Java全局变量在onsubmit事件处理程序中不可更改

Question

I've attached onsubmit handler in a form tag like this:

<form action="file.php" method="post" onsubmit=" return get_prepared_build(this);" >

but whatever global variable (defined earlier, of course) I try to change inside get_prepared_build() function - later it apprears non-modified. Looks like that this function deals with a local copy of everything, even document property values are not saved.

Are there scope/visibility problems when javascript functions are called this way from tags/attributes?

Here is the function:

function give_link(results)
{
    document.title = 'visibility test';
    return false;
}

then below in the document I have

<script>alert('test' + document.title );</script>

As a result - in the window I have a new title, but the alert box displays old variable value.

Answer 1

To answer your last question, no, there are no scope/visibility problems when JavaScript functions are called from tags/attributes:

<script type="text/javascript">
var x = 'Hello';
function get_prepared_build(f) {
    alert('Start get_prepared_build: x=' + x + '; document.cookie=' + document.cookie);
    x = 'There';
    // deliberately invalid cookie for test purposes only
    document.cookie = 'test';
    alert('End get_prepared_build: x=' + x + '; document.cookie=' + document.cookie);
    return false;
}
</script>
<form action="file.php" method="post" onsubmit="var ret=get_prepared_build(this);alert('Outside get_prepared_build: x=' + x + '; document.cookie=' + document.cookie);return ret;">
<input type="submit">
</form>

As was mentioned in comments, a sample of code demonstrating your specific problem would be helpful.

EDIT: In your example, the function that updates document.title is never invoked, or is invoked after you alert() the current value, so document.title doesn't appear to change.

<script type="text/javascript">
function changeDocumentTitle(f) {
    // this only runs onsubmit, so any alert()s at the bottom
    // of the page will show the original value before the
    // onsubmit handler fires
    document.title = 'new value';
    return false;
}
</script>
<form onsubmit="return changeDocumentTitle(this);">
<input type="submit">
</form>
<script type="text/javascript">
// this executes when the page loads, so it will show
// the value before any onsubmit events on the page fire
alert(document.title); // original value
</script>