我有以下 div 类“labouritems”，每次用户单击按钮时，它都会将一个新实例插入到 dom 中。
我需要能够计算“.rate”和“.hours”字段并将答案设置为“.total”字段。
现在这仅适用于用户正在处理的“labouritems”实例，即：不应该更新另一个实例上的字段总计，所以基本上只在该行内工作。
下面是我正在使用的 html，下面是我拥有的代码，它仅适用于“labouritems”的第一个实例，但是当我插入一个新实例时，它不会做任何事情。
<div class="labouritems">
<label for="quote_labouritems_attributes_0_description">Description</label>
<input class="input-medium" id="quote_labouritems_attributes_0_description" name="quote[labouritems_attributes][0][description]" size="30" type="text" value="concrete the house">
<label for="quote_labouritems_attributes_0_hours">Hours</label>
<input class="input-mini hours" id="quote_labouritems_attributes_0_hours" name="quote[labouritems_attributes][0][hours]" size="30" type="text" value="33">
<label for="quote_labouritems_attributes_0_total">Total</label>
<input class="input-mini total" id="quote_labouritems_attributes_0_total" name="quote[labouritems_attributes][0][total]" size="30" type="text" value="1089">
<label for="quote_labouritems_attributes_0_Mup/Hr">Mup/hr</label>
<input class="input-mini" id="quote_labouritems_attributes_0_muphourrate" name="quote[labouritems_attributes][0][muphourrate]" size="30" type="text" value="0">
<label for="quote_labouritems_attributes_0_Mup/Total">Mup/total</label>
<input class="input-mini" id="quote_labouritems_attributes_0_muptotal" name="quote[labouritems_attributes][0][muptotal]" size="30" type="text" value="0">
<label for="quote_labouritems_attributes_0_Mup/%">Mup/%</label>
<input class="input-mini" id="quote_labouritems_attributes_0_muppercent" name="quote[labouritems_attributes][0][muppercent]" size="30" type="text">
<label for="quote_labouritems_attributes_0_Contractor">Contractor</label>
<input class="input-small" data-autocomplete="/contractors/autocomplete_contractor_firstname" data-update-elements="{"id":"#quote_labouritems_attributes_0_contractor_id","hourly_rate":"#quote_labouritems_attributes_0_contractor_rate"}" id="quote_labouritems_attributes_0_contractor_name" name="quote[labouritems_attributes][0][contractor_name]" placeholder="Seach" size="30" type="text" value="bing lee">
<input id="quote_labouritems_attributes_0_contractor_id" name="quote[labouritems_attributes][0][contractor_id]" type="hidden" value="1">
<label for="quote_labouritems_attributes_0_Rate/hr">Rate/hr</label>
<input class="input-mini rate" id="quote_labouritems_attributes_0_contractor_rate" name="quote[labouritems_attributes][0][contractor_rate]" size="30" type="text" value="33">
<label for="quote_labouritems_attributes_0_Work %">Work %</label>
<input class="input-mini" id="quote_labouritems_attributes_0_progress_percent" name="quote[labouritems_attributes][0][progress_percent]" size="30" type="text" value="55">
<label for="quote_labouritems_attributes_0_Work $">Work $</label>
<input class="input-mini" id="quote_labouritems_attributes_0_progress_payment" name="quote[labouritems_attributes][0][progress_payment]" size="30" type="text">
<input id="quote_labouritems_attributes_0__destroy" name="quote[labouritems_attributes][0][_destroy]" type="hidden" value="false"><a href="javascript:void(0)" class="btn btn-small btn-danger remove_nested_fields" data-association="labouritems">Delete</a>
</div>
var LabourItems = {
rate: null,
hours: null,
total: null,
init: function(object) {
this.rate = parseInt($(object).children('.rate').first().val(), 10);
// var rate = $(object).children('.rate').first();
this.hours =parseInt($(object).children('.hours').first().val(), 10);
this.total = this.rate * this.hours;
this.updateTotal(object);
},
updateTotal: function(object) {
$(object).children('.total').first().val(this.total || 0);
}
}
//reactTochange for those inputs that you want to observe
$('.hours').on("keyup", function() {
$('.labouritems').each( function(key,value){
LabourItems.init(this);
});
});