如何在materialize css框架中动态修改<select>

Question

我刚开始使用materialize css框架.现在,materialize将任何select标签转换为ul和li元素的集合.之前,使用JQuery,我能够做到这一点:

var $selectDropdown = $("#dropdownid");
$selectDropdown.empty();
$selectDropdown.html(' ');
var value = "some value";
$selectDropdown .append($("<option></option>").attr("value",value).text(value));

我的html只是一个示例选择标记:

以前,这是有效的.现在它失败了.使用javascript动态重新填充此下拉列表的替代方法是什么？

Answer 1

根据物化形式文件:

此外,您需要单独调用页面生成的任何动态生成的选择元素

因此,最好的方法是通过额外的调用重新绑定生成的选择.material_select().

为了可重用,您可以在元素更改时设置侦听器,然后在更新原始选择时触发侦听器

// 1) setup listener for custom event to re-initialize on change
$('select').on('contentChanged', function() {
  $(this).material_select();
});

// 2a) Whenever you do this --> add new option
$selectDropdown.append($("<option></option>"));

// 2b) Manually do this --> trigger custom event
$selectDropdown.trigger('contentChanged');

这样做的好处是只需要更新已更改的特定select元素.

jsFiddle和Stack Snippets中的演示:

$(function() {

  // initialize
  $('.materialSelect').material_select();

  // setup listener for custom event to re-initialize on change
  $('.materialSelect').on('contentChanged', function() {
    $(this).material_select();
  });

  // update function for demo purposes
  $("#myButton").click(function() {
    
     // add new value
    var newValue = getNewDoggo();
    var $newOpt = $("<option>").attr("value",newValue).text(newValue)
    $("#myDropdown").append($newOpt);

    // fire custom event anytime you've updated select
    $("#myDropdown").trigger('contentChanged');
    
  });

});

function getNewDoggo() {
  var adjs =  ['Floofy','Big','Cute','Cuddly','Lazy'];
  var nouns = ['Doggo','Floofer','Pupper','Fluffer', 'Nugget'];
  var newOptValue = adjs[Math.floor(Math.random() * adjs.length)] + " " + 
                    nouns[Math.floor(Math.random() * nouns.length)];
  return newOptValue;
}

body { padding: 25px}

<link  href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/css/materialize.min.css" rel="stylesheet">
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/js/materialize.min.js"></script>

<button class="waves-effect waves-light btn" id="myButton">
  Add New Option to Dropdown
</button>

<select id="myDropdown" class="materialSelect">
  <option value="Happy Floof">Happy Floof</option>
  <option value="Derpy Biscuit">Derpy Biscuit</option>
</select>

Answer 2

成功绑定数据后,可以重新初始化select元素.像这样,

$('select').material_select();

与此类似:

var next_id = $(".mtr-select");
$.each(json, function(key, value) {
    $(next_id).append($("<option></option>").attr("value", value.id).text(value.name));
});
$(next_id).material_select();

它ul>li通过在加载时创建dom对象将其选项值绑定到新元素.

Answer 3

这是MaterialiseCss v0.96.1的有效解决方案.在版本0.97.0中它不起作用:似乎有一个错误在HTML中附加插入符号.

这里的代码为v0.97.0:

$(document).ready(function() {

  // Initialize
  $('select').material_select();
  
  $("button").click(function() {
    
    // Clear the content
    $("select").empty().html(' ');

    // And add a new value
    var value = "New value";
    $("select").append(
      $("<option></option>").attr("value",value).text(value)
    );

    // Update the content clearing the caret
    $("select").material_select('update');
    $("select").closest('.input-field').children('span.caret').remove();
  });

 
});

<link  href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.97.0/css/materialize.min.css" rel="stylesheet">
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.97.0/js/materialize.min.js"></script>

<button class="btn-large blue waves-effect waves-light">Change</button>

<div class="input-field">

    <select>
      <option>Option 1</option>
      <option>Option 2</option>
      <option>Option 3</option>
    </select>

</div>