I have four input boxes. If the user fills the first box and clicks a button then it should autofill the remaining input boxes with the value user input in the first box. Can it be done using javascript? Or I should say prefill the textboxes with the last data entered by the user?
On button click, call this function
function fillValuesInTextBoxes()
{
var text = document.getElementById("firsttextbox").value;
document.getElementById("secondtextbox").value = text;
document.getElementById("thirdtextbox").value = text;
document.getElementById("fourthtextbox").value = text;
}
Yes, it's possible. For example:
<form id="sampleForm">
<input type="text" id="fromInput" />
<input type="text" class="autofiller"/>
<input type="text" class="autofiller"/>
<input type="text" class="autofiller"/>
<input type="button"value="Fill" id="filler" >
<input type="button"value="Fill without jQuery" id="filler2" onClick="fillValuesNoJQuery()">
</form>
with the javascript
function fillValues() {
var value = $("#fromInput").val();
var fields= $(".autofiller");
fields.each(function (i) {
$(this).val(value);
});
}
$("#filler").click(fillValues);
assuming you have jQuery aviable.
You can see it working here: http://jsfiddle.net/ramsesoriginal/yYRkM/
Although I would like to note that you shouldn't include jQuery just for this functionality... if you already have it, it's great, but else just go with a:
fillValuesNoJQuery = function () {
var value = document.getElementById("fromInput").value;
var oForm = document.getElementById("sampleForm");
var i = 0;
while (el = oForm.elements[i++]) if (el.className == 'autofiller') el.value= value ;
}
You can see that in action too: http://jsfiddle.net/ramsesoriginal/yYRkM/
or if input:checkbox
document.getElementById("checkbox-identifier").checked=true; //or ="checked"
Related
Using jquery to get the value of a textbox.
BUT
i need to enter the id of the textbox, then use that value to get the value of the textbox using jquery.
var tt = $("#fieldname").val()
that works
now how do i enter the fieldname at runtime, and get jquery to execute the val command as if it was hard coded?
There are a few ways that you could do this. One way is to listen to one of the keyboard or change events on the textbox you enter the id into, to help determine when the input has changed. So for example
$("#inputText").on("keyup", function(keyupEvent){
var textboxId = $("#inputText").val();
var textboxIdValue = $("#" + textboxId).val();
});
Or another way could be to use a click event with similar kind of logic, so for example
$("#clickMe").on("click", function(){
var textboxId = $("#inputText").val();
var textboxIdValue = $("#" + textboxId).val();
})
An example for the use case of both can be seen here https://fiddle.jshell.net/xpvt214o/114584/
Here is an example for you to get started with:
<body>
<p>Type "one" or "two" below</p>
<input id="search" />
<input id="one" value="This input is #one" />
<input id="two" value="And this is #two" />
<p id="result">No input specified</p>
</body>
And the corresponding jQuery code:
// Cache jQuery elements for performance and readability
var $search = $("#search");
var $result = $("#result");
$search.on("change", function() {
var search_value = $search.val();
if (search_value.length) {
search_value = "#" + search_value.toLowerCase().trim(); // Sanitise user input
if ($(search_value).length) {
$result.text($(search_value).val());
} else {
$result.text("Input not found");
}
} else {
$result.text("No input specified");
}
});
This will show the value of the specified input, if it exists.
You can see it in action here: https://jsfiddle.net/jeevantakhar/xpvt214o/114558/
Trying to keep a button disabled until the form fields are filled in and I cannot seem to accomplish this. I've created a small example with a single field but the principle will be the same with a larger form.
Can anyone help?
Code:
function checkForm() {
var name = document.getElementById("name").value;
var cansubmit = true;
if (name.value.length == 0) {
cansubmit = false;
}
if (cansubmit == false) {
document.getElementById("submitbutton").disabled = true;
}
};
<input type="text" id="name" onkeyup="checkForm()" />
<button type="button" id="myButton">Test me</button>
There are a couple of mistakes in your sample:
var name is assigned to the value string of the name element, then you check the value property of that - the string has no value property.
the id of the submit button is myButton so use that id to get it by id (when setting the disabled attribute).
You can disable the submitbutton until the length of the name input is greater than 0.
And disabling the button initially sounds like a good idea, right?
See corrected example below:
function checkForm()
{
var name = document.getElementById("name").value;
var cansubmit = (name.length > 0);
document.getElementById("myButton").disabled = !cansubmit;
};
<input type="text" id="name" onkeyup="checkForm()" />
<button type="button" id="myButton" disabled="disabled">Test me</button>
You might also want to consider handling change via methods other than keypress - e.g. mouseup, etc... I tried adding onchange="checkForm()" and it works but only on blur (focus-change)...
This question already has answers here:
Dynamically creating a specific number of input form elements
(2 answers)
Closed 1 year ago.
I've a form field named Number of messages, and based on what number the user specifies, I want the exact number of text fields to be dynamically generated below to allow users to enter specified number of messages.
I have browsed through some examples where JQuery is used to generate dynamic form fields, but since I'm not acquainted with JQuery, those examples are a bit too complex for me to grasp. I do know the basics of JavaScript, and would really appreciate if I could find a solution to my query using JavaScript.
function addinputFields(){
var number = document.getElementById("member").value;
for (i=0;i<number;i++){
var input = document.createElement("input");
input.type = "text";
container.appendChild(input);
container.appendChild(document.createElement("br"));
}
}
and html code will be
Number of members:<input type="text" id="member" name="member" value=""><br />
<button id="btn" onclick="addinputFields()">Button</button>
<div id="container"/>
fiddle here
You can try something similar to this...
var wrapper_div = document.getElementById('input_set');
var btn = document.getElementById('btn');
btn.addEventListener('click', function() {
var n = document.getElementById("no_of_fields").value;
var fieldset = document.createElement('div'),
newInput;
for (var k = 0; k < n; k++) {
newInput = document.createElement('input');
newInput.value = '';
newInput.type = 'text';
newInput.placeholder = "Textfield no. " + k;
fieldset.appendChild(newInput);
fieldset.appendChild(document.createElement('br'));
}
wrapper_div.insertBefore(fieldset, this);
}, false);
No. of textfields :
<input id="no_of_fields" type="text" />
<div id="input_set">
<p>
<label for="my_input"></label>
</p>
<button id="btn" href="#">Add</button>
</div>
It is a simple task which is made simpler with jQuery. You need to first get the value from the input field for which you can use .val() or .value. Once you get the value, check if it is an integer. Now, simply use .append() function to dynamically add the elements.
HTML
<form id="myForm">
Number of Messages: <input id="msgs" type="text"> </input>
<div id="addmsg">
</div>
</form>
JAVASCRIPT
$("#msgs").on('change', function()
{
var num = this.value;
if(Math.floor(num) == num && $.isNumeric(num))
{
$("#addmsg").text('');
for(var i = 0; i < num; i++)
{
$("#addmsg").append("<input type='text'/><br/>");
}
}
});
Fiddle
Note, everytime the value in the input changes, I am first clearing the div by:
$("#addmsg").text('');
And then I loop and keep adding the input field. I hope this helps!
Hi I am NewBee in Javascript. This is my second week.
Below is the code that has a form with three input fields.
The relationship of the fields is:
the second field is twice the value of the first field
the third field is the square of the first field
I have managed to do the above but i am not able to do the below :
If a user enters a value in the second or third field, the script should calculate the appropriate value in the other fields. Currently the code works well ONLY if I enter the value in the first field.
I hope I explained well in other words : how do I enter say 144 in the last textbox and the other 2 textboxes show 12 and 24 respectively. Or If I enter 24 first and first and the third text boxes show 12 and 144.
Thanks
Vipul
<html>
<head>
<script>
window.onload = init;
function init() {
var button = document.getElementById("usrButton");
button.onclick = save;
onkeyup = doMath;
function doMath(){
var base = document.getElementById("base").value;
var baseNumber_timesTwo = document.getElementById("baseNumber_timesTwo").value = (base*2);
var baseNumber_square = document.getElementById("baseNumber_square").value = (base*base) ;
}
}
</script>
</head>
<body>
<form>
<input type="text" name="base" id="base" onkeyup= "doMath()">
<br><br>
<input type="text" name="baseNumber_timesTwo" id="baseNumber_timesTwo" onkeyup= doMath()>
<br><br>
<input type="text" name="baseNumber_square" id="baseNumber_square" onkeyup= doMath()> <br><br>
</form>
</body>
</html>
take a look at the code below:
<html>
<head>
<script>
window.onload = init;
var init = function(){
var button = document.getElementById("usrButton");
button.onclick = save;
onkeyup = doMath;
}
var doMathbase = function(){
console.log('here');
var base = document.getElementById("base").value;
var baseNumber_timesTwo = document.getElementById("baseNumber_timesTwo").value = (base*2);
var baseNumber_square = document.getElementById("baseNumber_square").value = (base*base) ;
}
var doMathBase2Time = function(){
var baseNumber_timesTwo = document.getElementById("baseNumber_timesTwo").value;
var base = document.getElementById("base").value = (baseNumber_timesTwo/2);
var baseNumber_square = document.getElementById("baseNumber_square").value = (base*base) ;
}
</script>
</head>
<body>
<form>
<input type="text" name="base" id="base" onkeyup= "doMathbase()">
<br><br>
<input type="text" name="baseNumber_timesTwo" id="baseNumber_timesTwo" onkeyup= "doMathBase2Time()">
<br><br>
<input type="text" name="baseNumber_square" id="baseNumber_square" onkeyup= "doMathBaseSquare()">
<br><br>
</form>
</body>
You need to bind another function to the second and third field. I did it to the second. Now if you entered a number in the second field it return the 'base' number and the square of the base.
Try do it for the third :)
This should fit your needs:
Fiddle
//declaring those earlier saves you to get those by ID every
//time you call "doMath()" or something else
var base = document.getElementById("base");
var baseNumber_timesTwo = document.getElementById("baseNumber_timesTwo");
var baseNumber_square = document.getElementById("baseNumber_square");
function clearUp() {
base.value = "";
baseNumber_timesTwo.value = "";
baseNumber_square.value = "";
}
function doMath() {
//check which of the fields was filled
if(baseNumber_timesTwo.value){
base.value = baseNumber_timesTwo.value / 2;
}
if(baseNumber_square.value){
base.value = Math.sqrt(baseNumber_square.value);
}
//fill other fields according to that
baseNumber_timesTwo.value = (base.value*2);
baseNumber_square.value = (base.value*base.value) ;
}
As you see: There is no need to write more than one arithmetic function if you make sure that only one value is given at the time of evaluation (this is achieved by the cleanUp()
method)
However there are still some flaws in this solution! Since you are a js beginner I would suggest you to read the code and think about possible solutions for those problems as a little exercise :-)
- You cannot enter a 2 (or more) digit number in any field, why not? What do you have to change in order to allow such numbers as input?
- Why is it better (in this case!) to set the values to " " instead of '0' in the cleanUp function? Why does the code break when you try using '0' instead of "" ?
- Why does doMath() only check for values in the last two field (baseNumber_timesTwo and baseNumber_square) while ignoring the 'base' field?
Greetings, Tim
For example, if I have a form and I don't want the user to enter numbers in it and I validate it with a function containing a regular expression, how do I prevent the invalid character the user entered (in this example, a digit) from showing up in the text form if it fails the regular expression test?
This is the function I tried and the select list I tried it on (in other words, this isn't the whole program). I tried returning false to the onkeypress event handler but what the user enters into the textbox still goes through.
function noNumbers(answer) { //returns false and displays an alert if the answer contains numbers
if (/[\d]+/.test(answer)) { // if there are numbers
window.alert("You can not enter numbers in this field");
return false;
}
}
<form action="get" enctype="application/x-www-form-urlencoded">
<select id="questions" name="questions">
<option value="no_numbers">What is the name of the city where you were born?</option>
<option value="no_letters">What is your phone number?</option>
<option value="no_numbers">What is the name of your favorite pet?</option>
<option value="no_letters">What is your social security number?</option>
<option value="no_numbers">What is your mother's maiden name?</option>
</select>
<p><input type="text" name="answer" onkeypress="validateAnswer();" /></p>
</form>
This validation works great for stripping invalid characters on the fly as you enter them in the relevant field. Example:
<form id="form1" name="form1" method="post">
Email:
<input type="text" name="email" id="email" onkeyup='res(this, emailaddr);' ; </form>
<script>
var phone = "()-+ 0123456789";
var numb = "0123456789";
var alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ #-'.,";
var alphanumb = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ #-.'1234567890!?,:;£$%&*()";
var alphaname = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ,-.1234567890";
var emailaddr = "0123456789#._abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
function res(t, v) {
var w = "";
for (i = 0; i < t.value.length; i++) {
x = t.value.charAt(i);
if (v.indexOf(x, 0) != -1)
w += x;
}
t.value = w;
}
</script>
Then you would simply change the second value of the javascript call to the type of data you want entered in the field using the variables that are defined within the code.
This is the function you are looking for
function validateAnswer(src) {
var questions = document.getElementById("questions");
var rule = questions.options[questions.selectedIndex].value;
if(rule=="no_numbers") src.value = src.value.replace(/\d/g, '');
if(rule=="no_letters") src.value = src.value.replace(/\w/g, '');
}
just send the input field reference to the function and set it to onkeyup event instead:
<input type="text" name="answer" onkeyup="validateAnswer(this);" />
you should also hook the onchange event of the selectbox to reset the value of the input box. I suggest you also consider the HTML5 pattern attribute. See
the fiddle
patern attribute support
workaround for unsupported browsers
You get the key being pressed from the event object passed to the handler.
input type="text" name="answer" onkeypress="validateAnswer(this, event);" />
function validateAnswer(element, event) {
if (event.charCode) {
if (/\d/.test(String.fromCharCode(event.charCode))) {
window.alert("You can not enter numbers in this field");
return false;
}
}
}
Googling for "onkeypress event" finds many examples of this.
Make your life simpler by adding an extra parameter to your validateAnswer function like this:
<input type="text" id="answer" name="answer" onkeyup="validateAnswer(this);" />
Then you can define your validateAnswer like this:
function validateAnswer(elem){
elem.value = elem.value.replace(/[^\d]/g, '');
}
Here an example: http://jsbin.com/iwiduq/1/