在动态添加的输入中计算值 [英] calculating values in dynamically added inputs
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问题描述
我正在尝试建立一个电话帐单计算器，允许用户动态添加额外的行。每行将具有3个字段：瓦数，每天使用的小时数和瓦特数*小时的总和。一切都在第一行工作正常，但是当我尝试动态添加额外的行时，我的代码仍然适用于第一个产品，并给我一个NaN。理想情况下，一旦完成添加行，我将总计千瓦时的小时数。以下粘贴到目前为止：
I'm trying to build a utility bill calculator that allows for the user to dynamically add additional lines. each line will have 3 fields: wattage, hours used per day, and the total of wattage*hours. everything works fine on the first line, but when I try to dynamically add additional lines, my code still works with the first product and gives me a NaN. ideally once they're done adding rows, I would sum the total kilowatt hours at the bottom. Pasted below is what I have so far:
<html>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
var maxField = 30; //Input fields increment limitation
var addButton = $('.add_button'); //Add button selector
var wrapper = $('.field_wrapper'); //Input field wrapper
var fieldHTML = '<div>Wattage: <input type="text" name="field_wattage" value="300" size=4 maxlength="4" onchange="product()"> Hours Per Day Used: <select name="field_hour" onchange="product()"><option value="01"> 01</option><option value="02"> 02</option><option value="03"> 03</option><option value="04"> 04</option><option value="05"> 05</option><option value="06"> 06</option><option value="07"> 07</option><option value="08"> 08</option><option value="09"> 09</option><option value="10"> 10</option><option value="11"> 11</option><option value="12"> 12</option><option value="13"> 13</option><option value="14"> 14</option><option value="15"> 15</option><option value="16"> 16</option><option value="17"> 17</option><option value="18"> 18</option><option value="19"> 19</option><option value="20"> 20</option><option value="21"> 21</option><option value="22"> 22</option><option value="23"> 23</option><option value="24"> 24</option></select> Daily Wattage: <INPUT TYPE="text" ID="dailyproduct" NAME="result" VALUE=""/><a href="javascript:void(0);" class="remove_button" title="Remove field"> Remove Line</a></div>'; //New input field html
var x = 1; //Initial field counter is 1
$(addButton).click(function(){ //Once add button is clicked
if(x < maxField){ //Check maximum number of input fields
x++; //Increment field counter
$(wrapper).append(fieldHTML);
// Add field html
}
});
$(wrapper).on('click', '.remove_button', function(e){ //Once remove button is clicked
e.preventDefault();
$(this).parent('div').remove(); //Remove field html
x--; //Decrement field counter
});
});
</script>
<script type="text/javascript">
function product()
{
var num1 = document.myform.field_wattage.value;
var num2 = document.myform.field_hour.value;
var myproduct = parseInt(num1) * parseInt(num2);
document.getElementById('dailyproduct').value = myproduct;
}
</script>
<?php
echo "<br>";
echo "</select>";
echo "<br>";
$dateStart = mktime(0, 0, 0, 03, 01);
$dateEnd = mktime(0, 0, 0, 10, 31);
if (time() < $dateEnd && time() > $dateStart)
// show stuff
echo "You are in Peak Hours";
else
echo "You are in Off Peak Hours";
?>
<body>
<FORM NAME="myform">
<br />
<br />
<br />
<div class="field_wrapper">
<div>
Wattage:
<input type="text" name="field_wattage" value="300" size=4 maxlength="4" onchange="product()">
</select> Hours Per Day Used:
<select name="field_hour" onchange="product()"/>
<option value="01"> 01</option>
<option value="02"> 02</option>
<option value="03"> 03</option>
<option value="04"> 04</option>
<option value="05"> 05</option>
<option value="06"> 06</option>
<option value="07"> 07</option>
<option value="08"> 08</option>
<option value="09"> 09</option>
<option value="10"> 10</option>
<option value="11"> 11</option>
<option value="12"> 12</option>
<option value="13"> 13</option>
<option value="14"> 14</option>
<option value="15"> 15</option>
<option value="16"> 16</option>
<option value="17"> 17</option>
<option value="18"> 18</option>
<option value="19"> 19</option>
<option value="20"> 20</option>
<option value="21"> 21</option>
<option value="22"> 22</option>
<option value="23"> 23</option>
<option value="24"> 24</option>
</select>
Daily Wattage:
<INPUT TYPE="text" ID="dailyproduct" NAME="dailyproduct" VALUE=""/>
<INPUT TYPE="button" NAME="button" Value="=" onClick="product()"/>
<a href="javascript:void(0);" class="add_button" title="Add field"> Add Line</a>
</div>
</div>
</FORM>
</div>
</body>
</html>
我早上在这里搜索过，没有找到任何描述我的问题的内容。感谢提前。
I've searched on here all morning and haven't found anything that quite describes my issue. Thanks in advance.
推荐答案
我在下面创建了一个工作示例。正如我在评论中所说的那样，你是通过名称引用字段，当页面上有同样的字段时，这些字段不起作用。
I created a working example below. As I stated in the comments, you are referencing fields by name, and that doesn't work when there are fields named the same on the page.
更现代化的方式，您应该使用事件委派，并确定要更新哪些字段在事件中。在这个例子中，我写了一个事件来处理选择和输入更改，然后我使用jQuery的 .closest（） 方法来帮助我找到需要更新。
To solve in a more modern way, you should use event delegation and determine which fields to update within the event. In the example, I have written one event to handle the select and input changes, then I use jQuery's .closest() method to help me find the fields that need to be updated.
$(document).ready(function(){
var maxField = 30; //Input fields increment limitation
var addButton = $('.add_button'); //Add button selector
var wrapper = $('.field_wrapper'); //Input field wrapper
var fieldHTML = '<div>Wattage: <input type="text" name="field_wattage" value="300" size=4 maxlength="4"> Hours Per Day Used: <select name="field_hour"><option value="01"> 01</option><option value="02"> 02</option><option value="03"> 03</option><option value="04"> 04</option><option value="05"> 05</option><option value="06"> 06</option><option value="07"> 07</option><option value="08"> 08</option><option value="09"> 09</option><option value="10"> 10</option><option value="11"> 11</option><option value="12"> 12</option><option value="13"> 13</option><option value="14"> 14</option><option value="15"> 15</option><option value="16"> 16</option><option value="17"> 17</option><option value="18"> 18</option><option value="19"> 19</option><option value="20"> 20</option><option value="21"> 21</option><option value="22"> 22</option><option value="23"> 23</option><option value="24"> 24</option></select> Daily Wattage: <INPUT TYPE="text" NAME="dailyproduct" VALUE=""/><a href="javascript:void(0);" class="remove_button" title="Remove field"> Remove Line</a></div>'; //New input field html
var x = 1; //Initial field counter is 1
$(addButton).click(function(){ //Once add button is clicked
if(x < maxField){ //Check maximum number of input fields
x++; //Increment field counter
$(wrapper).append(fieldHTML);
// Add field html
}
});
$(wrapper).on('click', '.remove_button', function(e){ //Once remove button is clicked
e.preventDefault();
$(this).parent('div').remove(); //Remove field html
x--; //Decrement field counter
});
});
$(".field_wrapper").on("change", "input,select", function() {
var parent = $(this).closest("div");
var num1 = parent.find('[name="field_wattage"]').val();
var num2 = parent.find('[name="field_hour"]').val();
var dailyproduct = parent.find('[name="dailyproduct"]');
var myproduct = parseInt(num1) * parseInt(num2);
dailyproduct.val(myproduct);
getTotal();
});
function getTotal() {
var total = 0;
$('[name="dailyproduct"]').each(function() {
total += (parseInt(this.value, 0) || 0);
});
$("#total").val(total);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class="field_wrapper">
<div>
Wattage:
<input type="text" name="field_wattage" value="300" size=4 maxlength="4" />
Hours Per Day Used:
<select name="field_hour">
<option value="01"> 01</option>
<option value="02"> 02</option>
<option value="03"> 03</option>
<option value="04"> 04</option>
<option value="05"> 05</option>
<option value="06"> 06</option>
<option value="07"> 07</option>
<option value="08"> 08</option>
<option value="09"> 09</option>
<option value="10"> 10</option>
<option value="11"> 11</option>
<option value="12"> 12</option>
<option value="13"> 13</option>
<option value="14"> 14</option>
<option value="15"> 15</option>
<option value="16"> 16</option>
<option value="17"> 17</option>
<option value="18"> 18</option>
<option value="19"> 19</option>
<option value="20"> 20</option>
<option value="21"> 21</option>
<option value="22"> 22</option>
<option value="23"> 23</option>
<option value="24"> 24</option>
</select>
Daily Wattage:
<INPUT TYPE="text" NAME="dailyproduct" VALUE=""/>
<a href="javascript:void(0);" class="add_button" title="Add field"> Add Line</a>
</div>
</div>
<label>
Total:
<input id="total" />
</label>
这篇关于在动态添加的输入中计算值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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