Grails file download does not initiate when called from remoteFunction - grails

In my Grails application, a user can click on a g:link which will call my controller to export certain data to a CSV file. This works with no problems.
I then moved that button to a jQuery dialog box and, when the button is clicked, I use
${remoteFunction(action:'export', onSuccess:'closeMe();', id:courseInstance?.id)}
to call the same controller method and close the dialog box. I've confirmed that the method is actually called, and the dialog box closes. The user is not prompted with the CSV dowmload, however. I'm assuming this has something to do with the remoteFunction, but I'm not really sure. Can anyone explain why this might happen, and a potential fix?
Thanks!

With AJAX requests you can't handle to download content as attachment and so it can't trigger the Save As dialog.
There are a couple of workarounds for this:
Use a plain g:link as before and bind the 'closeMe();' function to the 'click' event. The problem is that you have no control on error or success response.
Use an iframe: You can create a temporary invisible iframe and set its location to the URL of the file to download. It also has the backside of not controlling the success/error response.
The code could be the same as in this answer:
<script type="text/javascript">
function downloadURL(url) {
var iframe;
var hiddenIFrameID = 'hiddenDownloader';
iframe = document.getElementById(hiddenIFrameID);
if (iframe === null) {
iframe = document.createElement('iframe');
iframe.id = hiddenIFrameID;
iframe.style.display = 'none';
document.body.appendChild(iframe);
}
iframe.src = url;
}
</script>
And the link
Export

Related

PhoneGap InAppBrowser: open iOS Safari Browser

In our PhoneGap iOS application, we are using the InAppBrowser plugin to display some content, and we need to open a page in Safari from within the InAppBrowser.
How can we have links from within the InAppBrowser open in Safari?
From the phonegap documentation:
Opens a URL in a new InAppBrowser instance, the current browser instance, or the system browser.
var ref = window.open(url, target, options);
ref: Reference to the InAppBrowser window. (InAppBrowser)
url: The URL to load (String). Call encodeURI() on this if the URL contains Unicode characters.
target: The target in which to load the URL, an optional parameter that defaults to _self. (String)
_self: Opens in the Cordova WebView if the URL is in the white list, otherwise it opens in the InAppBrowser.
_blank: Opens in the InAppBrowser.
_system: Opens in the system's web browser.
So to answer your question, use:
window.open(your_url, '_system', opts);
Note that the domain will need to be white-listed.
Update 4/25/2014:
I think I kind of misunderstood the question (thanks to commenter #peteorpeter) -- you want to have some way to click a link in the InAppBrowser and have that open in the system browser (e.g. Mobile Safari on iOS). This is possible, but it will require some forethought and cooperation between the app developer and the person responsible for the links on the page.
When you create an IAB instance, you get a reference to it back:
var ref = window.open('http://foo.com', '_blank', {...});
You can register a few event listeners on that reference:
ref.addEventListener('loadStart', function(event){ ... });
This particular event is fired every time the URL of the IAB changes (e.g. a link is clicked, the server returns a 302, etc...), and you can inspect the new URL.
To break out into the system browser, you need some sort of flag defined in the URL. You could do any number of things, but for this example let's assume there's a systemBrowser flag in the url:
.....html?foo=1&systemBrowser=true
You'll look for that flag in your event handler, and when found, kick out to the system browser:
ref.addEventListener('loadStart', function(event){
if (event.url.indexOf('systemBrowser') > 0){
window.open(event.url, '_system', null);
}
});
Note that this is not the best method for detecting the flag in the url (could lead to false positives, possibly) and I'm pretty sure that PhoneGap whitelist rules will still apply.
Unfortunately target=_system does not work from within the InAppBrowser. (This would work if the link originated in the parent app, though.)
You could add an event listener to the IAB and sniff for a particular url pattern, as you mention in your comments, if that fit your use case.
iab.addEventListener('loadstart', function(event) {
if (event.url.indexOf("openinSafari") != -1) {
window.open(event.url, '_system');
}
}
The 'event' here is not a real browser event - it is a construct of the IAB plugin - and doesn't support event.preventDefault(), so the IAB will also load the url (in addition to Safari). You might try to handle that event within the IAB, with something like:
iab.addEventListener('loadstop', function(event) {
iab.executeScript('functionThatPreventsOpenInSafariLinksFromGoingAnywhere');
}
...which I have not tested.
This message is for clarification:
If you open an another with window.open by catching a link on loadstart, it will kill yor eventhandlers that assigned to first IAB.
For example,
iab = window.open('http://example.com', '_blank', 'location=no,hardwareback=yes,toolbar=no');
iab.addEventListener('loadstop', function(event) {console.log('stop: ' + event.url);});
iab.addEventListener('loaderror', function(event) { console.log('loaderror: ' + event.message); });
iab.addEventListener('loadstart', function(event) {
if (event.url.indexOf("twitter") != -1){
var ref2 = window.open(event.url, '_system', null);
}
});
When the second window.open executed, it will kill all the event listeners that you binded before. Also loadstop event will not be fired after that window.open executed.
I'm finding another way to avoid but nothing found yet..
window.open() doesn't work for me from within an InAppBrowser, whether or not I add a script reference to cordova.js to get support for window.open(...'_system'), so I came up with the following solution which tunnels the "external" URL back to the IAB host through the hashtag so it can be opened there.
Inside the InAppBrowser instance (I'm using AngularJS, but you can replace angular.element with jQuery or $ if you're using jQuery):
angular.element(document).find('a').on('click', function(e) {
var targetUrl = angular.element(this).attr('href');
if(targetUrl.indexOf('http') === 0) {
e.preventDefault();
window.open('#' + targetUrl);
}
});
Note that that's the native window.open above, not cordova.js's window.open. Also, the handler code assumes that all URLs that start with http should be externally loaded. You can change the filter as you like to allow some URLs to be loaded in the IAB and others in Safari.
Then, in the code from the parent that created the InAppBrowser:
inAppBrowser.addEventListener('loadstart', function(e) {
if(e.url.indexOf('#') > 0) {
var tunneledUrl = e.url.substring(e.url.indexOf('#') + 1);
window.open(tunneledUrl, '_system', null);
}
});
With this solution the IAB remains on the original page and doesn't trigger a back-navigation arrow to appear, and the loadstart handler is able to open the requested URL in Safari.

Using changePage to Open a Dialog - Data object not sent

$.mobile.changePage("verify.aspx", { transition: "pop", role: "dialog", data: $("#form1").serialize() });
I'm using the above syntax to open a dialog box and in trying to send the form data via the data argument, nothing is passed.
This is what's being passed in the query string when I open the dialog:
#&ui-state=dialog&ui-state=dialog
(as a side note, this call is originating from a button within another dialog, thus the two ui-state=dialog's)
As you can see, no form data. Any ideas what I can do to persist the data in the url?
Answering my own question:
Found that the data-url attribute of the dialog you request is injected w/ the relative url.
By doing something like:
$("#dialog").on("pagebeforecreate", function (evt) {
var urlObj = $.mobile.path.parseUrl($(this).attr("data-url"));
Will give you access to the url and thus the proper query string values.

File upload struts 2 with Ajax

I am uploading a file using struts 2 with jsp as front end, but I dont want to refresh the page after the file is uploaded, so i am using Ajax but with that I am not able to get the File object in action, it seems file upload needs form tag in jsp,and if I am submitting the form then the page gets refreshed.
I researched through the net but cant get many relevant results, it would be of great help if someone guides me through this, is there a way for it. Any help would really be appreciated.
Best regards
I suggest to use iframe for upload file instead of ajax,
Sample code for Upload Csv file using struts2 and iframe :
var file = $("#fileUpload").val();
if(file.indexOf(".") != -1 && file.substr(file.indexOf("."))==".csv"){
/* created IFrame For UPload file*/
var iframe = $('<iframe name="uploadIPAddressIFrame" id="uploadIPAddressIFrame" style="display: none" />');
$("body").append(iframe);
/* Set Form for submit iframe*/
var form = $('#ipPoolForm');
form.attr("action", "uploadCSVFile.do");
form.attr("target", "uploadIPAddressIFrame");
form.submit();
openDialog(title);
/* handle response of iframe */
$("#uploadIPAddressIFrame").load(function () {
response = $("#uploadIPAddressIFrame")[0].contentWindow.document.body.innerHTML;
$("#chkIPAddressDiv").html(response);
$("iframe#uploadIPAddressIFrame").remove();
});
After upload if you submit form then change target of form :
// Because of using iframe for upload set target value
$("#ipPoolForm").attr("target", "");

File download from JSF with a rendered response

I have some dynamically generated files which I want my JSF 2.0 app to download for the user. I've been able to get this working using the code found in the solution here :
Forcing a save as dialogue from any web browser from JSF application
and a command button in a form on the page
And that works fine except for one hitch. I'd like to be able to render a message back to the user on the initial page that tells them their file is being processed and to please wait. Obviously the responseComplete call stops that from happening. Is there some way to re-render the submitting page and send back a file from the same button?
No, you can't. You can send only one response back per request. Best what you could do is to use JavaScript to show an initially hidden div or something which contains the message during the onclick. But you'll have the problem that you cannot hide it whenever the download is completed.
An alternative is to store the file on temp disk and return a fullworthy JSF response wherein you display a download link which returns the file from temp disk by a standalone servlet.
I think you can use ajax to solve this. Call the method that creates the file from an ajax action and provide a javascript callback to handle the navigation or to show a layer or whatever
<script type="text/javascript">
function processEvent(data) {
if (data.status == "begin") {
showWaitingLayer();
} else if (data.status == "success") {
hideWaitingLayer();
showDownloadLink();
}
}
</script>
<h:commandLink action="#{myBean.createDocument}">
<f:ajax onevent="processEvent"/>
</h:commandLink>

Can you pick a browser target server-side?

I have a form that lets users select checks, and when submitted, creates a PDF, which opens in a new browser tab. It doesn't have any branding, and will probably open in a plugin anyway, so I don't want it taking over my site's tab. So I set the form's target to _blank.
But it's possible for the user to submit the form without enough information to create the PDF, in which case I flag the error (server-side) and re-render the form. But because I set the form's target, this re-render opens in a new tab as well, and that's not what I want - in this case, I want it to behave as if target were _top.
So the question is: Can I change the browser's rendering target server-side?
Yes, I know that this can be done with client-side JavaScript, but JS annoys me, and I have to do the validation server-side anyway. I may end up having to use it, but please don't suggest it as an answer - I'm more curious if what I'm attempting can even be done.
PS: I'm on Ruby on Rails 2.3.8, in case anyone knows a framework-specific solution.
A workaround on this problem would be to use the content-disposition header on the pdf, in order to force the file to be downloaded, and avoid the whole "target" approach..
Content-type: application/pdf
Content-Disposition: attachment; filename="downloaded.pdf"
No. This is a purely client-specific feature. As a matter of fact, it's quite possible to get a browser that supports only one window and where the target attribute would have simply no effect. There were even efforts to make this attribute disappear from future HTML standards completely (for instance, the XHTML branch had no such attribute).
The only overlap that I can think of between HTML and HTTP are the <meta http-equiv> tags (where HTML can affect otherwise HTTP-controlled behavior). HTTP is a transfer protocol, designed to work with about just any kind of data. Letting it control presentation would be a pretty terrible mix of concerns.
Fortunately, we live in a JavaScript-enabled world. It is rather easy to validate a form using an AJAX request, especially with libraries like jQuery.
For instance, this script performs a POST request to an URL (in this case, /pdf/validate) and expects the page to send back "ok" (if everything's good) or something else if there was an error.
<form method="post" action="/pdf/send" id="pdf-form">
<!-- form stuff here -->
</form>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready(function()
{
// set to true if we are to bypass the check
// this will happen once we've confirmed the parameters are okay
var programmaticSubmit = false;
// attach an event handler for when the form is submitted
// this allows us to perform our own checks beforehand; we'll do so by
// cancelling the event the user triggered, and do the submit ourselves if
// we detect no error
$('#pdf-form').submit(function(event)
{
if (!programmaticSubmit)
{
// first off, cancel the event
event.preventDefault();
// do an AJAX request to /pdf/validate
$.ajax("/pdf/validate", {
type: "POST",
data: $(this).serialize(), // send the form data as POST data
success: function(result)
{
// this gets called if the HTTP request did not end
// abnormally (i.e. no 4xx or 5xx status);
// you may also want to specify an "error" function to
// handle such cases
if (result == "ok")
{
// since the server says the data is okay, we trigger
// the event again by ourselves, but bypassing the
// checks this time
programmaticSubmit = true;
$(this).submit();
}
else // something went wrong! somehow display the error
alert(result);
}
});
}
});
});
</script>

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