Develop Reference

How to enable disable text input while making my function modular

Here is my script, what my goal is if other is selected in select, the other text input beside it will be enabled, this is what i've got so far, any approach will be really appreciated, I have 4 questions like this and I want it to be modular, best approach for doing my function to be reuseable.. How do I properly do this without any problem posting my data as 2 name inputs will generate 2 post variables in php.. T_T
<script type="text/javascript" charset="utf-8">
function validate()
{
var ddl = document.getElementById("cause_pain");
var selectedValue = ddl.options[ddl.selectedIndex].value;
if (selectedValue == "OTHER")
{
document.getElementsByClassName("causepain")[0].removeAttribute("name");
document.getElementsByClassName("causepain1")[0].removeAttribute("disabled");
}
}
</script>
<form action="test.php" method="GET">
<select class="select causepain" id="cause_pain" name="cause_pain" onchange="validate()">
<option value="" selected="selected">Select Cause of Pain</option>
<option value="ARTHRITIS">ARTHRITIS</option>
<option value="RHEUMATISM">RHEUMATISM</option>
<option value="OLD AGE">OLD AGE</option>
<option value="ACTIVE LIFESTYLE WHEN YOUNGER">ACTIVE LIFESTYLE WHEN YOUNGER</option>
<option value="OTHER">OTHER</option>
</select>
<input class="causepain1" type="text" id="cause_pain" name="cause_pain" size="40" onkeyup="clean('this.id')" disabled>
<input type="submit" id="submit"/>
</form>

This method is reusable and pretty straight forward. Using data attributes, you could specify the element that needs to be shown on the specific option element. Also before showing any input element hide the elements that were attributed to the previous selection.
Example:
<form action="test.php" method="GET">
<select class="select causepain" id="cause_pain" name="cause_pain">
<option value="" selected="selected">Select Cause of Pain</option>
<option value="ARTHRITIS">ARTHRITIS</option>
<option value="RHEUMATISM">RHEUMATISM</option>
<option value="OLD AGE">OLD AGE</option>
<option value="ACTIVE LIFESTYLE WHEN YOUNGER">ACTIVE LIFESTYLE WHEN YOUNGER</option>
<option value="OTHER" data-show="cause_pain_other">OTHER</option>
</select>
<input class="causepain1" type="text" id="cause_pain_other" name="cause_pain" size="40"
onkeyup="clean('this.id')" disabled style="display: none;">
<input type="submit" id="submit"/>
</form>
<script type="text/javascript" charset="utf-8">
var selectedOpt;
function selectionChanged(e) {
if (selectedOpt && selectedOpt.dataset.show) {
var showEl = document.getElementById(selectedOpt.dataset.show);
showEl.disabled = true;
showEl.style.display = 'none';
}
selectedOpt = this.querySelector('[value="'+e.target.value+'"]');
if (selectedOpt.dataset.show) {
var showEl = document.getElementById(selectedOpt.dataset.show);
showEl.disabled = false;
showEl.style.display = 'block';
}
}
document.querySelector('select').addEventListener('change', selectionChanged);
</script>
Your selectedOpt should be an object if you're using multiple selects on the same page and then just add the element to the object with the id as an index:
var selectedOpt = {};
...
selectedOpt[this.id] = this.querySelector('[value="'+e.target.value+'"]');

How to make one of the selected options in a drop-down list of an HTML form add a text input?

I have the following code:
<label for="city">City</label>
<select id="city" name="city" required>
<option value="">Select city</option>
<option value="city1">city1</option>
<option value="city2">city2</option>
<option value="other" onselect="">Other...</option>
</select>
I would like the form to show a new input text below this drop-down list when user chooses 'other' so that he/she can input his own city. The same way, if the user chooses back one of the existing cities in the drop-down list, the generated text input would disappear.

Add a input after the select and make it as display none
<label for="city">City</label>
<select id="city" name="city" required>
<option value="">Select city</option>
<option value="city1">city1</option>
<option value="city2">city2</option>
<option value="other" onselect="">Other...</option>
</select>
<input id="other" style="display:none" />
and inside the script tag
<script type="text/javascript">
$(document).ready(function () {
$('#city').on('change', function (e) {
var selectValue = this.value;
if (selectValue == "other") {
$("#other").show();
}
else {
$("#other").hide();
}
});
});
</script>
and you also should add Jquery in your html file before the above script tag
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
after combine the Html and Scripts your html file should look like this
<html>
<body>
<label for="city">City</label>
<select id="city" name="city" required>
<option value="">Select city</option>
<option value="city1">city1</option>
<option value="city2">city2</option>
<option value="other" onselect="">Other...</option>
</select>
<input id="other" style="display:none" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$('#city').on('change', function (e) {
var selectValue = this.value;
if (selectValue == "other") {
$("#other").show();
}
else {
$("#other").hide();
}
});
});
</script>
</body>
</html>

Vadivel's fixed code:
<script type="text/javascript">
$( document ).ready(function() {
$('#city_value').attr('type','hidden');
$('#city').change( function(){
var city=$('#city').val();
if(city=="other")
{
$('#city_value').attr('type','text');
}
else
{
$('#city_value').attr('type','hidden');
}
});
});
</script>

$('#city').live('change', function() {
var selectedCity = $(this).val();
if(selectedCity == "other"){
$('#city').after('<input type="text" id="othercity" name="othercity">');
}else{
$('#othercity').remove():
}
});

JavaScript Code:
function otherOptionCall()
{
var e = document.getElementById("city");
var einput = document.getElementById("inputother");
var strUser = e.options[e.selectedIndex].value;
if(strUser == 2)
{
einput.style.display="block";
}
else
{
einput.style.display="none";
}
}
Html code:
<label for="city">City</label>
<select id="city" name="city" required>
<option value="">Select city</option>
<option value="city1">city1</option>
<option value="city2">city2</option>
<option value="other" onselect="otherOptionCall()">Other...</option>
</select>
<input type="text" name="strother" id="inputother" style="display:none">

Use this code .
this is work fine.
You create this type use Jquery or JavaScript functions
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<body>
<div id=" " style="">
<label for="city">City</label>
<select id="city" name="city" required>
<option value="">Select city</option>
<option value="city1" onselect="city(this.val)">city1</option>
<option value="city2" onselect="city(this.val)">city2</option>
<option value="other" onselect="city(this.val)">Other...</option>
</select>
<input type="text" value="" id="city_value" placeholder="Enter City"/>
</div>
<script type="text/javascript">
$( document ).ready(function() {
$('#city_value').hide();
$('#city').change( function(){
var city=$('#city').val();
if(city=="other")
{
$('#city_value').attr('required',true);
}
else
{
$('#city_value').attr('required',false);
}
});
});
</script> </body>

JavaScript Populating an input Field Using an Html combo Box

i am trying to find a way to allow a user to click items in a combo box and have its value populate an input field and also alert "work stop" or "work start" message when appropriate option is selected. But my code is not working. Please Help!
Here is my code:
<html>
<head>
</head>
<body>
<form>
<select name="sel1" onChange="populateField(this.form)" >
<option value="">---Select---</option>
<option value="stop" >Stop</option>
<option value="start">Start</option>
</select>
<input type="text" id="eStop" name="eStop" />
</form>
<script type="text/javascript">
function populateField(frm){
test = frm.stop.value;
alert('work' test);
frm.eStop.value = test;
}
</script>
</body>
</html>
Thanks in Advance

http://jsfiddle.net/snHQY/
<form>
<select name="sel1" id="select" onchange="populateField();" >
<option value="">---Select---</option>
<option name="stop" value="stop" >Stop</option>
<option name="start" value="start">Start</option>
</select>
<input type="text" id="eStop" name="eStop" />
</form>
<script>
function populateField() {
test = document.getElementById('select').value;
alert(test);
document.getElementById('eStop').value = test;
}
</script>

You can do it using the selectedIndex if you want as well,
<form>
<select name="sel1" id="select" onchange="populateField(this);" >
<option value="">---Select---</option>
<option name="stop" value="stop" >Stop</option>
<option name="start" value="start">Start</option>
</select>
<input type="text" id="eStop" name="eStop" />
</form>
<script>
function populateField(sel) {
sel.form.eStop.value = 'work ' + (sel.selectedIndex == 1 ? 'Stop' : 'Start');
}
</script>
http://jsfiddle.net/cnpuM/

Your code has two errors. You can not reference an element by its value like this test = frm.stop.value; instead use test = frm.sel1.value; . Another error is in this line alert('work' test);. Here you are joining a string "work" with a variable "test". In java script where ever you join two or more variables or strings and variables you alway have to join them with + sign like this:alert('work ' + test);. Remaining code is ok:
<html>
<head>
</head>
<body>
<form>
<select name="sel1" onChange="populateField(this.form)" >
<option value="">---Select---</option>
<option value="stop" >Stop</option>
<option value="start">Start</option>
</select>
<input type="text" id="eStop" name="eStop" />
</form>
<script type="text/javascript">
function populateField(frm){
var test = frm.sel1.value;
alert('work '+ test);
frm.eStop.value = test;
}
</script>
</body>
</html>
You can also use selectedIndex property of "sel1" to do the same.

in your select you can add to onchange's and onkeypress to the populateField's function this as the objects reference.
<select name="sel1" onchange="populateField(this)" onkeypress="populateField(this)">
Now you can reference the select from o. to pass the selected value to the alert dialog and the input field.
function populateField(o){
alert("work " + o.value);
// use regular W3C DOM syntax for element referencing the input and populate it with the select objects selected options value
document.getElementById("eStop").value = o.value;
}

Changing one form value based on onChange of another with javascript

I can't seem to get this function to work out. I'm trying to change the "business" input value of my form based on an amount selected in the "amount" dropdown. What am I missing!!! I've been trying this for an hour.
<script type="text/javascript">
function chPy()
{
var businessvar = "paypals#ramatico.com";
if (document.forms['5'].amount.value > 11){
businessvar = "paypall#ramatico.com"
}
document.forms['5'].business.value = businessvar;
}
</script>
<form name="5">
<select name="amount" OnChange="chPy()">
<option value="na">Select</option>
<option value="1.00">$1</option>
<option value="5.00">$5</option>
<option value="10.00">$10</option>
<option value="15.00">$15</option>
<option value="20.00">$20</option>
<option value="25.00">$25</option>
</select>
<input name="business" type="text" value="">
</form>
Ok. The next step. I have about 100 of these forms on a page. Instead of creating one for each form, I'd like to have one script that changes based on which form is being changed with "onChange". Each of the forms on the page have values of the same name (but not ID) (they are for paypal). I think it will be ok if I can change the"formname" in the following: "document.forms['formname']" based on a variable populated by something like chPy("formname") etc..... I can't seem to get that to work either.

Removing the form reference would take care of both of your items.
<script type="text/javascript">
function chPy(oSelect)
{
var businessvar = "paypals#ramatico.com";
if (oSelect.form.amount.value > 11){
businessvar = "paypall#ramatico.com"
}
oSelect.form.business.value = businessvar;
}
</script>
<form name="5">
<select name="amount" OnChange="chPy(this)">
<option value="na">Select</option>
<option value="1.00">$1</option>
<option value="5.00">$5</option>
<option value="10.00">$10</option>
<option value="15.00">$15</option>
<option value="20.00">$20</option>
<option value="25.00">$25</option>
</select>
<input name="business" type="text" value="">
</form>

Problem is that you are using a number as form name.
Add some letters to the name and it will work:
<script type="text/javascript">
function chPy()
{
var businessvar = "paypals#XYZ.com";
if (document.forms['form5'].amount.value > 11){
businessvar = "paypall#XYZ.com"
}
document.forms['form5'].business.value = businessvar;
}
</script>
<form name="form5">
<select name="amount" OnChange="chPy()">
<option value="na">Select</option>
<option value="1.00">$1</option>
<option value="5.00">$5</option>
<option value="10.00">$10</option>
<option value="15.00">$15</option>
<option value="20.00">$20</option>
<option value="25.00">$25</option>
</select>
<input name="business" type="text" value="">
</form>

HTML:
<form name="form5">
<select name="amount">
<option value="na">Select</option>
<option value="1.00">$1</option>
<option value="5.00">$5</option>
<option value="10.00">$10</option>
<option value="15.00">$15</option>
<option value="20.00">$20</option>
<option value="25.00">$25</option>
</select>
<input type="text" name="business">
</form>
JavaScript:
var form5 = document.forms['form5'];
form5.amount.onchange = function() {
form5.business.value =
(this.value > 11 ? 'paypall' : 'paypals') + '#ramatico.com';
}
Live demo: http://jsfiddle.net/Fx7zh/
For multiple forms, you can use this JavaScript code:
for (var i = 0, l = document.forms.length; i < l; i++) {
document.forms[i].amount.onchange = function(i) {
this.form.business.value =
(this.value > 11 ? 'paypall' : 'paypals') + '#ramatico.com';
}
}
Live demo: http://jsfiddle.net/Fx7zh/2/

drop down options depending on the selected radio button in javascript

i have two radio buttons: in-campus and off-campus. when in-campus is selected the dropdown will have some options and when off-campus is selected there will be a different set of options. how can i do this in javascript?
i'm trying to use this. i have this code
function setInCampus(a) {
if(a == "true") {
setOptions(document.form.nature.options[document.form.nature.selectedIndex].value) }
}
function setOptions(chosen)
{
//stuff
}
it won't work. what's wrong?

First of all, make form usable and accessible even with JavaScript is disabled. Create an HTML markup that contains the dropdown lists for the radio buttons.
Then when JavaScript is enabled, hide element the dropdown elements on document load, and attach and event handler to radio buttons, so when of one them was checked, toggle visibility of the proper dropdown list.

<form>
<input type="radio" onclick="campus(0)" value="On" id="campus_on" />
<label for="campus_on" />
<input type="radio" onclick="campus(1)" value="off" />
<label for="campus_off" />
<select id="some_options">
</select>
</form>
<script>
function campus(type) {
document.getElementById('some_options').innerHTML = type ?
'<option>option 1</option><option>option 2</option>'
:
'<option>option 3</option><option>option 4</option>';
}
}
</script>

<form name="form" id="form" action="">
<input type="radio" id="radioButton1" name="radioButton" value="in-campus" />
<label for="radioButton1">in-campus</label>
<input type="radio" id="radioButton2" name="radioButton" value="of-campus" />
<label for="radioButton2">off-campus</label>
<select name="noOptions" id="noOptions" style="display: none">
<option value="Choose an Option" selected="selected">Choose an Option</option>
</select>
<select name="icOptions" id="icOptions" style="display: none">
<option value="Choose an Option" selected="selected">Choose an in-campus option</option>
<option value="icOption1">in-campus option 1</option>
<option value="icOption2">in-campus option 2</option>
</select>
<select name="ocOptions" id="ocOptions" style="display: none">
<option value="Choose an Option" selected="selected">Choose an off-campus option</option>
<option value="ocOption1">off-campus option 1</option>
<option value="ocOption2">off-campus option 2</option>
</select>
<select name="allOptions" id="allOptions" style="display: block">
<option value="Choose an Option" selected="selected">Choose an Option</option>
<option value="icOption1">in-campus option 1</option>
<option value="icOption2">in-campus option 2</option>
<option value="ocOption1">off-campus option 1</option>
<option value="ocOption2">off-campus option 2</option>
</select>
</form>
<script>
window.document.getElementById("noOptions").style.display = "block";
window.document.getElementById("allOptions").style.display = "none";
function changeOptions() {
var form = window.document.getElementById("form");
var icOptions = window.document.getElementById("icOptions");
var ocOptions = window.document.getElementById("ocOptions");
window.document.getElementById("noOptions").style.display = "none";
if (form.radioButton1.checked) {
ocOptions.style.display = "none";
icOptions.style.display = "block";
icOptions.selectedIndex = 0;
} else if (form.radioButton2.checked) {
icOptions.style.display = "none";
ocOptions.style.display = "block";
ocOptions.selectedIndex = 0;
}
}
window.document.getElementById("radioButton1").onclick = changeOptions;
window.document.getElementById("radioButton2").onclick = changeOptions;
</script>

Radio buttons can have an onClick handler.
<INPUT TYPE="radio" NAME="campustype" VALUE="incampus" onClick="setInCampus(true)">in-campus
<INPUT TYPE="radio" NAME="campustype" VALUE="offcampus" onClick="setInCampus(false)">off-campus

You could just define both 's in the code, and toggle visibility with javascript.
Something like this:
<html>
<head>
<script type="text/javascript">
function toggleSelect(id)
{
if (id == 'off')
{
document.getElementById('in-campus').style['display'] = 'none';
document.getElementById('off-campus').style['display'] = 'block';
}
if (id == 'in')
{
document.getElementById('off-campus').style['display'] = 'none';
document.getElementById('in-campus').style['display'] = 'block';
}
}
</script>
</head>
<body>
<select id='in-campus'>
<option>a</option>
</select>
<select id='off-campus' style='display: none;'>
<option>b</option>
</select>
<br />
<input type='radio' name='campustype' value='in' onclick="toggleSelect('in');" checked='1' /><label for='incampus'>In-campus</label><br />
<input type='radio' name='campustype' value='off' onclick="toggleSelect('off');" /><label for='offcampus'>Off-campus</label>
</body>
</html>
A prettier variant of this approach would not require support for javascript, it would gracefully fallback on basic html.

if you need to fetch the options from a database or something, you might consider using AJAX.

<html>
<head>
<script language="javascript">
var current = false;
function onChange()
{
var rad = document.getElementById("radIn").checked;
if(rad == current)
return;
current = rad;
var array = rad ? ["in1","in2","in3","in4","in5"] :
["out1","out2","out3","out4","out5"];
var sel = document.getElementById("dropDown");
sel.innerHTML = "";
var opt;
for each(var k in array)
{
//alert(k + " asdsd");
opt = document.createElement("option");
opt.innerHTML = k;
sel.appendChild(opt);
}
}
</script>
</head>
<body onload="onChange();">
<input type="radio" value="in" name="campus" onclick="onChange()"
id="radIn" checked="true"/>
<label for="radIn">In Campus</label>
<br/>
<input type="radio" value="out" name="campus" onclick="onChange()"
id="radOut"/>
<label for="radOut">Out Campus</label>
<br/>
<select id="dropDown"/>
</body>
</html>