Javascript global variable vs. HTML data attribute - javascript

When we use $(this).data('options',$('#send1 option').clone());, it works, but when I use a global variable to store list data, it does not work. What is the difference between these two methods?
First method (works): This code clones data to the data attribute and then filters and copies to both send1 and send2.
$("#receiver").change(function() {
if ($(this).data('options') == undefined) {
/* Takes an array of all options-2 and kind of embeds it in select1 */
$(this).data('options',$('#send1 option').clone());
}
if ($(this).data('options-2') == undefined) {
$(this).data('options-2',$('#send2 option').clone());
}
var id1 = $(this).val();
console.log(id1);
var options1 = $(this).data('options').filter('[value=' + id1 + ']');
var options2 = $(this).data('options-2').filter('[value=' + id1 + ']');
$('.send1 ').html(options1);
$('.send2 ').html(options2);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<h5>Hello ListBox</h5>
<div>
<select name="Receiver" id="receiver">
<option value="1">Fruit</option>
<option value="2">Animal</option>
<option value="3">Bird</option>
<option value="4">Car</option>
</select>
<select class="send1" name="ShipFrom1" id="send1">
<option value="1">Banana</option>
<option value="1">Apple</option>
<option value="1">Orange</option>
<option value="2">Wolf</option>
<option value="2">Fox</option>
<option value="2">Bear</option>
<option value="3">Eagle</option>
<option value="3">Hawk</option>
<option value="4">BWM<option>
</select>
<select class="send2" name="ShipFrom2" id="send2">
<option value="1">Banana</option>
<option value="1">Apple</option>
<option value="1">Orange</option>
<option value="2">Wolf</option>
<option value="2">Fox</option>
<option value="2">Bear</option>
<option value="3">Eagle</option>
<option value="3">Hawk</option>
<option value="4">BWM<option>
</select>
</div>
Second method (doesn't work): This code uses a Javascript global variable. I am trying to clone the send1 options to a and then filter the global variable according to the value of receiver. Then, I copy the a result to both send1 and send2.
var a = $('#send1 option').clone();
$("#receiver").change(function() {
var id1 = $(this).val();
console.log(id1);
var options1 = a.filter('[value=' + id1 + ']');
$('.send1 ').html(options1);
$('.send2 ').html(options1);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<div>
<select name="Receiver" id="receiver">
<option value="1">Fruit</option>
<option value="2">Animal</option>
<option value="3">Bird</option>
<option value="4">Car</option>
</select>
<select class="send1" name="ShipFrom1" id="send1">
<option value="1">Banana</option>
<option value="1">Apple</option>
<option value="1">Orange</option>
<option value="2">Wolf</option>
<option value="2">Fox</option>
<option value="2">Bear</option>
<option value="3">Eagle</option>
<option value="3">Hawk</option>
<option value="4">BWM<option>
</select>
<select class="send2" name="ShipFrom2" id="send2">
<option value="1">Banana</option>
<option value="1">Apple</option>
<option value="1">Orange</option>
<option value="2">Wolf</option>
<option value="2">Fox</option>
<option value="2">Bear</option>
<option value="3">Eagle</option>
<option value="3">Hawk</option>
<option value="4">BWM<option>
</select>
</div>


I don't think you are using the best method for this ...
I suggest:
function setOption() {
var receiverVal = $('#receiver').val()
$('#send1 option:not(.'+receiverVal+')').hide();
$('#send2 option:not(.'+receiverVal+')').hide();
$('#send1 option.'+receiverVal).show();
$('#send2 option.'+receiverVal).show();
$('#send1 option:visible').first().attr('selected', 'selected');
$('#send2 option:visible').first().attr('selected', 'selected');
}
setOption();
$("#receiver").change(setOption)
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<select name="Receiver" id="receiver">
<option value="fruit" >Fruit</option>
<option value="animal">Animal</option>
<option value="bird" >Bird</option>
<option value="car" >Car</option>
</select>
<select class="send1" name="ShipFrom1" id="send1">
<option value="10" class="fruit" >Banana </option>
<option value="11" class="fruit" >Apple </option>
<option value="12" class="fruit" >Orange </option>
<option value="21" class="animal" >Wolf </option>
<option value="22" class="animal" >Fox </option>
<option value="23" class="animal" >Bear </option>
<option value="31" class="bird" >Eagle </option>
<option value="32" class="bird" >Hawk </option>
<option value="41" class="car" >BWM <option>
</select>
<select class="send2" name="ShipFrom2" id="send2" class="bird">
<option value="10" class="fruit" >Banana </option>
<option value="11" class="fruit" >Apple </option>
<option value="12" class="fruit" >Orange </option>
<option value="21" class="animal" >Wolf </option>
<option value="22" class="animal" >Fox </option>
<option value="23" class="animal" >Bear </option>
<option value="31" class="bird" >Eagle </option>
<option value="32" class="bird" >Hawk </option>
<option value="41" class="car" >BWM <option>
</select>

Related

Create array from all selected options of particular class

very new to this - I'm trying to make an array with all selected options from multiple drop downs. Have tried a little jQuery however only getting an array with the first selected option. When I try the below line in console it only returns selected 'Listening' score (HTML below):
var scoreArr = $.makeArray($('.curScore :selected'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="curLang">
<h3>Enter your four-skills language test scores:</h3>
<label for="Listening">Listening: <span class="required">*</span> </label>
<select class="curScore" id="Listening" name="Listening">
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>
<label for="Reading">Reading: <span class="required">*</span> </label>
<select class="curScore" id="Reading" name="Reading">
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>
Any help is appreciated!

Use jQuery's .map() to get the values and then use .get() to convert an array:
var $select = $('select');
var scoreArr = $select.map(function() {
return $(this).val();
})
.get();
console.log(scoreArr);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="curLang">
<h3>Enter your four-skills language test scores:</h3>
<label for="Listening">Listening: <span class="required">*</span> </label>
<select class="curScore" id="Listening" name="Listening">
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>
<label for="Reading">Reading: <span class="required">*</span> </label>
<select class="curScore" id="Reading" name="Reading">
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>

Check whether selected option has no value, across multiple select fields

When I try the below jQuery, I get an error:
Unexpected Type Error (: $selReqs[i].val is not a function)
I have tried multiple variations of the below and cannot seem to get it to check if selected option has no value for each of the select fields. Any advice appreciated!
var $selReqs = $('.allMinReqs');
var reqs = [];
for(var i=0; i < $selReqs.length; i++) {
if(!$selReqs[i].val()) {
reqs.push($selReqs[i]);
}
}
<div id="minReqs">
<div class="hide" id="singleMin_mcReq"><br>
<label for="singleMin">Minimum requirement for each skill: <span class="required">*</span> </label>
<select class="allMinReqs" id="singleMin" onchange="showMcStart();">
<option value="">Please Select</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
</select>
</div>
<div class="hide" id="multiMin_mcReq"><br>
<label for="curL">Listening requirement: <span class="required">*</span> </label>
<select class="allMinReqs" id="mcReq_L">
<option value="">Please Select</option>
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>
<label for="curR">Reading requirement: <span class="required">*</span> </label>
<select class="allMinReqs" id="mcReq_R">
<option value="">Please Select</option>
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>

The issue in your code is because you're accessing a jQuery object by index. This returns the underlying DOM Element object which has no val() method.
To achieve your goal you could use map() to create an array of all the selected values. Then you can check the length of that array to determine if anything was selected, like this:
$('button').on('click', function() {
var values = $('.allMinReqs').map((i, e) => e.value !== '' ? e.value : null).get();
console.log(values);
var somethingSelected = values.length != 0;
console.log(somethingSelected);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button>Check</button>
<div id="minReqs">
<div class="hide" id="singleMin_mcReq"><br>
<label for="singleMin">Minimum requirement for each skill: <span class="required">*</span> </label>
<select class="allMinReqs" id="singleMin">
<option value="">Please Select</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
</select>
</div>
<div class="hide" id="multiMin_mcReq"><br>
<label for="curL">Listening requirement: <span class="required">*</span> </label>
<select class="allMinReqs" id="mcReq_L">
<option value="">Please Select</option>
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>
<label for="curR">Reading requirement: <span class="required">*</span> </label>
<select class="allMinReqs" id="mcReq_R">
<option value="">Please Select</option>
<option value="4">4.0</option>
<option value="4.5">4.5</option>
<option value="5">5.0</option>
<option value="5.5">5.5</option>
<option value="6">6.0</option>
<option value="6.5">6.5</option>
<option value="7">7.0</option>
<option value="7.5">7.5</option>
<option value="8">8.0</option>
<option value="8.5">8.5</option>
<option value="9">9.0</option>
<option value="9.5">9.5</option>
</select>

How to make an if statement to disable select option?

I have three select menus where the user selects a subject, year and season. However, I want it so that if the user selects the year '2019', the 'Fall' option will get disabled.
<select name="Subject">
<option value="Math">Math</option>
<option value="Physics">Physics</option>
<option value="Chemistry">Chemistry</option>
<option value="Biology">Biology</option>
</select>
<select name="Year">
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
</select>
<select name="Season">
<option value="Spring">Spring</option>
<option value="Fall">Fall</option>
</select>

Create and event handler for the Year's change event and disable the season based on what Year's new value is.
https://jsfiddle.net/075fnm4a/
HTML
<select name="Subject">
<option value="Math">Math</option>
<option value="Physics">Physics</option>
<option value="Chemistry">Chemistry</option>
<option value="Biology">Biology</option>
</select>
<select name="Year">
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
</select>
<select name="Season">
<option value="Spring">Spring</option>
<option value="Fall">Fall</option>
</select>
Jquery
$(document).ready(function(){
$('select[name="Year"]').on('change',function(){
var $this = $(this);
$('select[name="Season"]').find('option[value="Fall"]').prop('disabled', ($this.val() == '2019') ); // disabled or enabled
});
$('select[name="Year"]').trigger('change');
});

Like this.
document.querySelector('#year').onchange = ev => {
const value = ev.target.value;
if (value === '2019') {
document.querySelector('#fall').disabled = true;
} else {
document.querySelector('#fall').disabled = false;
}
}
<select name="Subject">
<option value="Math">Math</option>
<option value="Physics">Physics</option>
<option value="Chemistry">Chemistry</option>
<option value="Biology">Biology</option>
</select>
<select name="Year" id="year">
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
</select>
<select name="Season">
<option value="Spring">Spring</option>
<option value="Fall" id="fall" disabled>Fall</option>
</select>

<select name="Subject">
<option value="Math">Math</option>
<option value="Physics">Physics</option>
<option value="Chemistry">Chemistry</option>
<option value="Biology">Biology</option>
</select>
<select name="Year" id="years">
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
</select>
<select name="Season" id="seasons">
<option value="Spring">Spring</option>
<option value="Fall">Fall</option>
</select>
$('#years').on('change', function(){
if($(this).val()==='2019'){
$("#seasons option").each(function()
{
if($(this).val() === 'Fall'){
$(this).attr('disabled', 'disabled');
}
});
}
});

You can onchange event and bind callback to it that get season select element and enable and disable Fall season according to selection value
<select name="Subject">
<option value="Math">Math</option>
<option value="Physics">Physics</option>
<option value="Chemistry">Chemistry</option>
<option value="Biology">Biology</option>
</select>
<select name="Year" onchange="changeYear(this.value)">
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
</select>
<select name="Season">
<option value="Spring" >Spring</option>
<option value="Fall" disabled>Fall</option>
</select>
<script>
function changeYear(value)
{
var seasons = document.getElementsByName("Season")[0].options;
var fallSeason = Array.apply(null, seasons).find(season => season.value === 'Fall');
fallSeason.disabled = (value==='2019')
}
</script>

How to set condition in dropdown list in HTML?

Here is my code for drop-down list part.
What should I add in to make the option selected when the value is matched with the option value? How to set condition like 'if value=50 ,selected = selected' ?
<label>Quantity:</label><br><br>
<select name="qty" id="qty" value="{{ qty }}">
<option value="50">50</option>
<option value="100">100</option>
<option value="150">150</option>
<option value="200">200</option>
<option value="250">250</option>
<option value="300">300</option>
<option value="350">350</option>
<option value="400">400</option>
<option value="450">450</option>
<option value="500">500</option>
</select>

following code make the option selected when the value is matched with the option value.
<label>Quantity:</label><br><br>
<select name="qty" id="qty">
<option value="50">50</option>
<option value="100">100</option>
<option value="150">150</option>
<option value="200">200</option>
<option value="250">250</option>
<option value="300">300</option>
<option value="350">350</option>
<option value="400">400</option>
<option value="450">450</option>
<option value="500">500</option>
</select>
<script>
$(document).ready(function(){
$('#qty option[value={{ $qty }}]').attr('selected','selected');
});
</script>

Replace value from select inside hidden input

The main mission was to add the values from two select dropdowns to one hidden input. That works great but now if a user decides to choose another input, it adds to the hidden input value rather than replace it.
Live Code: DEMO
$('#expireMM').change(function() {
var theMonth = $(this).val();
$("#expiry").val( theMonth )
})
$('#expireYY').change(function() {
var theYear = $(this).val();
$('#expiry').val($('#expiry').val() + "/" + theYear );
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="expireMM" id="expireMM" >
<option value="">Month</option>
<option value="01">January</option>
<option value="02">February</option>
<option value="03">March</option>
<option value="04">April</option>
<option value="05">May</option>
<option value="06">June</option>
<option value="07">July</option>
<option value="08">August</option>
<option value="09">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="expireYY" id="expireYY" >
<option value="">Year</option>
<option value="17">2017</option>
<option value="18">2018</option>
<option value="19">2019</option>
<option value="20">2020</option>
<option value="21">2021</option>
</select>
<input class="inputCard" type="hidden" name="expiry" id="expiry" maxlength="4" />

You can update the value of the #expiry input in an external function, and not based on the current value:
function getExpirationDate() {
var monthVal = $('#expireMM').val();
var yearVal = $('#expireYY').val();
if (monthVal && yearVal) {
$('#expiry').val(`${monthVal}/${yearVal}`);
} else if (monthVal) {
$('#expiry').val(monthVal);
}
console.log($('#expiry').val());
}
$('#expireMM').change(getExpirationDate)
$('#expireYY').change(getExpirationDate)
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="expireMM" id="expireMM" >
<option value="">Month</option>
<option value="01">January</option>
<option value="02">February</option>
<option value="03">March</option>
<option value="04">April</option>
<option value="05">May</option>
<option value="06">June</option>
<option value="07">July</option>
<option value="08">August</option>
<option value="09">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="expireYY" id="expireYY" >
<option value="">Year</option>
<option value="17">2017</option>
<option value="18">2018</option>
<option value="19">2019</option>
<option value="20">2020</option>
<option value="21">2021</option>
</select>
<input class="inputCard" type="hidden" name="expiry" id="expiry" maxlength="4" />

$("#expiry").val($("#expireMM").val() + "/" + $("#expireYY").val())

Why not generate you expiry input value on form submit?
Here is the code.
jQuery(document).ready(function($) {
$("#my-form").submit(function() {
var monthYearVal = $('#expireMM').val() + "/" + $('#expireYY').val();
$("#expiry").val(monthYearVal);
$(this).submit();
return false;
});
});
<form id="my-form" method="POST">
<table class="table">
<tr>
<td>
<select name="expireMM" id="expireMM">
<option value="">Month</option>
<option value="01">January</option>
<option value="02">February</option>
<option value="03">March</option>
<option value="04">April</option>
<option value="05">May</option>
<option value="06">June</option>
<option value="07">July</option>
<option value="08">August</option>
<option value="09">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="expireYY" id="expireYY">
<option value="">Year</option>
<option value="17">2017</option>
<option value="18">2018</option>
<option value="19">2019</option>
<option value="20">2020</option>
<option value="21">2021</option>
</select>
<input class="inputCard" type="hidden" name="expiry" id="expiry" maxlength="4" /></tr>
</td>
<tr>
<tr>
<td colspan="2" align=center>
<input type="hidden" name="cvv">
<input class="right-col-inner-box" type="submit" value="Submit">
</td>
</tr>
</table>
</form>

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