Update Textbox with Combobox value on ValueChange event - javascript

My ultimate goal with this is to make a dropdown that allows user input also. The best I can seem to do is an textbox next a dropdown that makes it look like they are similar, the issue I am running into is that I need the textbox to update whenever my dropdown value is changed. I have some code I've been playing with (below), but it doesn't seem to be getting me anywhere! Any pointers on how I can get this to work, or am I messing up the syntax? (fairly new to both jscript and html)
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<style type="text/css">
select
{
width:200px;
}
</style>
<head>
<title>Test</title>
<script type="text/JavaScript">
var select = document.getElementById('theItems');
var input = document.getElementById('stroke');
function otherSelect()
{
input.value = select.value;
}
</script>
</head>
<body>
<form action="" method="">
<input name="stroke"/>
<select name="theItems" onchange="otherSelect()">
<option value="item1">Item One</option>
<option value="item2">Item Two</option>
<option value="item3">Item Three</option>
<option value="item3">Item Four</option>
<option value="other">Other</option>
</select>
<div id="otherBox" style="visibility: hidden;">
If other: <input name="otherField" type="text" />
</div>
</form>
</body>

You should execute your script in the window.onload event. The elements are not available to your script when it is being executed. Change your script to this
<script type="text/JavaScript">
window.onload = function(){
var select = document.getElementById('theItems');
var input = document.getElementById('stroke');
function otherSelect()
{
input.value = select.value;
}
}
</script>
This way the script will be executed after the HTML elements have been rendered by the browser.

Here's a simple pure JavaScript implementation of what you want. http://jsfiddle.net/24Xhn/
We're going to setup the markup so the select box and the other input box have similar name and id attributes. We'll use classes to setup/initialize the onchange events and make sure the inputs start off hidden and disabled. By toggling the "disabled" attribute, true or false we are making it so the input or select don't show up when the form is submitted, submit the form in the JSFiddle with different combinations and you'll see the output in the query string of the URL.
HTML
<select id="items1" name="items1" class="select-other">
<option value="item1">Item One</option>
<option value="item2">Item Two</option>
<option value="item3">Item Three</option>
<option value="item3">Item Four</option>
<option value="other">Other</option>
</select>
<input id="items1-other" name="items1-other" class="input-other" />
JS
// setup
var inps = document.getElementsByClassName("input-other");
for(var i=0; i<inps.length; i++) {
var inp = inps[i];
// hide & disable the "other" input
inp.style.display = "none";
inp.disabled = true;
// set onchange, if input is empty go back to select
inp.onchange = function() {
var val = this.value;
if(val == "") {
this.style.display = "none";
this.disabled = true;
// get its associated select box
var sel = document.getElementById(this.id.replace(/-other$/i, ""));
sel.style.display = "";
sel.disabled = false;
}
};
}
var sels = document.getElementsByClassName("select-other");
for(var i=0; i<sels.length; i++) {
var sel = sels[i];
// set onchange if value is other switch to input
sel.onchange = function() {
var val = this.value;
if(val == "other") {
this.style.display = "none";
this.disabled = true;
// get associated input box
var inp = document.getElementById(this.id + "-other");
inp.style.display = "";
inp.disabled = false;
}
};
}

I just realized what was wrong. I didn't truly look at the html until I copied and pasted it into a test application and I figured out the issue.
You need to set the id tag to the stroke and theItems not the name tag. That's why it's not doing anything. There was, I'm guessing, a copy/paste issue as well because you didn't have a closing html tag, but I assumed you just missed copying that. Also, you don't really need global variables in order to retrieve the input and select you just need them inside the actual function, and you can actually pass the select into the function like so.
Your code corrected:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<style type="text/css">
select
{
width:200px;
}
</style>
<script type="text/javascript">
function otherSelect(obj)
{
var input = document.getElementById('stroke');
input.value = obj.value;
}
</script>
</head>
<body>
<form action="" method="">
<input id="stroke" name="stroke"/>
<select id="theItems" name="theItems" onchange="otherSelect(this)">
<option value="item1">Item One</option>
<option value="item2">Item Two</option>
<option value="item3">Item Three</option>
<option value="item3">Item Four</option>
<option value="other">Other</option>
</select>
<div id="otherBox" style="visibility: hidden;">
If other: <input name="otherField" type="text" />
</div>
</form>
</body>
</html>

I also wanted to create a combobox with an auto-updating text field next to it for new entries, and came up with this in less than an hour, based on simple html and javascript examples from w3schools.com. It works perfectly on my IE browser.
<!DOCTYPE html>
<html>
<head>
<script>
function updateField(name, value)
{
document.getElementById(name).value = value;
}
</script>
</head>
<body>
<select name='10' onchange='updateField(this.name, this.value)'>
<option value='volvo'>Volvo</option>
<option value='saab'>Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<input type="text" id="10" value="volvo">
</body>
</html>

Related

Post Select Options To Database When "other" field is selected

i'm using the code below to display an input field when "other" option is selected.
It works perfectly when "other" is selected.
However, i am unable to post to database when any other option apart from "other" is selected.
The problem is the text input negates the select options.
Any idea how to go about this?
There's a question that attempts to solve the problem but i don't have enough reputation to comment Stackoverflow.com/questions/9634783/how-to-activate-a-textbox-if-i-select-an-other-option-in-drop-down-box
<html>
<head>
<script type="text/javascript">
function CheckColors(val){
var element=document.getElementById('color');
if(val=='pick a color'||val=='others')
element.style.display='block';
else
element.style.display='none';
}
</script>
</head>
<body>
<select name="color" onchange='CheckColors(this.value);'>
<option>pick a color</option>
<option value="red">RED</option>
<option value="blue">BLUE</option>
<option value="others">others</option>
</select>
<input type="text" name="color" id="color" style='display:none;'/>
</body>
</html>
the problem is, that you have multiple form elements with the same name. This might work in some cases, but generally is a bad practice. Name them differently and let the code that processes the input handle the data.
If you really need an input with the name 'color' that holds the current color, here is a solution that should work:
function checkColors(val) {
var element = document.getElementById('color');
if (val == 'pick a color' || val == 'others') {
element.style.display = 'block';
} else {
element.value = val; //make sure element always has the right value;
element.style.display = 'none';
}
}
<html>
<head>
</head>
<body>
<select name="colorSelect" onchange='checkColors(this.value);'>
<option>pick a color</option>
<option value="red">RED</option>
<option value="blue">BLUE</option>
<option value="others">others</option>
</select>
<input type="text" name="color" id="color" style='display:none;' />
</body>
</html>

I want change text of Select box without disturbing "option" tag values

I want to show specific text in select box without changing/removing text/value of option tag. e.g. When user selects "+91 India" I want to show only "+91"
function countryChange() {
//some code
document.getElementById('mySelect').value = 'some value';
}
<!DOCTYPE html>
<html>
<body>
<select id="mySelect" onChange="countryChange()">
<option value="+91">+91 India</option>
<option value="+45">+45 Denmark</option>
</select>
</body>
</html>
This is the way you can do this
To be honest I do not think that what you are trying to do is a good idea. I would recommend creating some div and changing its content.
var select = document.getElementById('mySelect'),
options = select.options;
select.onchange = function() {
var option = options[select.selectedIndex];
option.text = option.value;
select.blur();
}
select.onfocus = function() {
for (i = 0; i < options.length; i++) {
options[i].text = options[i].getAttribute("data-text");
}
}
<!DOCTYPE html>
<html>
<body>
<select id="mySelect">
<option value="+91" data-text="+91 India">+91 India</option>
<option value="+45" data-text="+45 Denmark">+45 Denmark</option>
</select>
</body>
</html>

Activate text box if the "Other" option is selected and POST data

I found this code on another entry on here which works fine except the text field overwrites with nothing if a colour is selected form the select box so nothing is sent in the POST. Can anyone help?
<html>
<head>
<script type="text/javascript">
function CheckColors(val){
var element=document.getElementById('color');
if(val=='pick a color'||val=='others')
element.style.display='block';
else
element.style.display='none';
}
</script>
</head>
<body>
<select name="color" onchange='CheckColors(this.value);'>
<option>pick a color</option>
<option value="red">RED</option>
<option value="blue">BLUE</option>
<option value="others">others</option>
</select>
<input type="text" name="color" id="color" style='display:none;'/>
</body>
</html>
Thanks,
John
It looks like you need to set the selected color to the text box
in the Javascript section, change this:
if(val=='pick a color'||val=='others'){ //Always use curly brackets
element.style.display='';
element.value = '';
}
else {
element.style.display='none';
element.value = val;
}

More Properties of Dropdown options

I've got a dropdown setup going on in which the user enters an input value, chooses a calculation to perform on that number from a dropdown, then a function displays the result.
What I would like is to add more 'values' to the dropdown, so when an option is selected from the list, it can also, say, display some text stored in the list, or some other information. Right now I can return the selected option's value (.value) and use the option's name (.text) to perform functions, but is there any more data I can add to each selection to be used later?
<html>
<head>
<script language="JavaScript">
function myfunction(form)
{
var i = parseFloat(form.Input.value, 10);
var e = document.getElementById("calculationList");
var strUser = e.options[e.selectedIndex].value;
form.Output.value = strUser*i;
}
</script>
</head>
<body>
<form>
Input Number:
<INPUT NAME="Input" SIZE=15>
Make a selection:
<select id="calculationList" onchange="myfunction(form)">
<option></option>
<option value="2">Double It</option>
<option value="3">Triple It</option>
<option value="10">Multiply It By ten</option>
</select>
Output Number:
<INPUT NAME="Output" SIZE=15>
</FORM>
</body>
</html>
Basically you may attach data attribute to your options like that:
<select id="calculationList">
<option></option>
<option value="2" data-aaa="10">Double It</option>
<option value="3" data-aaa="20">Triple It</option>
<option value="10" data-aaa="30">Multiply It By ten</option>
</select>
And later get the content of the attribute:
var dropdown = document.getElementById("calculationList");
dropdown.addEventListener("change", function() {
console.log(dropdown.options[dropdown.selectedIndex].getAttribute("data-aaa"));
});
jsfiddle -> http://jsfiddle.net/pzKrr/
Edit:
If you want to implement my solution remove onchange="myfunction(form)" from the select tag. After that add the following code just after that myfunction
window.onload = function() {
var dropdown = document.getElementById("calculationList");
dropdown.addEventListener("change", function() {
console.log(dropdown.options[dropdown.selectedIndex].getAttribute("data-aaa"));
});
};

HTML select dropdownlist with javascript function

This is how far I got:
<head>
<script type="text/javascript">
function showonlyone(thechosenone) {
var article = document.getElementsByTagName("div");
for(var x=0; x<article.length; x++) {
name = article[x].getAttribute("name");
if (name == 'article') {
if (article[x].id == thechosenone) {
article[x].style.display = 'block';
}
else {
article[x].style.display = 'none';
}
}
}
}
</script>
</head>
<form>
<select>
<option SELECTED>Choose one</option>
<option value="javascript:showonlyone(id1)">First</option> <!-- That's probably wrong -->
<option value="javascript:showonlyone(id2)">Second</option>
</select>
</form>
<div name="article" id="id1" style="display:none;">
First one selected
</div>
<div name="article" id="id2" style="display:none;">
Second one selected
</div>
Here is what it should do:
Create a dropdownlist (with 3 Values)
If you click on "First" it should only show the of the content of <div id="id1">
If you click on "Second" it should only show the of the content of <div id="id2">
I know that this can't work like this. But I do not know how I can get this working.
There might be a easier way than this javascript function but it has to be this way.
Thank you for your help
Use a onchange event handler instead:
Update your <select> to <select onchange="showonlyone(this)">.
Change your <option> values to only the IDs - not JavaScript calls.
Update your JavaScript to accept the HTMLSelectElement (which will be passed-in by the this, above). (Yes, you were correct here.)
From the chosen HTMLSelectElement, ask it for its value.
Here is a fixed, working version: http://jsfiddle.net/YRF6u/
Also included here:
<head>
<script type="text/javascript">
function showonlyone(selector) {
var thechosenone = selector.value;
var article = document.getElementsByTagName("div");
for(var x=0; x<article.length; x++) {
name = article[x].getAttribute("name");
if (name == 'article') {
if (article[x].id == thechosenone) {
article[x].style.display = 'block';
}else{
article[x].style.display = 'none';
}
}
}
}
</script>
</head>
<form>
<select onchange="showonlyone(this)">
<option SELECTED>Choose one</option>
<option value="id1">First</option>
<option value="id2">Second</option>
</select>
</form>
<div name="article" id="id1" style="display:none;">
First one selected
</div>
<div name="article" id="id2" style="display:none;">
Second one selected
</div>
I would not consider this production-ready code, but it should be sufficient enough to solve your current round of questions.

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