jQuery event on select elements when an option is selected (NOT .change) - javascript

Looking for an easy event to bind to that will fire any time an option is selected, even when it is the currently selected option. jQuery's .change() does not seem to fire when selecting the selected option again, but only the others (which makes sense, because it is a "change" event after all).
Is there anything else out there that is more or less identical to how change works, but will also fire when the selected element is selected again? Or will I need to get sloppy with click events or something?

<select id="select">
<option value="1">1</option>
<option value="2">2</option>
</select>
JS
$(function(){
$('#select option').click(function(){
alert($(this).val());
});
})

While Irfan's solution seems like a viable one, it did not work for me in Chrome. However, I ended up using a sort of workaround to solve this problem where I set a placeholder type option when the click event fires on the select box.
<select id="dropdown">
<option value="choose" disabled selected>Choose</option>
<option value="1">1</option>
<option value="2">2</option>
</select>
<script>
// When the dropdown is opened, the "choose" option is selected
$('#dropdown').on('click', function(){
$("#dropdown option").filter(function() {
return $(this).val() == "choose";
}).prop('selected', true);
// On change will always fire
$('#dropdown').on('change', doStuff);
});
function doStuff(){
// Grab the selected value before click changes it
let currentValue = $('#dropdown').val();
alert(currentValue);
/* Do other stuff with currentValue
Wait until second click that selects sets value to "choose"
when the user makes their selection, then set the selector
back to what the user chose
*/
setTimeout(function(){
$("#dropdown option").filter(function() {
return $(this).val() == order;
}).prop('selected', true);
}, 100);
}
</script>
The result is a slight delay before the selector shows what the user chose, but the change event always fires, since the active value was changed. This doesn't work as well in IE or FireFox, but if you can detect the browser being used, and combine this with Ifran's solution, you should be able to have this working on all browsers.

This is how I just solved a similar problem. Needed to display other fields when certain option was chosen. put the onclick on the select and passed the value of the option. Then just target the specific option you want in the function.
<select onclick='myfunc($(this).val())'>
<option value="" selected disabled hidden>pick</option>
<option value="a">a</option>
<option value="b">b</option>
</select>
Jquery
function myfunc(val){
if(val == 'a'){
$("#a").show();
$("#b").hide();
}
if(val=='b'){
$("#a").hide();
$("#b").show();
}
}

Related

change event of dropdown unable to trigger

I have a dropdown. On its select, the change event is fired. I again select the same element from the dropdown, it does not bind the change event to it.
One possible workaround is with click() event like the following:
var prevVal = "";
$('#mySelect').click(function(){
if($(this)[0].selectedIndex > 0){
var currVal = $(this).val();
if(prevVal != currVal){
console.log(currVal);
prevVal = currVal;
}
else prevVal = "";
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="mySelect">
<option value="select">Please Select</option>
<option value="Arabic">Arabic</option>
<option value="Spanish">Spanish</option>
<option value="English">English</option>
</select>
Once option is selected from drop down, change event is not triggered on same option as there is no change with the selected value.
You can use click or focusout event, as per use.
Assuming your attached image is describing a language switch. At first select, the system will change content to Spanish.
At the second click for spanish nothing will happen since the Spanish is already selected at the first click. - The details of what happens in the logic of your solution is unknown to us.

Getting the value of a select button html/js

So I am trying to get the user input(value) of this select option button. Everything I look at online dosen't really tell me how to get this button value so I can use it and manipulate it, please help
You need a click event listener for this.
This code snippet demonstrate what you need to do:
// Get Select List
var favAnimal = document.getElementById("favAnimal");
// Add event Listener for any change in the selection
favAnimal.addEventListener("change", function() {
if (favAnimal != undefined && favAnimal.value != "Choose"){
//Do actions on selected option
console.log(favAnimal.value)
}
});
<select id="favAnimal">
<option value="Choose">choose</option>
<option value="Lion">Lion</option>
<option value="Shark">Shark</option>
<option value="Eagle">Eagle</option>
</select>
Given a select with some options
<select id="favAnimal">
<option value="Choose">Choose</option>
<option value="lion">Lion</option>
...
</select>
To get the value of the select you do it like this
var favAnimal = document.getElementById("favAnimal");
console.log(favAnimal.value);

Javascript: "change" event not triggered when using the keyboard on a html select element in Firefox

If you have a select:
<select id="sel">
<option value="A">option A</option>
<option value="B">option B</option>
<option value="C">option C</option>
</select>
And you focus the select and then use the arrows to change the selected option, Firefox 30 will not trigger the "change" event on that select. This is how FF chose to implement the "change" event and they said it won't be fixed (it seems that this is what the standard says).
To try to get around this problem we can register the handler for both "change" and "keyup" events so we get the event even when the user uses the keyboard:
sel.addEventListener("change", handle_change);
sel.addEventListener("keyup", handle_change);
Except now we run into another bug http://jsfiddle.net/xLCNX/ that will appear when the user uses both the mouse and the keyboard to select options (use mouse to select option B, use keyboard to select option C, use again mouse to select option B - no change event will be triggered for this last action).
To solve this problem what you need to do is to put this in the event handler:
sel.value = sel.value;
Code from fiddle:
HTML:
<ol>
<li>with the mouse(!) select option <b>B</b>. Event <b>change</b> is triggered.</li>
<li>keyboard(!) press down arrow to select option <b>C</b>. Event <b>keyup</b> is triggered.</li>
<li>with the mouse(!) select option <b>B</b> again. No event is triggered<br>
Because we have selected the same option that was previously selected (<b>B</b>), there is no change so FF will not trigger a <b>change</b> event.<br>
When we select option <b>C</b> with the keyboard, only the displayed option and the <b>select.value</b> changed to option <b>C</b>. Somehow, internally, FF kept the original value, option <b>B</b>. So when we selected back option <b>B</b> FF decides that nothing changed. The problem is the inconsistency between what FF knows is the current value and the other two values: the displayed value and the <b>select.value</b> value.
</li>
</ol>
<select id="sel">
<option value="A">option A</option>
<option value="B">option B</option>
<option value="C">option C</option>
</select>
<ol id="log"></ol>
JS:
var handle_change = function() {
log.innerHTML += "<li>option " + sel.value + "</li>";
//uncomment this to fix the bug
//sel.value = sel.value;
};
var sel = document.getElementById("sel");
var log = document.getElementById("log");
sel.addEventListener("change", handle_change);
sel.addEventListener("keyup", handle_change);
To solve this problem what you need to do is to put this in the event handler:
sel.value = sel.value;
This will set the internal value of the select kept by FF to the same value that is displayed in the select and which is also accessible on sel.value.

select value of dropdownlist item jquery

HTML
<select id="selectDepartment">
<option value="1">120</option>
<option value="2">20</option>
<option value="3">140</option>
<option value="4">4120</option>
<option value="5">560</option>
<option value="6">451</option>
<option value="7">310</option>
<option value="8">656</option>
<option value="9">444</option>
<option value="10">555</option>
<option value="11">2560</option>
<option value="12">450</option>
</select>
jQuery
$("#selectDepartment").change( function() {
alert($("select option:selected").val());
});
the above function always shows value 1 on alert, when I select any one of the options
Your method of finding the selection option is vague. You're saying "Grab all <select>s". You then go on to grab the :selected option from each of them (of all <select>s on the page). Continued, .val() takes the first value off the top.
Simply put, you're always fetching the selected value of the first <select> found on the page. Assuming #selectDepartment isn't the first <select>, your value will never change.
Try to keep the scope to within the current <Select> using this:
$('#selectDepartment').change(function(){
var selopt = $('option:selected',this);
});
Note that I specify the scope to within the <select> that triggered the .change(). Also note this really isn't necessary as val() works just as easily:
var selopt = $(this).val();
Let jQuery do the heavy lifting. You really only need option:selected if you want control over styling that specific element, or you're working with a multi-select and want more control.
You can do something like this:
$("#selectDepartment").change( function() {
var selected = $(this).find(":selected");
});

Is there an onSelect event or equivalent for HTML <select>?

I have an input form that lets me select from multiple options, and do something when the user changes the selection. Eg,
<select onChange="javascript:doSomething();">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Now, doSomething() only gets triggered when the selection changes.
I want to trigger doSomething() when the user selects any option, possibly the same one again.
I have tried using an "onClick" handler, but that gets triggered before the user starts the selection process.
So, is there a way to trigger a function on every select by the user?
Update:
The answer suggested by Darryl seemed to work, but it doesn't work consistently. Sometimes the event gets triggered as soon as user clicks the drop-down menu, even before the user has finished the selection process!
I needed something exactly the same. This is what worked for me:
<select onchange="doSomething();" onfocus="this.selectedIndex = -1;">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Supports this:
when the user selects any option, possibly the same one again
Here is the simplest way:
<select name="ab" onchange="if (this.selectedIndex) doSomething();">
<option value="-1">--</option>
<option value="1">option 1</option>
<option value="2">option 2</option>
<option value="3">option 3</option>
</select>
Works both with mouse selection and keyboard Up/Down keys whes select is focused.
I had the same problem when I was creating a design a few months back. The solution I found was to use .live("change", function()) in combination with .blur() on the element you are using.
If you wish to have it do something when the user simply clicks, instead of changing, just replace change with click.
I assigned my dropdown an ID, selected, and used the following:
$(function () {
$("#selected").live("change", function () {
// do whatever you need to do
// you want the element to lose focus immediately
// this is key to get this working.
$('#selected').blur();
});
});
I saw this one didn't have a selected answer, so I figured I'd give my input. This worked excellently for me, so hopefully someone else can use this code when they get stuck.
http://api.jquery.com/live/
Edit: Use the on selector as opposed to .live. See jQuery .on()
Just an idea, but is it possible to put an onclick on each of the <option> elements?
<select>
<option onclick="doSomething(this);">A</option>
<option onclick="doSomething(this);">B</option>
<option onclick="doSomething(this);">C</option>
</select>
Another option could be to use onblur on the select. This will fire anytime the user clicks away from the select. At this point you could determine what option was selected. To have this even trigger at the correct time, the onclick of the option's could blur the field (make something else active or just .blur() in jQuery).
If you really need this to work like this, I would do this (to ensure it works by keyboard and mouse)
Add an onfocus event handler to the select to set the "current" value
Add an onclick event handler to the select to handle mouse changes
Add an onkeypress event handler to the select to handle keyboard changes
Unfortunately the onclick will run multiple times (e.g. on onpening the select... and on selection/close) and the onkeypress may fire when nothing changes...
<script>
function setInitial(obj){
obj._initValue = obj.value;
}
function doSomething(obj){
//if you want to verify a change took place...
if(obj._initValue == obj.value){
//do nothing, no actual change occurred...
//or in your case if you want to make a minor update
doMinorUpdate();
} else {
//change happened
getNewData(obj.value);
}
}
</script>
<select onfocus="setInitial(this);" onclick="doSomething();" onkeypress="doSomething();">
...
</select>
The onclick approach is not entirely bad but as said, it will not be triggered when the value isn't changed by a mouse-click.
It is however possible to trigger the onclick event in the onchange event.
<select onchange="{doSomething(...);if(this.options[this.selectedIndex].onclick != null){this.options[this.selectedIndex].onclick(this);}}">
<option onclick="doSomethingElse(...);" value="A">A</option>
<option onclick="doSomethingElse(..);" value="B">B</option>
<option onclick="doSomethingElse(..);" value="Foo">C</option>
</select>
I know this question is very old now, but for anyone still running into this problem, I have achieved this with my own website by adding an onInput event to my option tag, then in that called function, retrieving the value of that option input.
<select id='dropdown' onInput='myFunction()'>
<option value='1'>1</option>
<option value='2'>2</option>
</select>
<p>Output: </p>
<span id='output'></span>
<script type='text/javascript'>
function myFunction() {
var optionValue = document.getElementById("dropdown").value;
document.getElementById("output").innerHTML = optionValue;
}
</script>
Going to expand on jitbit's answer. I found it weird when you clicked the drop down and then clicked off the drop down without selecting anything. Ended up with something along the lines of:
var lastSelectedOption = null;
DDChange = function(Dd) {
//Blur after change so that clicking again without
//losing focus re-triggers onfocus.
Dd.blur();
//The rest is whatever you want in the change.
var tcs = $("span.on_change_times");
tcs.html(+tcs.html() + 1);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
DDFocus = function(Dd) {
lastSelectedOption = Dd.prop("selectedIndex");
Dd.prop("selectedIndex", -1);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
//On blur, set it back to the value before they clicked
//away without selecting an option.
//
//This is what is typically weird for the user since they
//might click on the dropdown to look at other options,
//realize they didn't what to change anything, and
//click off the dropdown.
DDBlur = function(Dd) {
if (Dd.prop("selectedIndex") === -1)
Dd.prop("selectedIndex", lastSelectedOption);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="Dd" onchange="DDChange($(this));" onfocus="DDFocus($(this));" onblur="DDBlur($(this));">
<option>1</option>
<option>2</option>
</select>
<br/>
<br/>Selected index: <span class="selected_index"></span>
<br/>Times onchange triggered: <span class="on_change_times">0</span>
This makes a little more sense for the user and allows JavaScript to run every time they select any option including an earlier option.
The downside to this approach is that it breaks the ability to tab onto a drop down and use the arrow keys to select the value. This was acceptable for me since all the users click everything all the time until the end of eternity.
To properly fire an event every time the user selects something(even the same option), you just need to trick the select box.
Like others have said, specify a negative selectedIndex on focus to force the change event. While this does allow you to trick the select box, it won't work after that as long as it still has focus. The simple fix is to force the select box to blur, shown below.
Standard JS/HTML:
<select onchange="myCallback();" onfocus="this.selectedIndex=-1;this.blur();">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
jQuery Plugin:
<select>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
<script type="text/javascript">
$.fn.alwaysChange = function(callback) {
return this.each(function(){
var elem = this;
var $this = $(this);
$this.change(function(){
if(callback) callback($this.val());
}).focus(function(){
elem.selectedIndex = -1;
elem.blur();
});
});
}
$('select').alwaysChange(function(val){
// Optional change event callback,
// shorthand for $('select').alwaysChange().change(function(){});
});
</script>
You can see a working demo here.
first of all u use onChange as an event handler and then use flag variable to make it do the function u want every time u make a change
<select
var list = document.getElementById("list");
var flag = true ;
list.onchange = function () {
if(flag){
document.bgColor ="red";
flag = false;
}else{
document.bgColor ="green";
flag = true;
}
}
<select id="list">
<option>op1</option>
<option>op2</option>
<option>op3</option>
</select>
This may not directly answer your question, but this problem could be solved by simple design level adjustments. I understand this may not be 100% applicable to all use-cases, but I strongly urge you to consider re-thinking your user flow of your application and if the following design suggestion can be implemented.
I decided to do something simple than hacking alternatives for onChange() using other events that were not really meant for this purpose (blur, click, etc.)
The way I solved it:
Simply pre-pend a placeholder option tag such as select that has no value to it.
So, instead of just using the following structure, which requires hack-y alternatives:
<select>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Consider using this:
<select>
<option selected="selected">Select...</option>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
So, this way, your code is a LOT more simplified and the onChange will work as expected, every time the user decides to select something other than the default value. You could even add the disabled attribute to the first option if you don't want them to select it again and force them to select something from the options, thus triggering an onChange() fire.
At the time of this answer, I'm writing a complex Vue application and I found that this design choice has simplified my code a lot. I spent hours on this problem before I settled down with this solution and I didn't have to re-write a lot of my code. However, if I went with the hacky alternatives, I would have needed to account for the edge cases, to prevent double firing of ajax requests, etc. This also doesn't mess up the default browser behaviour as a nice bonus (tested on mobile browsers as well).
Sometimes, you just need to take a step back and think about the big picture for the simplest solution.
Add an extra option as the first, like the header of a column, which will be the default value of the dropdown button before click it and reset at the end of doSomething(), so when choose A/B/C, the onchange event always trigs, when the selection is State, do nothing and return. onclick is very unstable as many people mentioned before. So all we need to do is to make an initial button label which is different as your true options so the onchange will work on any option.
<select id="btnState" onchange="doSomething(this)">
<option value="State" selected="selected">State</option>
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
function doSomething(obj)
{
var btnValue = obj.options[obj.selectedIndex].value;
if (btnValue == "State")
{
//do nothing
return;
}
// Do your thing here
// reset
obj.selectedIndex = 0;
}
Actually, the onclick events will NOT fire when the user uses the keyboard to change the selection in the select control. You might have to use a combination of onChange and onClick to get the behavior you're looking for.
The wonderful thing about the select tag (in this scenario) is that it will grab its value from the option tags.
Try:
<select onChange="javascript:doSomething(this.value);">
<option value="A">A</option>
<option value="B">B</option>
<option value="Foo">C</option>
</select>
Worked decent for me.
2022 VANILLA JAVASCRIPT
...because this is a top hit on Google.
Original Poster did NOT ask for a JQuery solution, yet all answers ONLY demonstrate JQuery or inline SELECT tag event.
Use an event listener with the 'change' event.
const selectDropdown = document.querySelector('select');
selectDropdown.addEventListener('change', function (e) { /* your code */ });
... or call a seperate function:
function yourFunc(e) { /* your code here */ }
const selectDropdown = document.querySelector('select');
selectDropdown.addEventListener('change', yourFunc);
What I did when faced with a similar Problem is I added an 'onFocus' to the select box which appends a new generic option ('select an option'or something similar) and default it as the selected option.
So my goal was to be able to select the same value multiple times which essentially overwrites the the onchange() function and turn it into a useful onclick() method.
Based on the suggestions above I came up with this which works for me.
<select name="ab" id="hi" onchange="if (typeof(this.selectedIndex) != undefined) {alert($('#hi').val()); this.blur();}" onfocus="this.selectedIndex = -1;">
<option value="-1">--</option>
<option value="1">option 1</option>
<option value="2">option 2</option>
<option value="3">option 3</option>
</select>
http://jsfiddle.net/dR9tH/19/
Kindly note that Event Handlers are not supported for the OPTION tag on IE, with a quick thinking..I came up with this solution, try it and give me your feedback:
<script>
var flag = true;
function resetIndex(selObj) {
if(flag) selObj.selectedIndex = -1;
flag = true;
}
function doSomething(selObj) {
alert(selObj.value)
flag = false;
}
</script>
<select onchange="doSomething(this)" onclick="resetIndex(this)">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
What I'm doing here actually is resetting the select index so that the onchange event will be triggered always, true that you we lose the selected item when you click and it maybe annoying if your list is long, but it may help you in someway..
use jquery:
<select class="target">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
<script>
$('.target').change(function() { doSomething(); });
</script>
Here's my solution, completely different to any else on here. It uses the mouse position to figure out if an option was clicked as oppose to clicking on the select box to open the dropdown. It makes use of the event.screenY position as this is the only reliable cross browser variable. A hover event has to be attached first so it can figure out the controls position relative to the screen before the click event.
var select = $("select");
var screenDif = 0;
select.bind("hover", function (e) {
screenDif = e.screenY - e.clientY;
});
select.bind("click", function (e) {
var element = $(e.target);
var eventHorizon = screenDif + element.offset().top + element.height() - $(window).scrollTop();
if (e.screenY > eventHorizon)
alert("option clicked");
});
Here is my jsFiddle
http://jsfiddle.net/sU7EV/4/
you should try using option:selected
$("select option:selected").click(doSomething);
What works for me:
<select id='myID' onchange='doSomething();'>
<option value='0' selected> Select Option </option>
<option value='1' onclick='if (!document.getElementById("myID").onchange()) doSomething();' > A </option>
<option value='2' onclick='if (!document.getElementById("myID").onchange()) doSomething();' > B </option>
</select>
In that way, onchange calls 'doSomething()' when the option changes, and
onclick calls 'doSomething()' when onchange event is false, in other words, when you select the same option
Try this (event triggered exactly when you select option, without option changing):
$("select").mouseup(function() {
var open = $(this).data("isopen");
if(open) {
alert('selected');
}
$(this).data("isopen", !open);
});
http://jsbin.com/dowoloka/4
The one True answer is to not use the select field (if you need to do something when you re-select same answer.)
Create a dropdown menu with conventional div, button, show/hide menu. Link: https://www.w3schools.com/howto/howto_js_dropdown.asp
Could have been avoided had one been able to add event listeners to options. If there had been an onSelect listener for select element. And if clicking on the select field didn't aggravatingly fire off mousedown, mouseup, and click all at the same time on mousedown.
<script>
function abc(selectedguy) {
alert(selectedguy);
}
</script>
<select onchange="abc(this.selectedIndex);">
<option>option one</option>
<option>option two</option>
</select>
Here you have the index returned, and in the js code you can use this return with one switch or anything you want.
Try this:
<select id="nameSelect" onfocus="javascript:document.getElementById('nameSelect').selectedIndex=-1;" onchange="doSomething(this);">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
A long while ago now but in reply to the original question, would this help ?
Just put onClick into the SELECT line.
Then put what you want each OPTION to do in the OPTION lines.
ie:
<SELECT name="your name" onClick>
<option value ="Kilometres" onClick="YourFunction()">Kilometres
-------
-------
</SELECT>
<select name="test[]"
onchange="if(this.selectedIndex < 1){this.options[this.selectedIndex].selected = !1}">
<option>1</option>
<option>2</option>
<option>3</option>
</select>
I had faced a similar need and ended up writing a angularjs directive for the same -
guthub link - angular select
Used element[0].blur(); to remove the focus off the select tag. Logic is to trigger this blur on second click of the dropdown.
as-select gets triggered even when user selects the same value in the dropdown.
DEMO - link
There are a few things you want to do here to make sure it remembers older values and triggers an onchange event even if the same option is selected again.
The first thing you want is a regular onChange event:
$("#selectbox").on("change", function(){
console.log($(this).val());
doSomething();
});
To have the onChange event trigger even when the same option is selected again, you can unset selected option when the dropdown receives focus by setting it to an invalid value. But you also want to store the previously selected value to restore it in case the user does not select any new option:
prev_select_option = ""; //some kind of global var
$("#selectbox").on("focus", function(){
prev_select_option = $(this).val(); //store currently selected value
$(this).val("unknown"); //set to an invalid value
});
The above code will allow you to trigger onchange even if the same value is selected. However, if the user clicks outside the select box, you want to restore the previous value. We do it on onBlur:
$("#selectbox").on("blur", function(){
if ($(this).val() == null) {
//because we previously set an invalid value
//and user did not select any option
$(this).val(prev_select_option);
}
});

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