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Return Content with alert in Controller

I'm trying to somewhat replicate what I saw in this question, particularly in this answer, but not quite the same.
My intent is, if the zip has no files (it can happen because the folder could be empty) I want to return an alert just so the user is warned that is not possible to obtain the file at the time.
But I'm missing on the redirection point, I don't want the alert to redirect the user to a blank page refering the Action, I want it to stay in the page, also due to some filters.
Is this possible? I couldn't find anything that would stop the redirection from happening.
Here is my the Action Controller code:
public ActionResult DownloadZip(List<int> things)
{
// Create zip with files
if (!zip.Any())
{
return Content(#"<script language='javascript' type='text/javascript'>
alert('Message');
</script>
");
}
// Return zip
}
Here is the call from the view:
$("#btnExportToZip").on("click", function (e) {
var grid = $("#gridThings").data("kendoGrid");
var items = grid.dataSource.data();
var lstIds = [];
$.each(items, function (index, elem) {
if (elem.Checked) {
lstIds.push(elem.Id);
}
});
if (lstIds.length > 0) {
var params = lstIds.join("&listAmostras=")
var url = '/Search/DownloadZip?listAmostras=' + params;
window.location.href = url;
}
});

If you do a redirect as you're doing here, it's too late to take it back once you've determined the zip file is empty. Your best bet here is probably to do an AJAX file download. Bear in mind, though, that this will require that the browser supports the HTML5 File API, so IE 9 and under are out.
$.ajax({
url: url,
async: false,
xhrFields: {
responseType: 'blob'
},
success: function (data) {
var a = document.createElement('a');
var url = window.URL.createObjectURL(data);
a.href = url;
a.download = 'myfile.pdf';
a.click();
window.URL.revokeObjectURL(url);
}
});
Essentially what this does is request the zip file via AJAX. Once the file data has been received, an anchor link is added to the DOM (not visible) and dynamically "clicked" to approximate the behavior of user click a link to a static file. In other words, a download prompt will pop as soon as the AJAX request completes successfully. However, this code only removes the need to redirect. You still need to conditionally pop the download only if the zip file has something in. There's two ways you can accomplish that.
In the success callback of the AJAX, you would wrap the code there in a conditional that checks that data.size > 0. However, that might not actually work. I've never looked at an empty zip file, but it's entirely possible that there's file headers in the binary that would cause the blob to actually have a size greater than zero, even though it's "empty".
The better approach is to return an error response in your zip action when the zip file is empty. Off the top of my head, I'm not sure what the most appropriate error response code would be, but anything in 400-500 range will work for triggering the appropriate AJAX callback. Then, you just need to add and error handler to this AJAX. In that handler, you could then notify the user however you like that there's no download because the zip would be empty.

As per my understanding, alert is redirect the user to the blank page because in the javascript you have the line window.location.href = url; which might be redirect to the same action again which shows the alert.
So try to give the different url to the window.location.href
for ex:window.location.href = '../somecontroller/someaction';
thanks
Karthik

Opening up new tab based on ajax response - Angular JS

On clicking a hyperlink,
{{id}}
I require something to open up in a new tab based upon the response (a flag, lets say - responseFlag) that I get from the ajax call.
Two methods I tried.
Note : Function is dependent on the id, so not using it on page load.
1.
$http.get(url).success(function(response) {
if(response.data.responseFlag==true){
$window.open("http://www.example.com");
}
else{
//perform something else other that window.open
}
});
The problem here is the 'Popup blockers' in the browsers (Chrome, Mozilla) - that keeps blocking them.
2.
var w = $window.open("","_blank");
$http.get(url).success(function(response) {
if(response.data.responseFlag == true){
w.location = "http://www.example.com";
}
else{
//perform something else
}
});
Here, if the 'responseFlag = true', it opens up in new tab. But as you might have guessed it, for 'responseFlag = false' too the tab opens up. I can use w.close() in the 'else' perhaps. But I think that's not a solution.
Help me out friends !

In your second example you're openning the new tab before doing the request, so it doesn't matter wich callback gets executed, you'll get a new window openned.
I don't see any reason why $window.open(...) works with your second example but not in the first, maybe is because the "_blank" parameter...
So, can you try this way?
$http.get(url).success(function(response) {
if(response.data.responseFlag == true){
var w = $window.open("","_blank");
w.location = "http://www.example.com";
}
else{
//perform something else
}
});

What's the best way to force a hashchange?

My website uses hashchange-triggered AJAX (to make it more bookmark-friendly). The problem I am having is that when I click "submit" in a form, all the form data that is serialize()'d to be sent via $.post() gets lost. I know this because I get the "Flag 1" alert after I click submit, and various other tests (alerting, echoing, etc.) show this to be true.
Here's my current code:
$(document).ready(function() {
var data = '';
var hash = '';
newPage();
alert('Flag 1');
$(window).bind('hashchange', function() {
hash = window.location.hash;
if (hash == '') {
path = window.location.pathname;
hash = '#' + path.replace(/^\/+/, '');
}
data += '&func=' + hash;
var xhr = $.post(hash, data, function(result) {
$("maincontent").html(result);
})
.done(newPage);
});
// Initialize vars and handle new form elements
function newPage() {
data = '';
$('form').submit(function() {
data = $(this).serialize();
// Flag 2 - What do I do here?
});
}
// Load ajax content on first run of document
if ($('#maincontent').html() == '')
$(window).trigger('hashchange');
});
What I am trying to do is manually fire a hashchange event while also changing the URL. The trouble is that if I just set window.location.hash = $(this).attr('action'); then return false; where the "Flag 2" comment is, then I wind up getting unwanted trash in the URL, possibly due to the hashmark being encoded for a URL (...%23, etc).
I am wondering what the best way to set the hash is, and whether there is a simpler way to do what I am trying to do to begin with.
(I'm also open to comments suggesting alternate approaches for the style of navigation I am trying to achieve)

Well, I understand there are lots of errors doing this. But we have alternative options for this you will surely like:
jQuery History Plugin : http://plugins.jquery.com/history/ (Demo: http://4nf.org/)
History JS: https://github.com/browserstate/history.js/
But I would recommend HTML5 history.pushState if you are willing to avoid older browser support. (Demo: https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Manipulating_the_browser_history)
Good luck!!

JavaScript: How to open a returned file via AJAX

This is similar to: How to open a file using JavaScript?
Goal: to retrieve/open a file on an image's double click
function getFile(filename){
// setting mime this way is for example only
var mime = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document';
jQuery.ajax({ url : 'get_file.pl',
data : {filename:filename},
success : function(data){
var win = window.open('','title');
win.document.open(mime);
win.document.write(data);
win.document.close();
}
});
}
jQuery('#imgID').dblclick(function(){
getFile('someFile.docx');
});
I'm doing this off the top of my head, but I think the above would work for text files, but not binary. Is there a plugin that does this properly? The ideal would be to open the file in the browser (or application), rather than download, but I doubt that is a dream. If the file must be downloaded with the save/open dialog, that's fine.
Edit:
One piece of information that I forgot to mention is that I'd like this to be a POST request. This is partly why I was looking at AJAX to begin with. I've seen workarounds that have created forms/iframes to do something similar, but I was looking for a better handler of the returned info.

Seems to me there's no reason to do this via AJAX. Just open the new window to get_file.pl?filename=... and let the browser handle it. If the user has a plugin capable of handling the Content-Type sent by get_file.pl, the file will display; otherwise, it should download like any other file.
function getFile(filename) {
window.open('get_file.pl?filename=' + filename,'title');
}
jQuery('#imgID').dblclick(function() {
getFile('someFile.docx');
});
Edit: If you want to POST to your script, you can do it with some <form> hackery:
function getFile(filename) {
var win = 'w' + Math.floor(Math.random() * 10000000000000);
window.open('', win,'width=250,height=100');
var f = $('<form></form>')
.attr({target: win, method:'post', action: 'get_file.pl'})
.appendTo(document.body);
var i = $('<input>')
.attr({type:'hidden',name:'filename',value:filename})
.appendTo(f);
f[0].submit();
f.remove();
}
Of course, this is somewhat silly since it is impossible to hide your data from "prying eyes" with developer tools. If your filename really is sensitive, issue access tokens to the client, and look up the data in your sever script.

KDE plasmoid ind autorefresh

I'm trying to write KDE4 plasmoid in JavaScript, but have not success.
So, I need to get some data via HTTP and display it in Label. That's working well, but I need regular refresh (once in 10 seconds), it's not working.
My code:
inLabel = new Label();
var timer= new QTimer();
var job=0;
var fileContent="";
function onData(job, data){
if(data.length > 0){
var content = new String(data.valueOf());
fileContent += content;
}
}
function onFinished(job) {
inLabel.text=fileContent;
}
plasmoid.sizeChanged=function()
{
plasmoid.update();
}
timer.timeout.connect(getData);
timer.singleShot=false;
getData();
timer.start(10000);
function getData()
{
fileContent="";
job = plasmoid.getUrl("http://192.168.0.10/script.cgi");
job.data.connect(onData);
job.finished.connect(onFinished);
plasmoid.update();
}
It gets script once and does not refresh it after 10 seconds. Where is my mistake?

It is working just fine in here at least (running a recent build from git master), getData() is being called as expected. Can you see any errors in the console?
EDIT: The problem was that getUrl() explicitly sets NoReload for KIO::get() which causes it load data from cache instead of forcing a reload from the server. Solution was to add a query parameter to the URL in order to make it force reload it.