javascript - 选择选项 1 时禁用选项 2

Question

我需要调整我为我工作的学校创建的网站所使用的一些代码，以禁止同时选择某些选项。

向用户显示以下 HTML 下拉列表 6 次:

<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>

用户不应同时选择艺术品和纺织品。他们可以选择艺术或纺织品 - 但不能同时选择两者。

例如:用户在 opt1 中选择“Art”，因此在其余 5 个菜单中禁用“Textiles”。如果用户返回并取消选择“艺术”，则应始终启用“纺织品”。希望你明白我的意思。

我已经有了防止多次选择同一选项的代码:

$(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);
                }
            });
        }
    });
});

然后用户单击“提交”，所有这些都会提交到 MySQL 服务器以供稍后审核。

菜单名为 opt1、opt2、opt3、opt4、optRes1 和 optRes2。

谢谢大家，

jack

Answer 1

我使用名为notallowed 的数据属性。您可以在那里设置应禁用的值。当值更改时，我们还会检查之前是否禁用了某些字段并重新启用它们。

$('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>