Bug in Safari: options.length = 0; not working as expected in Safari 4
This is not a real question, but rather an answer to save some others the hassle of tracking this nasty bug down. I wasted hours finding this out.
When using options.length = 0;
to reset all options of a select element in safari, you can 开发者_JS百科get mixed results depending on wether you have the Web Inspector open or not.
If the web inspector is open you use myElement.options.length = 0;
and after that query the options.length()
, you might get back 1 instead of 0 (expected) but only if the Web Inspector is open (which is often the case when debugging problem like this).
Workaround:
Close the Web Inspector or call myElement.options.length = 0;
twice like so:
myElement.options.length = 0;
myElement.options.length = 0;
Testcase:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Testcase</title>
<script type="text/javascript" language="javascript" charset="utf-8">
function test(el){
var el = document.getElementById("sel");
alert("Before calling options.length=" + el.options.length);
el.options.length = 0;
alert("After calling options.length=" + el.options.length);
}
</script>
</head>
<body onLoad="test();">
<p>
Make note of the numbers displayed in the Alert Dialog, then open Web inspector, reload this page and compare the numbers.
</p>
<select id="sel" multiple>
<option label="a----------" value="a"></option>
<option label="b----------" value="b"></option>
<option label="c----------" value="c"></option>
</select>
</body>
</html>
Close the Web Inspector or call myElement.options.length = 0; twice like so:
myElement.options.length = 0;
myElement.options.length = 0;
Can't reproduce that with current dev-channel version. 5.0.375.6
Try:
myElement.options.splice(0, myElement.options.length);
(first param is the starting index, second param indicates how many elements to delete)
精彩评论