问题
I want to observe multiple select menus and respond to their changes using prototype but only the first menu seems to be observed. This is my code:
$('product_options').select('select').invoke("observe","change",optchange);
If there are - for example - 3 selects within product_options then it only observes the first, i thought it might be because of invoke so i then tried this:
$('product_options').select('select').each(function(sel){
$(sel).observe("change",optchange);
});
Still doesnt work though, any ideas whats wrong?
There's definitely nothing wrong with the selector as a console.debug() shows me all the select menus
回答1:
Have you checked your JS error console? The below works just fine:
<html>
<head>
<title>optchange</title>
<script type="text/javascript" src="prototype.js"></script>
</head>
<body>
<div id="product_options">
<select id="o0">
<option>1</option>
<option>2</option>
</select>
<select id="o1">
<option>1</option>
<option>2</option>
</select>
<select id="o3">
<option>1</option>
<option>2</option>
</select>
</div>
<script type="text/javascript">
function optchange(e) {
alert("optchanged");
}
$('product_options').select('select').invoke("observe","change", optchange);
</script>
</body>
</html>
来源：https://stackoverflow.com/questions/2995777/observing-multiple-select-menus-with-prototype