选择选项1时禁用选项2

Question

I need to adapt some code I've used for a website I'm creating for a school I work for, to disallow certain options to be selected at the same time.

The user is presented the following HTML drop down list 6 times:

<select type="select" name="optRes2" select id="optRes2">
    <option value="" disabled selected hidden>Please select an option...</option>
    <option value="Art">Art</option>
    <option value="Business Studies">Business Studies</option>
    <option value="Computing">Computing</option>
    <option value="Drama">Drama</option>
    <option value="French">French</option>
    <option value="Food Technology">Food Technology</option>
    <option value="Geography">Geography</option>
    <option value="German">German</option>
    <option value="History">History</option>
    <option value="Music">Music</option>
    <option value="Philosophy and Ethics">Philosophy and Ethics</option>
    <option value="Product Design">Product Design</option>
    <option value="Physical Education">Physical Education</option>
    <option value="Spanish">Spanish</option>
    <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option>
    <option value="Textiles">Textiles</option>
</select>

The user should NOT be able to select both Art and Textiles at the same time. They can select EITHER Art OR Textiles - but not both.

For example: User selects 'Art' in opt1, so Textiles is disabled in the remaining 5 menus. If the user goes back and deselects Art, Textiles should then be enabled throughout. Hopefully you understand what I mean.

I already have the code to prevent the same option being selected multiple times:

$(function() {
    $('select').change(function(){
        if($(this).attr('id') == 'opt1' && $(this).val() == 'Default'){
            $('select').not(this).prop('disabled', true).val('Disabled');
        } else {
            $('select').not(this).removeProp('disabled');
            $('select option').removeProp('disabled');
            $('select').each(function() {
                var val = $(this).val();
                if(val != 'Default' || val != 'Disabled'){
                    $('select option[value="'+val+'"]').not(this).prop('disabled', true);
                }
            });
        }
    });
});

The user then clicks submit and all of this is then submit to a MySQL server for review at a later date.

Menus are named opt1, opt2, opt3, opt4, optRes1 and optRes2.

Thanks everyone,

Jack

Answer 1

Try to add a overlapping div with id selection and then select every select and disable the chosen option on change like so:

<div id="selection">
            <select type="select" name="optRes2" select id="optRes2">
                <option value="" disabled selected hidden>Please select an option...                       </option>
                <option value="Art">Art</option>
                 etc
            </select>
    <select type="select" name="optRes3" select id="optRes3">
                <option value="" disabled selected hidden>Please select an option...                       </option>
                <option value="Art">Art</option>
                 etc
            </select>
    </div>

and the script

<script type="text/JavaScript" language="JavaScript">
    $( "#optRes2" ).change(function() {
      $("div#selection select.select option").each(function(){
             if($(this).val()== $('#optRes2').val() ){ 
                $(this).attr("disabled","true");    
             }
       });
    });
    $( "#optRes3" ).change(function() {
      $("div#selection select.select option").each(function(){
             if($(this).val()== $('#optRes3').val() ){ 
                $(this).attr("disabled","true");    
             }
       });
    });
</script>

Answer 2

I use a data attribute named notallowed . There you can set which value that should be disabled. And when a value is changed we also check if we previously disabled some fields and re-enable them.

 $('select').change(function(){ var notAllowed = $(this).find('option:selected').data('notallowed'); var currentValue = $(this).val(); // Get the previous selected value. var oldValue = $(this).data('old'); // Keep track of the previous selected value. $(this).data('old', currentValue); // Re-enabled all that was disabled by the previous selection. if(oldValue) { // Re-enable the old value in the other selects. $('select').not(this).find('option[value="' + oldValue +'"]').prop('disabled', false); // Get the option. var previousNotAllowed = $(this).find('option[value="' + oldValue +'"]').data('notallowed'); if(previousNotAllowed){ $('select').not(this).find('option[value="' + previousNotAllowed +'"]').prop('disabled', false); } } // If we selected a option with notallowed attribute we should disable that option in the other selects. if(notAllowed){ var items = $('select').not(this).find('option[value="' + notAllowed +'"]').prop('disabled',true); } // Disable the current value in other selects. $('select').not(this).find('option[value="' + currentValue +'"]').prop('disabled', true); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <select type="select" name="optRes1" select id="optRes1"> <option value="" disabled selected hidden>Please select an option...</option> <option value="Art" data-notallowed="Textiles">Art</option> <option value="Business Studies">Business Studies</option> <option value="Computing" data-notallowed="Drama">Computing</option> <option value="Drama" data-notallowed="Computing">Drama</option> <option value="French">French</option> <option value="Food Technology">Food Technology</option> <option value="Geography">Geography</option> <option value="German">German</option> <option value="History">History</option> <option value="Music">Music</option> <option value="Philosophy and Ethics">Philosophy and Ethics</option> <option value="Product Design">Product Design</option> <option value="Physical Education">Physical Education</option> <option value="Spanish">Spanish</option> <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option> <option value="Textiles" data-notallowed="Art">Textiles</option> </select> <select type="select" name="optRes2" select id="optRes2"> <option value="" disabled selected hidden>Please select an option...</option> <option value="Art" data-notallowed="Textiles">Art</option> <option value="Business Studies">Business Studies</option> <option value="Computing" data-notallowed="Drama">Computing</option> <option value="Drama" data-notallowed="Computing">Drama</option> <option value="French">French</option> <option value="Food Technology">Food Technology</option> <option value="Geography">Geography</option> <option value="German">German</option> <option value="History">History</option> <option value="Music">Music</option> <option value="Philosophy and Ethics">Philosophy and Ethics</option> <option value="Product Design">Product Design</option> <option value="Physical Education">Physical Education</option> <option value="Spanish">Spanish</option> <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option> <option value="Textiles" data-notallowed="Art">Textiles</option> </select> <select type="select" name="optRes3" select id="optRes3"> <option value="" disabled selected hidden>Please select an option...</option> <option value="Art" data-notallowed="Textiles">Art</option> <option value="Business Studies">Business Studies</option> <option value="Computing" data-notallowed="Drama">Computing</option> <option value="Drama" data-notallowed="Computing">Drama</option> <option value="French">French</option> <option value="Food Technology">Food Technology</option> <option value="Geography">Geography</option> <option value="German">German</option> <option value="History">History</option> <option value="Music">Music</option> <option value="Philosophy and Ethics">Philosophy and Ethics</option> <option value="Product Design">Product Design</option> <option value="Physical Education">Physical Education</option> <option value="Spanish">Spanish</option> <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option> <option value="Textiles" data-notallowed="Art">Textiles</option> </select> 

Answer 3

Better create options array, and work with data, not with HTML. Using this approach you will be able to stay DRY.

Think solution is clear.

<html>
<body>

<select type="select" name="optRes3" select id="optRes1">
    <option value="" disabled selected hidden>Please select an option...</option>
  <option value="Art">Art</option>
  <option value="Business Studies">Business Studies</option>
  <option value="Computing">Computing</option>
  <option value="Drama">Drama</option>
  <option value="French">French</option>
  <option value="Food Technology">Food Technology</option>
  <option value="Geography">Geography</option>
  <option value="German">German</option>
  <option value="History">History</option>
  <option value="Music">Music</option>
  <option value="Philosophy and Ethics">Philosophy and Ethics</option>
  <option value="Product Design">Product Design</option>
  <option value="Physical Education">Physical Education</option>
  <option value="Spanish">Spanish</option>
  <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option>
  <option value="Textiles">Textiles</option>
</select>
<select type="select" name="optRes3" select id="optRes2">
    <option value="" disabled selected hidden>Please select an option...</option>
  <option value="Art">Art</option>
  <option value="Business Studies">Business Studies</option>
  <option value="Computing">Computing</option>
  <option value="Drama">Drama</option>
  <option value="French">French</option>
  <option value="Food Technology">Food Technology</option>
  <option value="Geography">Geography</option>
  <option value="German">German</option>
  <option value="History">History</option>
  <option value="Music">Music</option>
  <option value="Philosophy and Ethics">Philosophy and Ethics</option>
  <option value="Product Design">Product Design</option>
  <option value="Physical Education">Physical Education</option>
  <option value="Spanish">Spanish</option>
  <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option>
  <option value="Textiles">Textiles</option>
</select>
<select type="select" name="optRes3" select id="optRes3">
    <option value="" disabled selected hidden>Please select an option...</option>
  <option value="Art">Art</option>
  <option value="Business Studies">Business Studies</option>
  <option value="Computing">Computing</option>
  <option value="Drama">Drama</option>
  <option value="French">French</option>
  <option value="Food Technology">Food Technology</option>
  <option value="Geography">Geography</option>
  <option value="German">German</option>
  <option value="History">History</option>
  <option value="Music">Music</option>
  <option value="Philosophy and Ethics">Philosophy and Ethics</option>
  <option value="Product Design">Product Design</option>
  <option value="Physical Education">Physical Education</option>
  <option value="Spanish">Spanish</option>
  <option value="Science (Triple)">Science (Triple Award - 3 GCSEs)</option>
  <option value="Textiles">Textiles</option>
</select>

<script>
function OptResDropdown(htmlDropdown, value) {
    this.value = value;
    this.dropdown = htmlDropdown;
    this.options = this.initOptions(htmlDropdown.options);
    var selected = htmlDropdown.options[htmlDropdown.selectedIndex];
    this.value = value? value : (selected ? selected.value : 0); 
    var me = this;
    htmlDropdown.addEventListener('change', function(event){
        me.value = event.target.value;
        me.update(me.value);
    });
    this.update();
}

OptResDropdown.instances = {};

OptResDropdown.prototype.initOptions = function(options){
    var me = this;
    var out = [];
    for(var i = 0; i < options.length; i++) {
        var option = options[i];
        out.push({value: option.value, label: option.innerText});
    }
    return out;
};

OptResDropdown.prototype.update = function(value) {
    for(var key in OptResDropdown.instances) {
        var me = OptResDropdown.instances[key];
        me.dropdown.innerHTML = '';
        var options;
        if(value === 'Art') {
            options = me.options.filter(function(option){
                return option.value !== 'Textiles';
            });
        } else if(value === 'Textiles') {
            options = me.options.filter(function(option){
                return option.value !== 'Art';
            });
        } else {
            options = me.options;
        }
        options.forEach(function(option){
            var opt = document.createElement('option');
            opt.value = option.value;
            opt.innerText = option.label;
            me.dropdown.appendChild(opt);
        })
        me.dropdown.value = me.value;
    }
};



var opt1 = new OptResDropdown(optRes1);
var opt2 = new OptResDropdown(optRes2);
var opt3 = new OptResDropdown(optRes3);

OptResDropdown.instances.opt1 = opt1;
OptResDropdown.instances.opt2 = opt2;
OptResDropdown.instances.opt3 = opt3;

</script>
</body>
</html>