Downloading data posted to server as a file from Flex - apache-flex

This should be trivial, and I'm pretty sure I did it once before.
I'm trying to post data up to a server and have it bounced back to me as a file download, prompting the native browser file download box. I know the server part works just fine becasue I can post from a demo web form, but when I run the following Flex 3 code, I can't even get the request to fire.
var fileRef:FileReference = new FileReference();
private function saveXmlAsFile(event:MouseEvent):void
{
var fileRequest:URLRequest = new URLRequest();
fileRequest.method = URLRequestMethod.POST;
fileRequest.url = "http://foo.com/dataBounce";
var urlVariables:URLVariables = new URLVariables();
urlVariables.content = "Test content to return" ;
// fileRequest.contentType = "application/x-www-form-urlencoded ";
urlVariables.fileName = "test.xml";
fileRef.addEventListener(SecurityEvent.ALL, onSecurityError);
fileRef.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onSecurityError2);
fileRef.addEventListener(IOErrorEvent.NETWORK_ERROR, onNetworkError);
fileRef.addEventListener(Event.COMPLETE, onComplete);
try
{
fileRef.download(fileRequest, "test.xml");
}catch(error:Error) {
model.logger.error("unable to download file");
}
}
Note, when the call to fileRef.download is called, I can't see any request being made across the network using the traditional Firebug or HTTPWatch browser tools.
EDIT: I should add that this is for < Flash Player 10, so I can't use the newer direct save as file functionality.
Any suggestions? Thanks.

You need to add fileRef.upload to trigger the upload.
Also I would move the download statement to the onComplete so the file isn't requested before it's been uploaded.

Your explanation is pretty clear, but when I look at your code, I'm feel like I'm missing something.
The code looks like you're trying to do half of the upload part and half of the download part.
I think the code you currently have posted would work to trigger a download if you set the .method value to GET. I believe you will also need to include the filename as part of the .url property.
However, to post something and then trigger a download of it, you need two separate operations - the operation to post the data and then an operation to download it, which should probably be called from the upload operation's onComplete handler.

OK, I believe I figured out one of the things that's going on.
When you don't set the URLRequest.data property, it defaults the request method to "GET".
So, the working code looks like, with the data set to the posted URL variables:
private var fileRef:FileReference;
private function saveRawHierarchy(event:MouseEvent):void
{
var fileRequest:URLRequest = new URLRequest();
fileRequest.method = URLRequestMethod.POST;
fileRequest.url = "http://foo/bounceback";
var urlVariables:URLVariables = new URLVariables();
urlVariables.content = "CONTENT HERE";
urlVariables.fileName = "newFileName.xml";
fileRequest.data = urlVariables;
fileRef = new FileReference();
fileRef.addEventListener(Event.COMPLETE, onComplete);
try
{
fileRef.download(fileRequest, "appHierarchies.xml");
}catch(error:Error) {
model.logger.error("unable to download file");
}
}
Not sure what was wrong about the request not being made before, though.

Related

FileReference.upload non asynchronous?

I'm a bit of a flex noob, but I couldn't find this question asked anywhere, or a proper workaround. I'm quite used to GET/POST and web interactions, but I'm new to working in mxml's and such. See function below.
private function uploadFileSelect(event:Event):void
{
var uploadURL:String = Application.application.parameters.UploadURL;
var urlStr:String = ExternalInterface.call('window.location.href.toString');
var queryMap:Object = getQueryParams(urlStr);
var request:URLRequest = new URLRequest(uploadURL);
var urlVars:URLVariables = new URLVariables();
urlVars.appid = queryMap.appid;
urlVars.str = queryMap.str;
request.method = "POST";
request.data = urlVars;
uploadFileRef.upload(request);
}
Essentially, this works perfectly for what I need, with one exception. The final call to .upload is asynchronous, so I stay on the current page, but it calls the upload URL in the background. I want it to act like a form and actually navigate TO the upload URL with the POST data. I feel like this should be a simple solution, but I was kind of thrown the task of working on someone else's flash code and need a little advice.
Thanks in advance!
Because it is asynchronous, you cannot achieve redirect from the UI like you do in Html form. As a work around you can add listeners to the uploadFileRef
uploadURL = "someurl";
uploadFileRef.addEventListener(Event.complete, function(e:Event){
navigateToURL(new URLRequest(uploadURL),'_self')
});
navigate url will tke you to the target url. I do not know how you will get the uploadURL, i'm assuming it is the url at which you have uploaded the file to.

Flex URLRequest

I have some code written by another person. It's uploading a file to a server. I want to post simillar request but without sending a file (my version will copy file of a given name). I can't use method file.Upload(...). So what function I can use?
This is a code of request with file:
var request:URLRequest = new URLRequest(ApiConfig.ApiUrl);
request.method = URLRequestMethod.POST;
request.data = params;
try
{
_fileRef.upload(request);
}
catch(error:Error)
{
Alert.show(error.message);
}
I simply whant to make simillar request, but without uploading file and not using file instance.
I think it's pretty much dumb question but I don't know how to do this.

Is it possible to load a local file without having to ask the user to browse to it first in an AIR Application?

I'm writing a small application for myself and instead of using a database I'd like to just use Excel to store the small amount of data I have on my local file system. I want to be able to load that data without having to use the typical FileReference browse() method as it would just be annoying to do every time I use the application.
The code below seems to find the file fine as the file.exists method below and most of the other attributes seem to be correct but the file.data is always null.
I'm guessing this is a security issue and that's why I'm running into this problem but I thought I'd ask and see if there is in fact a way around this problem.
var file:File = new File(fullPath + "\\" + currentFolder + ".txt");
if(file.exists) {
var byteArray:ByteArray = file.data;
}
If you want to read the content of a file, use the following code:
var stream:FileStream = new FileStream();
stream.open("some path here", FileMode.READ);
var fileData:String = stream.readUTFBytes(stream.bytesAvailable);
trace(fileData);
The data property is inherited from FileReference class and it will be populated only after a load call (see this link).
You're close, you just need to combine that with a FileStream object
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.READ);
var str:String = fileStream.readMultiByte(file.size, File.systemCharset);
trace(str);
more info here

Sending POST variables to a browser window from AIR application

I'm building an AIR application. Basically, what I'm looking to do is using navigateToUrl() to open a browser window, assign it a "name" and then, send variables to that newly opened window using the POST method.
EDIT : I need the window to be visible, this is why I absolutely need to use the navigateToUrl() function
I already know that I CAN'T DO something like this, that the AIR application will send the variables using the GET method...
var vars:URLVariables = new URLVariables();
vars.myVar = "Hello my friend";
var req:URLRequest = new URLRequest("http://example.com/my-page.php");
req.method = "POST":
req.data = vars;
navigateToURL(req);
Considering the amount of variables I have to send (multiline texts) I absolutely need to send my variables using the POST method else Internet Explorer is truncating the query string... Works fine in Firefox and Safari but unfortunately, we will always have (hope not!) to deal with IE..
So I was thinking something like this :
import flash.net.navigateToURL;
private var _timer:Timer;
protected function loadPage():void
{
var req:URLRequest = new URLRequest("http://example.com/my-page.php");
navigateToURL(req, "myPageName");
_timer = new Timer(3000, 1);
_timer.addEventListener(TimerEvent.TIMER, postVars);
_timer.start();
}
protected function postVars(event:TimerEvent):void
{
// I'm looking to send variables using the POST method to "myPageName"
// and possibly using URLVariables()??
_timer.stop();
}
Any idea Flex coders? THANKS!
I think what you're going to need to do is open up a page you have control over, then use ExternalInterface to inject the values into a hidden form and then execute the post operation in that page form.submit(), etc.
This can happen almost instantly and it will all appear very seamless to the end user.

Flex 3 - how to support HTTP Authentication URLRequest?

I have a Flex file upload script that uses URLRequest to upload files to a server. I want to add support for http authentication (password protected directories on the server), but I don't know how to implement this - I assume I need to extend the class somehow, but on how to I'm a little lost.
I tried to modify the following (replacing HTTPService with URLRequest), but that didn't work.
private function authAndSend(service:HTTPService):void{
var encoder:Base64Encoder = new Base64Encoder();
encoder.encode("someusername:somepassword");
service.headers = {Authorization:"Basic " + encoder.toString()};
service.send();
}
I should point out that I'm not knowledgeable when it comes to ActionScript / Flex, although I have managed to successfully modify the upload script somewhat.
[Edit] - here is an update of my progress, based on the answer below, although I still cannot get this to work:
Thank you for your assistance. I've tried to implement your code but I've not had any luck.
The general behaviour I'm experiencing when dealing with HTTP authenticated locations is that with IE7 all is well but in Firefox when I attempt to upload a file to the server it displays an HTTP authentication prompt - which even if given the correct details, simply stalls the upload process.
I believe the reason IE7 is ok is down to the the session / authentication information being shared by the browser and the Flash component - however, in Firefox this is not the case and I experience the above behaviour.
Here is my updated upload function, incorporating your changes:
private function pergress():void
{
if (fileCollection.length == 0)
{
var urlString:String = "upload_process.php?folder="+folderId+"&type="+uploadType+"&feid="+formElementId+"&filetotal="+fileTotal;
if (ExternalInterface.available)
{
ExternalInterface.call("uploadComplete", urlString);
}
}
if (fileCollection.length > 0)
{
fileTotal++;
var urlRequest:URLRequest = new URLRequest("upload_file.php?folder="+folderId+"&type="+uploadType+"&feid="+formElementId+"&obfuscate="+obfuscateHash+"&sessidpass="+sessionPass);
urlRequest.method = URLRequestMethod.POST;
urlRequest.data = new URLVariables("name=Bryn+Jones");
var encoder:Base64Encoder = new Base64Encoder();
encoder.encode("testuser:testpass");
var credsHeader:URLRequestHeader = new URLRequestHeader("Authorization", "Basic " + encoder.toString());
urlRequest.requestHeaders.push(credsHeader);
file = FileReference(fileCollection.getItemAt(0));
file.addEventListener(Event.COMPLETE, completeHandler);
file.addEventListener(HTTPStatusEvent.HTTP_STATUS, onHTTPStatus);
file.addEventListener(ProgressEvent.PROGRESS, onUploadProgress);
file.upload(urlRequest);
}
}
As stated above, I seem to be experiencing the same results with or without the amendments to my function.
Can I ask also where the crossdomain.xml should be located - as I do not currently have one and am unsure where to place it.
The syntax is a little different for URLRequest, but the idea's the same:
private function doWork():void
{
var req:URLRequest = new URLRequest("http://yoursite.com/yourservice.ext");
req.method = URLRequestMethod.POST;
req.data = new URLVariables("name=John+Doe");
var encoder:Base64Encoder = new Base64Encoder();
encoder.encode("yourusername:yourpassword");
var credsHeader:URLRequestHeader = new URLRequestHeader("Authorization", "Basic " + encoder.toString());
req.requestHeaders.push(credsHeader);
var loader:URLLoader = new URLLoader();
loader.load(req);
}
A couple of things to keep in mind:
Best I can tell, for some reason, this only works where request method is POST; the headers don't get set with GET requests.
Interestingly, it also fails unless at least one URLVariables name-value pair gets packaged with the request, as indicated above. That's why many of the examples you see out there (including mine) attach "name=John+Doe" -- it's just a placeholder for some data that URLRequest seems to require when setting any custom HTTP headers. Without it, even a properly authenticated POST request will also fail.
Apparently, Flash player version 9.0.115.0 completely blocks all Authorization headers (more information on this one here), so you'll probably want to keep that in mind, too.
You'll almost surely have to modify your crossdomain.xml file to accommodate the header(s) you're going to be sending. In my case, I'm using this, which is a rather wide-open policy file in that it accepts from any domain, so in your case, you might want to limit things a bit more, depending on how security-conscious you are.
crossdomain.xml:
<?xml version="1.0"?>
<cross-domain-policy>
<allow-access-from domain="*" />
<allow-http-request-headers-from domain="*" headers="Authorization" />
</cross-domain-policy>
... and that seems to work; more information on this one is available from Adobe here).
The code above was tested with Flash player 10 (with debug & release SWFs), so it should work for you, but I wanted to update my original post to include all this extra info in case you run into any issues, as the chances seem (sadly) likely that you will.
Hope it helps! Good luck. I'll keep an eye out for comments.
The FileReference.upload() and FileReference.download() methods do not support the URLRequest.requestHeaders parameter.
http://livedocs.adobe.com/flex/2/langref/flash/net/URLRequest.html
If you want to upload a file, you just need to send the correct headers and the content of file using URLRequest via UploadPostHelper class. This works 100%, i am using this class to upload generated images and CSV files, but you could upload any kind of file.
This class simply prepares the request with headers and content as if you would be uploading the file from a html form.
http://code.google.com/p/as3asclublib/source/browse/trunk/net/UploadPostHelper.as?r=118
_urlRequest = new URLRequest(url);
_urlRequest.data = "LoG";
_urlRequest.method = URLRequestMethod.POST;
_urlRequest.requestHeaders.push(new URLRequestHeader("X-HTTP-Code-Override", "true"));
_urlRequest.requestHeaders.push(new URLRequestHeader("pragma", "no-cache"));
initCredentials();
_loader.dataFormat = URLLoaderDataFormat.BINARY;
//this creates a security problem, putting the content type in the headers bypasses this problem
//_urlRequest.contentType = 'multipart/form-data; boundary=' + UploadPostHelper.getBoundary();
_urlRequest.requestHeaders.push( new URLRequestHeader( 'Cache-Control', 'no-cache' ) );
_urlRequest.requestHeaders.push(new URLRequestHeader('Content-Type', 'multipart/form-data; boundary=' + UploadPostHelper.getBoundary()));
_urlRequest.data = UploadPostHelper.getPostData("file.csv", param[1]);
_loader.load(_urlRequest);
I'm not sure about this but have you tried adding username:password# to the beginning of your url?
"http://username:password#yoursite.com/yourservice.ext"
var service : HTTPService = new HTTPService ();
var encoder:Base64Encoder = new Base64Encoder();
encoder.insertNewLines = false;
encoder.encode("user:password");
service.headers = {Authorization:"Basic " + encoder.toString()};
service.method = HTTPRequestMessage.POST_METHOD;
service.request = new URLVariables("name=John+Doe");
service.addEventListener(FaultEvent.FAULT,error_handler );
service.addEventListener(ResultEvent.RESULT,result_handler);
service.url = 'http://blah.blah.xml?'+UIDUtil.createUID();
service.send();
Seemingly similar problem was solved here. I urge you to also check the Flexcoders post linked to in the first post.
The problem was that FireFox uses a separate browser window instance to send the file upload request. The solution is to manually attach the session id to the request url. The session id is not attached as a regular GET variable, but with a semicolon (the reason for this syntax is unknown to me).
Flash is very limited in terms of what sort of headers you can pass with an http request (and it changes between browsers and OSes). If you get this to work on one browser/OS, make sure you test it on the others.
The best thing to do is not mess with HTTP headers.
We have the same issue (uploading to Picasa Web Albums from flash) and post through a proxy on our server. We pass the extra headers through as post parameters and our proxy does the right thing.
"http://username:password#yoursite.com/yourservice.ext"
This doesn't work in IE (http://www.theregister.co.uk/2004/01/30/ms_drop_authentication_technique/) and doesn't seem to work in Chrome either.
probably not usable in Flash
Here is a work-around when using ASP.Net based in part on the work here.
I built a component that dynamically writes Flex objects to the page so they can be used in UpdatePanels. Message me if you want they code. To solve the above problem in pages where authentication cookies will need to be sent by URLRequest, I add the values in as flashVars.
This code only works in my object, but you get the idea
Dictionary<string, string> flashVars = new Dictionary<string, string>();
flashVars.Add("auth", Request.Cookies["LOOKINGGLASSFORMSAUTH"].Value);
flashVars.Add("sess", Request.Cookies["ASP.NET_SessionId"].Value);
myFlexObject.SetFlashVars(flashVars);
Then in the Flex Object, check for the params
if (Application.application.parameters.sess != null)
sendVars.sess= Application.application.parameters.sess;
if (Application.application.parameters.auth != null)
sendVars.au= Application.application.parameters.auth;
request.data = sendVars;
request.url = url;
request.method = URLRequestMethod.POST;
Finally stuff the cookies in on global.asax BeginRequest
if (Request.RequestType=="POST" && Request.Path.EndsWith("upload.aspx"))
{
try
{
string session_param_name = "sess";
string session_cookie_name = "ASP.NET_SESSIONID";
string session_value = Request.Form[session_param_name]; // ?? Request.QueryString[session_param_name];
if (session_value != null) { UpdateCookie(session_cookie_name, session_value); }
}
catch (Exception) { }
try
{
string auth_param_name = "au";
string auth_cookie_name = FormsAuthentication.FormsCookieName;
string auth_value = Request.Form[auth_param_name];// ?? Request.QueryString[auth_param_name];
if (auth_value != null) { UpdateCookie(auth_cookie_name, auth_value); }
}
catch (Exception) { }
}
Hope this help someone avoid the 6 hours I just spent addressing this. Adobe has closed the issue as unresolvable, so this was my last resort.

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