Primefaces upload, how to only allow one upload in advance mode - jsf

Question

I am wondering if it possible, by using the primefaces upload in advance mode to limit the user uploading one file only, currently i have :
<p:fileUpload fileUploadListener="#{fileUploadController.handleFileUpload}"
mode="advanced"
multiple="false"
update="messages"
sizeLimit="100000000"
allowTypes="/(\.|\/)(gif|jpe?g|png|doc|docx|txt|pdf)$/"
auto="false"/>
<p:growl id="messages" showDetail="true"/>
as you can see i have muliple ="false" but a user is still able to upload multiple files, any tips ?
EDIT :
<p:fileUpload widgetVar="upload" fileUploadListener="#{fileUploadController.handleFileUpload}"
mode="advanced"
multiple="false"
update="messages"
label="Select File"
sizeLimit="100000000"
allowTypes="/(\.|\/)(gif|jpe?g|png|doc|docx|txt|pdf|html)$/"
auto="false"/>
<p:growl id="messages" showDetail="true"/>
have added the widgetVar above
and in my js
<script type="text/javascript">
function Naviagtion()
{
//alert("Sent to the printing holding queue, you may close this app now, your work will still print out ");
window.setTimeout(afterDelay, 500);
location.href = 'FilesUploaded.xhtml';
}
upload.buttonBar.find('input[type=file]').change(function() {
if (this.value) {
var files = upload.uploadContent.find('.files tr');
if (files.length > 1) {
files.get(0).remove();
}
}
});
</script>
but i am still able to multi upload, am i going about this in the right direction

Answer 1

Although better behavior to solve it should be as #BalusC suggested, but in primefaces 4.0 I am seeing the attribute
fileLimit="1"
which you can set to 1 to disallow multiple file additions using "Choose" button. When user adds more file then it simply says
"Maximum number of files exceeded"

Answer 2

The multiple="false" only tells the webbrowser to disable multiple file selection in the browser-specific Browse dialog. However, it indeed doesn't prevent the enduser from clicking multiple times on the Choose button of the PrimeFaces file upload section to browse and add a single file multiple times.
Your best bet is to bring in some JS/jQuery to remove all previously selected files when a new file is selected. Provided that you have given your <p:fileUpload> a widgetVar="upload", then this should do:
$(document).ready(function() {
upload.buttonBar.find('input[type=file]').change(function() {
if (this.value) {
var files = upload.uploadContent.find('.files tr');
if (files.length > 1) {
files.get(0).remove();
}
}
});
});
Works for me on PrimeFaces 3.5.

Answer 3

If you have file limit set to 1 and some error happens while file is loading - you have to refresh the page to get file upload work again. If you don't refresh the page you get out of limit error message.
I used solution with JS, like in accepted answer,but have to change selectors, because wigetWar did not work for me.
In my view i have :
<p:fileUpload id="objectUpload"... />
In my portlet theme, table with files has a css class of "ui-fileupload-files".
$(document).ready(function() {
$("div[id*='objectUpload']").find('input[type=file]').change(function() {
if (this.value) {
var files = $("div[id*='objectUpload']").find('.uifileupload-files tr');
if (files.length > 1) {
files.get(0).remove();
}
}
});
});
Hope it helps.I used PrimeFaces 6.0