Induction Checklist confirming that you have read and understood the Colleges main policies and procedures, agreeing to comply with these in line with the terms of your contract with the College');
return false;
}
// otherwise the form is submitted
window.location.href = "submit2pd.php";
});
All works brilliantly, but i want to add to this line as i have another option that is required. But this needs to be an if statement.
if (!($finishBoxes.length == $finishBoxes.filter(':checked').length && $('#tcaccept').val() == '1' && THE IF STATEMENT))
this is what i need to incorporate into the if statement above.
if ($("#ctl").val() == "1") {
$('#ctlapp') must not be blank
}
else if ($("#ctl").val() == "0") {
$('#ctlapp') can be blank
}
Any help would be greatly appreciated.

How about:
if (!($finishBoxes.length == $finishBoxes.filter(':checked').length &&
$('#tcaccept').val() == '1' &&
!($("#ctl").val() == "1" && $('#ctlapp').val() === "")))
What we're adding here is another condition which says, "And make sure it's not the case that #ctl is 1, and #ctlapp is blank".
Edit: and please see my comment above - your question is not about jQuery, forms, or validation. It's barely about JS.

if($('#tcaccept').val() == '1' && validate()) {
// do something
}
var validate = function(){
if ($("#ctl").val() == "1") {
$('#ctlapp') must not be blank
return false;
}
else if ($("#ctl").val() == "0") {
$('#ctlapp') can be blank;
return true;
}
return true;
}

I'd say clean up the code a little, and things will get a bit simpler:
$('#submit2pd').click(function(event) {
var fail_message = 'Please complete the Induction Checklist confirming that you have read and understood the Colleges main policies and procedures, agreeing to comply with these in line with the terms of your contract with the College',
$finishBoxes = $('#co1,#co2,#co3,#div1,#cc1'),
$checkedBoxes = $finishBoxes.filter(':checked'),
tcaccept = $('#tcaccept').val(),
ctl = $("#ctl").val(),
ctlapp = $('#ctlapp').val();
if (tcaccept == '1' && $finishBoxes.length != $checkedBoxes.length ) {
alert( fail_message );
return false;
} else if( ctl == "1" && ctlapp == "" ) {
alert( "some other message" );
return false;
}
// otherwise the form is submitted
window.location.href = "submit2pd.php";
});
I left the test for $('#ctl').val() == "0" out because it sounds like that's the only other value it can have, and there's no validation that needs to take place if it is "0".

Use a logic or || to capture both constalations:
$("#ctl").val() == "1" && $('#ctlapp') != ""
OR
$("#ctl").val() == "0"
if (
!(
$finishBoxes.length == $finishBoxes.filter(':checked').length
&&
$('#tcaccept').val() == '1'
&&
(
($("#ctl").val() == "1" && $('#ctlapp') != "")
||
$("#ctl").val() == "0"
)
)
)