Display items of two drop down based on each other - javascript

I have two drop downs with exactly the same values.
I want the drop down 2 to display the values based on the selection of items of drop down 1.
So the selected index of drop down 2 will be equal to or more than the selected index of drop down 1.
document.getElementById("SELECTB").selectedIndex >= document.getElementById("SELECTA").selectedIndex
So if B is selected in Drop down 1 then selectable options in drop down 2 will be B,C and D. (A will be not selectable item)
http://jsfiddle.net/xxyhm78t/1/

Solution working with pure Javascript:
var select1 = document.getElementById("SELECTA");
var select2 = document.getElementById("SELECTB");
select1.onchange = function () {
while (select2.firstChild) {
select2.removeChild(select2.firstChild);
}
for (var i = select1.selectedIndex; i < select1.options.length; i++) {
var o = document.createElement("option");
o.value = select1.options[i].value;
o.text = select1.options[i].text;
select2.appendChild(o);
}
}
Fiddle
Reference: This is an adjusted solution from javascript Change the Dropdown values based on other dropdown
Update: Like asked in the comment - to disable the options instead of removing them:
var select1 = document.getElementById("SELECTA");
var select2 = document.getElementById("SELECTB");
select1.onchange = function () {
while (select2.firstChild) {
select2.removeChild(select2.firstChild);
}
for (var i = 0; i < select1.options.length; i++) {
var o = document.createElement("option");
o.value = select1.options[i].value;
o.text = select1.options[i].text;
(i <= select1.selectedIndex)
? o.disabled = true
: o.disabled = false ;
select2.appendChild(o);
}
}
Adjusted Fiddle
Update 2: Like asked in the comment if it's possible to adjust this to use class names instead of ids - yes, by using getElementsByClassName(). I've adjusted in this Fiddle both selects to have class="SELECTA" and class="SELECTB" instead of the previously used id. The according adjustment for the Javascript is only the declaration of the variables:
var select1 = document.getElementsByClassName("SELECTA")[0];
var select2 = document.getElementsByClassName("SELECTB")[0];
As you already know, an id is a unique attribute, therefore it's possible to get a single element using getElementById(). getElementsByClassName() returns a collection of HTML elements instead, even if there's only a single element having the class. So it's - in this example - necessary to address the 1st element of this collection. As counting starts by 0, the first (and only) element having the class "SELECTA" is getElementsByClassName("SELECTA")[0].
Reference: https://developer.mozilla.org/en-US/docs/Web/API/document.getElementsByClassName#Syntax

You can do this using selectedIndex with the following piece of code:
$("#SELECTA").change(function() {
var selIndex = this.selectedIndex;
$("#SELECTB").find("option").each(function(k,v) {
$(this).attr("disabled", selIndex > k);
});
});
Depending on what it is you are after, you may need to reset #SELECTB if one of the disabled values is selected.

I think this is what you are looking for:
$("select").on("change", function (e) {
var sel = this.selectedIndex;
$("#SELECTB option").each(function (i, e) {
$(this).prop("disabled", sel > i);
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="SELECTA">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
<option value="D">D</option>
</select>
<select id="SELECTB">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
<option value="D">D</option>
</select>
And this can be even more general:
$("select").on("change", function (e) {
var sel = this.selectedIndex;
var nextSelect = $(this).parent().find("select").not(this);
$(nextSelect).children().each(function (i, e) {
$(this).prop("disabled", sel > i);
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="SELECTA">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
<option value="D">D</option>
</select>
<select id="SELECTB">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
<option value="D">D</option>
</select>

Related

Multiple values of <option>

I would like to put multiple values in tag within select, so I could adress precisely one or few items.
Example:
<select id="select1">
<option value="pf, nn">NN</option>
<option value="pf, x2, jj">JJ</option>
<option value="pf, uu">UU</option>
<option value="pf, x2, oo">OO</option>
<option value="tt">TT</option>
<option value="rr">RR</option>
</select>
In my js I got that one function that depend on one value that is common for many items:
if (document.getElementById("select1").value = "pf";) {
// do something;
}
if (document.getElementById("select1").value = "x2";) {
// do some-other-thing;
}
But I don't want to use (cos' and with more options gonna get messy)
var sel1 = document.getElementById("select1").value
if (sel1="nn" || sel1="jj" || sel1="uu" || sel1="oo") {
// do something;
}
if (sel1="jj" || sel1="oo") {
// do some-other-thing;
}
Neverthelesst I need to be able to set item by precise one value
if (document.somethingelse = true) {
document.getElementById("select1").value = "oo";)
}
Is there a nice way to achieve this? Maybe use some other "value-like" attribute of option (but which?)?
Only JS.
I think you can do what you want with selectedOpt.value.split(",").includes("sth") code:
$(document).ready(function(e){
selectedChange($("#select1")[0])
});
function selectedChange(val) {
var selectedOpt = val.options[val.selectedIndex];
var status1 = selectedOpt.value.split(",").includes("x2");
var status2 = selectedOpt.value.split(",").includes("pf");
console.log(status1);
console.log(status2);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="select1" onchange="selectedChange(this)">
<option value="pf,nn">NN</option>
<option value="pf,x2,jj">JJ</option>
<option value="pf,uu">UU</option>
<option value="pf,x2,oo">OO</option>
<option value="tt">TT</option>
<option value="rr">RR</option>
</select>

Using jQuery to check and see if a select box has/or contains selected options

Using jQuery, upon a change/select event, how can I check and see if multiple select boxes contain any selected items? All I am looking for is how to capture and obtain a total count of this?
Based on a validation if not equal to 0, this would set a buttons default disabled attribute to false.
<form id="myform">
Cars
<select id="car">
<option value=""></option>
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<br><br>
Fruits
<select id="fruits">
<option value=""></option>
<option value="apple">apple</option>
<option value="banana">banana</option>
<option value="pear">pear</option>
<option value="strawberry">strawberry</option>
<option value="mango">mango</option>
<option value="orange">orange</option>
</select>
</form>
$('#myform select).bind("change select",function() {
});
Assuming your <button> is within the form element, the following should work for you:
// binding the anonymous function of the on() method
// as the event-handler for the 'change' event:
$('#myform').on('change', function() {
// caching the $(this) (the <form>, in this case):
var form = $(this);
// finding the <button> element(s) within the <form>
// (note that a more specific selector would be
// preferable), and updating the 'disabled' property,
// finding all <option> elements that are selected,
// filtering that collection:
form.find('button').prop('disabled', form.find('select option:selected').filter(function() {
// retaining only those whose values have a length
// (in order to not-count the default 'empty'
// <option> elements:
return this.value.length;
// and then checking if that collection is
// equal to 0, to obtain a Boolean true
// disabling the <button>, or a false to
// enable the <button>:
}).length === 0);
// triggering the change event on page-load
// to appropriately enable/disable the <button>:
}).change();
$('#myform').on('change', function() {
var form = $(this);
form.find('button').prop('disabled', form.find('select option:selected').filter(function() {
return this.value.length;
}).length === 0);
}).change();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="myform">
Cars
<select id="car">
<option value=""></option>
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<br>
<br>Fruits
<select id="fruits">
<option value=""></option>
<option value="apple">apple</option>
<option value="banana">banana</option>
<option value="pear">pear</option>
<option value="strawberry">strawberry</option>
<option value="mango">mango</option>
<option value="orange">orange</option>
</select>
<button>Submission button</button>
</form>
References:
change().
filter().
find().
on().
prop().
You can use the jQuery :checked selector to capture all elements that are checked. For the count, you can do:
$( "input:checked" ).length;
You can then do your condition to view if there are zero or more elements checked:
var selected = $( "input:checked" ).length;
if(selected > 0)
//do something
$('#myform select').on('change', function() {
var count = 0;
$('#myform').find('select').find('option').each(function(){
if ($(this).is(':selected')){
count++;
}
});
if (count < 0){
$('#mybutton').prop('disabled', false);
} else {
$('#mybutton').prop('disabled', true);
});
Grab all the selects on the page and just loop through them while adding a change event to each one.
Then in that change event, call a method that counts up how many selects have items selected.
https://jsfiddle.net/x833qr20/3/
// put an on change event on all the selects, can be done in onload
var ddl = $('select');
for (i = 0; i < ddl.length; i++) {
ddl[i].onchange = function() {
CountAllSelectedDDL();
}
}
// function that fires when one select gets changed
function CountAllSelectedDDL() {
var ddl = $('select');
var count = 0;
for (i = 0; i < ddl.length; i++) {
if (ddl[i].selectedIndex > 0) {
count++;
}
}
var button = document.getElementById('button');
if (count > 0) {
// set the buttons default disabled attribute to false
button.disabled = false;
} else {
button.disabled = true;
}
}
Hope this helps.
Here's a working example via jQuery
https://jsfiddle.net/wedh87bm/
$('#myform select').bind("change select",function() {
var completed = true;
$('#myform select').each(function(){
if($(this).val() == "")
{
completed = false;
}
});
if(completed)
{
$('#validate').prop("disabled",false);
} else
{
$('#validate').prop("disabled",true);
}
});

Remove the duplicate values and combinations in html select option

I have a dynamically generated <select> field with <option>.
<select>
<option value=""></option>
<option value=""></option>
<option value=""> False</option>
<option value=""> True</option>
<option value="">False False</option>
<option value="">False True</option>
<option value="">True</option>
<option value="">True True</option>
</select>
I would like to remove the duplicate occurrences and combinations. The final <select> field with <option> should look like :
<select>
<option value=""></option>
<option value="">False</option>
<option value="">True</option>
</select>
Here is how my fiddle looks like. Been trying to solve this for hours.
var values = [];
$("select").children().each(function() {
if (values.length > 0) {
var notExists = false;
for (var x = 0; x < values.length; x++) {
var _text = this.text.replace(/\s/g, "");
var value = values[x].replace(/\s/g, "");
if (values[x].length > _text.length) {
//console.log('>>+', value, ' || ', _text, value.indexOf(_text))
notExists = value.indexOf(_text) > -1 ? true : false;
} else {
//console.log('>>*', value, ' || ', _text, _text.indexOf(value))
notExists = _text.indexOf(value) > -1 ? true : false;
}
}
if (notExists) {
//this.remove();
values.push(this.text);
}
} else {
values.push(this.text);
}
});
Any help to solve this is appreciated.
You can use map() to return all options text and use split() on white-space. Then to remove duplicates you can use reduce() to return object. Then you can empty select and use Object.keys() to loop each property and append to select.
var opt = $("select option").map(function() {
return $(this).text().split(' ')
}).get();
opt = opt.reduce(function(o, e) {return o[e] = true, o}, {});
$('select').empty();
Object.keys(opt).forEach(function(key) {
$('select').append(' <option value="">'+key+'</option>');
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select>
<option value=""></option>
<option value=""></option>
<option value="">False</option>
<option value="">True</option>
<option value="">False False</option>
<option value="">False True</option>
<option value="">True</option>
<option value="">True True</option>
</select>
You can loop through each of this children text , then use substring to get the first text & put it in an array.
Once done empty the select element and append the newly created options
var _textHolder=[]; // NA empty array to hold unique text
var _options="";
$("select").children().each(function(item,value) {
var _textVal = $(this).text().trim(); // Remove white space
//get the first text content
var _getText = _textVal.substr(0, _textVal.indexOf(" "));
// if this text is not present in array then push it
if(_textHolder.indexOf(_getText) ==-1){
_textHolder.push(_getText)
}
});
// Create new options with items from _textHolder
_textHolder.forEach(function(item){
_options+='<option value="">'+item+'</option>'
})
// Empty current select element and append new options
$('select').empty().append(_options);
JSFIDDLE
I would do with pure JS ES6 style. This is producing a words array from the whitespace separated options element's innerText value regardless the words are in the front, middle or the end; and it will create a unique options list from that. Basically we are concatenating these arrays and getting it unified by utilizing the new Set object. The code is as follows;
var opts = document.querySelector("select").children,
list = Array.prototype.reduce.call(opts, function(s,c){
text = c.innerText.trim().split(" ");
return new Set([...s].concat(text)) // adding multiple elements to a set
},new Set());
list = [...list]; // turn set to array
for (var i = opts.length-1; i >= 0; i--){ //reverse iteration not to effect indices when an element is deleted
i in list ? opts[i].innerText = list[i]
: opts[i].parentNode.removeChild(opts[i]);
}
<select>
<option value=""></option>
<option value=""></option>
<option value=""> False</option>
<option value=""> True</option>
<option value="">False False</option>
<option value="">False True</option>
<option value="">True</option>
<option value="">True True</option>
</select>

How to add a "random" button that applies to two drop down menus

I have created a page with two drop-down menus containing various values.
Now I would like to add a "randomize" button. When clicked, this button would select any of the values at random in both fields. (the values are also copied on a box above each menu).
Project idea for drop down menus
So far I've coded the menus and the words display in the boxes above them when the user selects them. But now I'm trying to add a randomise button that would put any of the values in the drop down as selected and of course displayed in the above text box. Ideally, more values in the drop-down menus would be added every once in a while without making the script dysfunctional... and ideally it would all be contained in a HTML file (calling for JQuery or javascript is ok).
I've looked at this but it doesn't apply.
I also looked at this but it's not really a feature that the user activates.
Very grateful if anyone can help! Thanks
hope this helps
HTML :
<select id="s1">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<select id="s2">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
Javascript:
var minNumber = 0;
var maxNumber = 3;
function randomNumberFromRange(min,max)
{
return Math.floor(Math.random()*(max-min+1)+min);
}
$("#s2")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);
$("#s1")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);
I create this fiddle for you...
https://jsfiddle.net/s59g8vdp/
The first example you have provided is very close to what you want to do. You just need to:
Get a random value between 0 and options.length - 1.
Get option[random] and set its selected property to true.
Copy that option's .innerHTML or .value to the .innerHTML or .value of the label on top of the dropdowns.
This is all you probably need:
function randomizeSelect(selectId, fieldId) {
var options = document.getElementById(selectId).children;
var random = Math.floor(options.length * (Math.random() % 1));
var option = options[random];
option.selected = true;
document.getElementById(fieldId).value = option.innerHTML; // You can use .value instead in both places
}
var values = {};
window.onload = function(e) {
document.onchange = function(e) { // Event Delegation: http://davidwalsh.name/event-delegate
var t = e.target;
if(t.tagName == "SELECT")
document.getElementById(t.id.replace("Select","Label")).value = t.children[t.selectedIndex].innerHTML;
}
document.oninput = function(e) {
var t = e.target;
if(t.tagName == "INPUT") {
if(values.hasOwnProperty(t.id))
var options = values[t.id];
else
var options = document.getElementById(t.id.replace("Label","Select")).children;
var currentValue = t.value;
for(i in options) {
if(options[i].innerHTML == currentValue) { // Can also use .value
options[i].selected = true;
break;
}
}
}
}
document.getElementById("randomize").onclick = function(e) {
randomizeSelect("leftSelect", "leftLabel");
randomizeSelect("rightSelect", "rightLabel");
}
}
<input type="text" id="leftLabel" value="Left 1">
<select id="leftSelect">
<option value="l1" selected>Left 1</option>
<option value="l2">Left 2</option>
<option value="l3">Left 3</option>
</select>
<input type="text" id="rightLabel" value="Right 1">
<select id="rightSelect">
<option value="r1" selected>Right 1</option>
<option value="r2">Right 2</option>
<option value="r3">Right 3</option>
</select>
<button id="randomize">RANDOMIZE</button>
This will create random number and click on random div menu:
$(function(){
$(".menu").click(function(){
alert("you clicked "+$(this).text());
});
});
function doSomthing(){
var rand=Math.floor((Math.random() * 5));
alert(rand+1);
var ele = $(".menu").get(rand);
$(ele).click();
}
fiddle example: link
Or you can use this example to put value in the menu, or wherever you want: link 2
just a concept how to make that
$('input').on('click',function(){
var randomnum = Math.floor(Math.random()*$('ul li').length);
alert($('ul li').eq(randomnum).text());
});
DEMO FIDDLE
Randomize Button added
see... ;) i hope this solve your problem!
https://jsfiddle.net/s59g8vdp/1/
Html :
<select id="s1">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<select id="s2">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<a id="randomize" href="#">randomize</a>
Javascript :
var minNumber = 0;
var maxNumber = 3;
$("#randomize").click(function(){
$("#s2")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);
$("#s1")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);
});
function randomNumberFromRange(min,max)
{
return Math.floor(Math.random()*(max-min+1)+min);
}
$("#s2")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);
$("#s1")[0].selectedIndex = randomNumberFromRange(minNumber, maxNumber);

How can I remove options with the same text from a select element?

I have a select element that shows multiple options with the same text:
<select name="tur" id="tur">
<option value="1">a</option>
<option value="2">a</option>
<option value="3">a</option>
<option value="4">a</option>
<option value="5">b</option>
<option value="6">b</option>
<option value="7">c</option>
<option value="8">d</option>
</select>
Using JavaScript, I would like to remove these duplicates so that only one of each is shown:
<select name="tur" id="tur">
<option value="1">a</option>
<option value="5">b</option>
<option value="7">c</option>
<option value="8">d</option>
You can loop through the <option> elements, checking each one to see if its text content is in an array. If it is, remove the <option>. If not, add its content to the array. This will remove options that are redundant in the list.
Try it out: http://jsfiddle.net/FXq8W/
​var array = [];
​$('#tur option').each(function() {
var $th = $(this);
var text = $th.text();
if( $.inArray(text, array) > -1 ) {
$th.remove();
} else {
array.push( text );
}
});​​​​​​​​​​​​​​
http://api.jquery.com/jquery.inarray/
var remove = [], values = {}, value, i;
var options = document.getElementById('tur').getElementsByTagName('option');
for (i=0; i<options.length; i++) {
value = options[i].innerHTML.replace(/^\s*|\s*$/g, '');
if (value in values) remove.push(options[i]);
else values[value] = true;
}
for (i=0; i<remove.length; i++) {
remove[i].parentNode.removeChild(remove[i]);
}

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