jQuery在动态创建的div中选择动态类ID

Question

I have some JS that dynamically creates a new div (inputs inside of a form). It works great. I separately have some jquery that checks a dropdown input, and shows a separate div if a specific selection is clicked. It works great.

If I try to use the jquery to show a separate div inside one of the dynamically created ones, it does not work. The first instance of it does work, but none of the dynamically created ones. After searching around, it looks like I need a delegation, but I can't seem to figure it out for my specific situation.

The JSFiddle: http://jsfiddle.net/Xyzeg/ (change the "CPI" dropdown in the first field, for the event to go off). The fiddle includes the other JS for dynamically creating the divs.

Any pointers would be appreciated.

<div style="float:left">
<div id='dynamicInput'>Pension 1: Amount: $<input type='text' name='adjustmentInputs[]' value='0' size='13' maxlength='20'>Start Year:
<input type='text' name='adjustmentInputs[]' value='2032' size='5' maxlength='6'>
<input type='hidden' name='adjustmentInputs[]' value='2100'>
<select name='adjustmentInputs[]'>
  <option value='InflationAdjusted'>Inflation Adjusted</option>
  <option value='NotInflationAdjusted'>Not Inflation Adjusted</option>
</select>by
<select name='adjustmentInputs[]' class='pensionAdjustment1'>
  <option value='CPI'>CPI</option>
  <option value='constantPercentage'>Constant %</option>
</select>
<div id='constantPercentageText1' style='display: none'>@ <input type='text' name='adjustmentInputs[]' value='3' size='5' maxlength='6'>%</div>
</div>
   <input type="button" value="Add another Portfolio Adjustment" onClick="addInput('dynamicInput');">
</div>
<script>
$("[class*=pensionAdjustment]").change(function() {
    var n = $(this).attr('class').replace('pensionAdjustment', '');
    var newId = "constantPercentageText" + n;
    var selectedItem = $(this).children('option:selected');
    if ($(this).val() == 'constantPercentage') {
        $("#constantPercentageText" + n).css('display', 'inline');
        $("#constantPercentageText" + n).show();
    } else {
        $("#constantPercentageText" + n).css('display', 'none');
    }
});  
</script>

Answer 1

You need to delegate with newly created elements!

Change this line

$("[class*=pensionAdjustment]").change(function() {

to

$(document).on('change',"[class*=pensionAdjustment]",  function() {

Answer 2

You can use

$(document).on('change', '[class*=pensionAdjustment]', function(){
    // your code
});

It would be better if you use a parent div, instead of document .

Update : The elements you are injection dynamically to the DOM were not present when the event was registered, so new elements are not firing the event. Using event delegation , (registering the event on a parent element) this could be solved because when any element fires an event, the event bubbles up to the last element (upwards) it can find and this way the parent element is being triggered but behind the scene, something like following is happening

e = e || window.event;
var el = e.target || e.srcElement;

You may check this .

Answer 3

You have to bind the event to a parent element, then filter down to the one you want. This way it doesn't matter when the element is added, it will always work. This is called delegation. You delegate the task of handling the event to another element.

$(document).on('change', "[class*=pensionAdjustment]", function(){
    var n = $(this).attr('class').replace('pensionAdjustment', '');
    var newId = "constantPercentageText" + n;
    var selectedItem = $(this).children('option:selected');
    if ($(this).val() == 'constantPercentage') {
        $("#constantPercentageText" + n).css('display', 'inline');
        $("#constantPercentageText" + n).show();
    } else {
        $("#constantPercentageText" + n).css('display', 'none');
    }
});