Session is different if flash uploads photo to the aspx page - asp.net

I have a aspx called user-photo-upload.aspx and another aspx called get-photo.aspx. I set the Session["PhotoId"] in the page_load method of user-photo-upload.aspx.
If I visit the user-photo-upload.aspx through the browser normally, the session can be retrieved in get-photo.aspx.
But if the flash uploads photo to the user-photo-upload.aspx page, I can't get the Session["PhotoId"] in get-photo.aspx.
I discover that the Session ID is different when visiting the page using browser normally or by flash. I don't know why flash uses another session.
What should I do?

The Flash plugin acts as a separate client, so both the browser and the plugin receiving individual session IDs is the expected behavior.
You will have to work around this by setting the original session ID as a variable in the Flash movie, either as a FlashVar or via JavaScript, then sending it as a GET parameter to the server along with the first request issued, and replacing the new ID created for the Flash client with the one that was given to the server.
This question relates to the same problem in Java, perhaps it can help you to solve your problem.

We had the same problem with a Flash Uploader. This is how we solved it...
(1) We added a new parameter session_id to the client side init code of the Flash Uploader:
<script type="text/javascript">
var swfu<%=RandomId %>;
$(document).ready(function() {
swfu<%=RandomId %> = new SWFUpload({
// Backend Settings
upload_url: "./picupload.aspx",
post_params : {
"PictureCategory" : "<%= EncryptedPictureCategory() %>",
"picture_id": "<%= EncryptedPictureId() %>",
"session_id": "<%= HttpContext.Current.Session.SessionID %>"
},
// *snip* ...
</script>
(2) We altered our Session_Start method in Global.asax.cs to accept Session IDs from the request:
protected void Session_Start(Object sender, EventArgs e)
{
if (Request["session_id"] != null)
{
bool isRedirected, isCookieAdded;
string oldSessionId = Request["session_id"];
SessionIDManager manager = new SessionIDManager();
manager.RemoveSessionID(HttpContext.Current);
manager.SaveSessionID(HttpContext.Current, oldSessionId, out isRedirected, out isCookieAdded);
}
else
{
Response.Redirect(LoginPagePath);
}
}

Related

AjaxFileUpload: How can I alert the user to a server-side error in OnUploadComplete?

I've got the AjaxFileUpload control working just fine -- it uploads, and on completion calls the server-side code to move the files around, works just fine, etc etc etc.
What I'm worried about are potential server-side errors, and how to hand back some sort of warning to the user. Not an Ajax error, but something on the server-side code.
Now, I've got log4net running just fine, and it's called in my error-trapping code and merrily dumping logs when I hard-code an error.
But that doesn't tell the users anything.
RegisterStartupScript doesn't seem to be a valid solution, because there's no PostBack that would allow it to operate (same as my first attempt at populating fields. doh!).
Now, I can shove some JS into the ClientUploadComplete or ClientUploadCompleteAll to do a PostBack... but that doesn't seem right, and it would require that server-side error-messages be queued-up for display. Plus, it clears out the AjaxFileUpload display of what has been uploaded.
All the error-handling I've seen regarding these controls is for Ajax errors.
Is there anything for server-side issues that allows for easy feedback to the user?
Am I even barking up the right trees?
UPDATE Using the pointers # Yuriy's other answer I've got the following working:
Onn the server side:
protected void OnUploadComplete(object sender, AjaxFileUploadEventArgs e)
{
try
{
// does something with the uploaded files that _might_ fail
}
catch (Exception ex)
{
var ce = Logger.LogError(ex);
var msg = string.Format("{{ 'id': '{0}', 'message': '{1}'}}",
ce.ErrorId, ce.Message);
e.PostedUrl = msg;
}
}
(The Logger dumps the complete exception into a log4net log, and returns an error-number and consumer-friendly message to contact support)
Back on the page, the AjaxFileUpload control is configured to call the JS when complete:
<asp:AjaxFileUpload runat="server" ID="Uploader" MaximumNumberOfFiles="10"
OnUploadComplete="OnUploadComplete"
OnClientUploadComplete="AjaxFileUpload1_OnClientUploadComplete"/>
And the javascript:
<script type="text/javascript">
function AjaxFileUpload1_OnClientUploadComplete(sender, args) {
var errText = args.get_postedUrl();
if (!errText) return; // only process if populated
var errinfo = Sys.Serialization.JavaScriptSerializer.deserialize(errText);
if (errinfo && errinfo.id && errinfo.message) {
var idEl = document.getElementById('errnbr');
var msgEl = document.getElementById('errmsg');
if (idEl && msgEl) {
idEl.innerHTML = errinfo.id;
msgEl.innerHTML = errinfo.message;
}
}
}
</script>
which populates the following:
<div class="failureNotification" id="ErrorDisplay" runat="server">
<span id="errnbr"><asp:Literal ID="ErrorNumber" runat="server"></asp:Literal></span>
<span id="errmsg"><asp:Literal ID="FailureText" runat="server"></asp:Literal></span>
</div>
Although AjaxFileUploadState enumeration include Failed member I can't find any case where it used.
So there are two solutions available I believe.
The first is to tweak ACT project to add setters to State and StatusMessage properties of AjaxFileUploadEventArgs class and handle values of these properties on client in raiseUploadComplete function of Sys.Extended.UI.AjaxFileUpload.Control class and onUploadCompleteHandler of Sys.Extended.UI.AjaxFileUpload.ProcessorHtml5 class.
Or you can pass custom JSON to client via AjaxFileUploadEventArgs.PostedUrl property, deserialize it on client in OnClientUploadComplete handler and show error message if any. Please check this question for sample of usage PostedUrl property: getting asynfileupload controls file name on button click

Response.Redirect(Request.Url.AbsoluteUri) doesn't update page data

I have Page_load method like this:
private void Page_Load(object sender, System.EventArgs e)
{
if (!IsPostBack)
{
// Load Content
LoadContent();
return;
}
// some code here
}
And I use Response.Redirect(Request.Url.AbsoluteUri) at the end of methods to prevent re-post actions cased by page refrashing. When I run my app from source code that works well (debug or run mode), but when I publish the app (even on the same machine) page data (which loads on LoadContent) is not updated on updated page (but re-post actions is prevented).
Please, could anyone tell me why it happens?
ADDED:
There is LoadContent() method:
// firstly I get an supervisedGroups list TIBCO iProcess Engine via .NET vendor library, and then:
if (supervisedGroups != null)
{
rptSupervisedGroups.DataSource = supervisedGroups; // rpt.. is Repeater
rptSupervisedGroups.DataBind();
}
ADDED:
Method where Response.Redirect are used:
private void removeFromGroup(string strGroupName)
{
using(SqlConnection con = DBHelper.GetNewConnection())
{
con.Open();
// here comes query to DB
}
// Reload Page
Response.Redirect(Request.Url.AbsoluteUri);
}
You have two ways to solve this cache issue.
One is to give instructions to the browser to not cache this page, for example on page load you run:
Response.Cache.SetExpires(DateTime.UtcNow.AddYears(-4));
Response.Cache.SetValidUntilExpires(false);
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches);
Response.Cache.SetNoStore();
But a better solution is to add a random number at the end of the url when you make the redirect, or even better add the new id from the data that you have insert, eg:
Response.Redirect("samepage.aspx?newid=" + NewId);
that way the page will forced to be readed again, and you still have the cache functionality.
Most likely your page is cached. Try to hit shift-f5 to check the content. You can make all redirect urls unique to prevent the browser showing a cached page. Or disable caching for the specific page.

ASP.NET Facebook app session issue with safari

Currently I am working on a Facebook app and it's developed by using ASP.NET.
This app works fine with IE(7,8 and 9) FF and Chrome.
The first page is default.aspx and it will handle the authentication then redirect to home.aspx
Now the only issue it has is that Safari doesn't accept cross-domain cookies. I've changed the web.config file and add it in order to avoid the use of cookies.
After that, the URL comes to
http://www.testdomain.com/(S(gvsc2i45pqvzqm3lv2xoe4zm))/default.aspx
It just can't be redirect from default.aspx to home.aspx automatically...
Anyone got a clue?
Or, is there anyway that i can deal with Safari with ASP.Net session in Facebook app?
Tons of thanks
PS. The code from default.aspx page
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (!string.IsNullOrEmpty(Request.Params["signed_request"]))
{
string signed_request = Request.Params["signed_request"];
if (!string.IsNullOrEmpty(signed_request))
{
// split signed request into encoded signature and payload
string[] signedRequestParts = signed_request.Split('.');
string encodedSignature = signedRequestParts[0];
string payload = signedRequestParts[1];
// decode signature
string signature = decodeSignature(encodedSignature);
// calculate signature from payload
string expectedSignature = hash_hmac(payload, Facebook.FacebookApplication.Current.AppSecret);
if (signature == expectedSignature)
{
// signature was not modified
Dictionary<string, string> parameters = DecodePayload(payload);
if (parameters != null)
{
string UserId = parameters["user_id"];
Session.Add("UserId", _SystemUser.SystemUserId);
Session.Add("Username", _SystemUser.Username);
Response.Redirect("Home.aspx?user_id=" + UserId);
}
}
}
}
if (!String.IsNullOrEmpty(Request["error_reason"])) // user denied your request to login
{
logger.Debug("Error Reason: " + Request["error_reason"]);
//User denied access
}
if (String.IsNullOrEmpty(Request["code"])) // request to login
{
string url1 = String.Format("https://www.facebook.com/dialog/oauth?client_id={0}&redirect_uri={1}&scope={2}", Facebook.FacebookApplication.Current.AppId, callbackUrl, ext_perms);
Response.Redirect(url1);
}
}
}
When using cookieless sessions, ASP.Net will automatically redirect any requests without a session ID in the URL to the same page, but with a new SessionID in the URL. However, it redirects as a GET request, and thus does not forward on any POSTED parameters ... so after the redirect your "parameters" variable, from the decoded signed_request, will be missing because the page will no longer have the signed_request POSTed parameter.
There are two possible solutions to this (that I know of):
Intercept the initial redirect in Global.ascx, and instead do your own redirect with the new SessionID in the URL ... BUT, do this as a self-posting form in Javascript where the form also has a signed_request param with the value of the signed_request.
Turn cookie sessions back on, and in your first page redirect out of FB to a page. In this page set a Session variable (which will get ASP.Net to set a session cookie), and then redirect back into FB.
You may/will also need some code to handle any app_data, if this is on a tab page too.
Sorry I can't be more useful code wise. I've written my own handlers for my job, but my workplace now owns that code! I'm never sure how much is OK to share.
I used cookieless session, but as the initial page was getting refreshed, the Facebook "signed_request" POSTed to the landing page was lost.
As a workaround, I added an HTTPModule to override EndRequest() event. In the event if the page is "initial page" & contained "signed_request" POSTed, the value is added as querystring. In the page we would check the querystring value and set it into session, to be used in the application.
The EndRequest is as below:
void context_EndRequest(object sender, EventArgs e)
{
HttpContext cntxt = HttpContext.Current;
const string paramname = "signed_request";
const string initialPage= "/startapp.aspx";
if ((String.Compare(cntxt.Request.Url.AbsolutePath, initialPage, true) == 0) && (!String.IsNullOrEmpty(cntxt.Request[paramname])))
{
string strQuerySignedReq = paramname+"=" + cntxt.Request[paramname];
if (cntxt.Response.RedirectLocation.Contains(".aspx?"))
cntxt.Response.RedirectLocation = cntxt.Response.RedirectLocation + "&" + strQuerySignedReq;
else
cntxt.Response.RedirectLocation = cntxt.Response.RedirectLocation + "?" + strQuerySignedReq;
}
}
The initial page - "startapp.aspx", load event would be:
protected void Page_Load(object sender, EventArgs e)
{
signed_request = Request.QueryString["signed_request"];
}
The disadvantage of the code is that EndRequest() would execute for all requests. Also, only relative url should be used for links. I have had several annoying experiences on cookies and Facebook, due to various security levels on different browsers. Hence, I can live with the disadvantages. Hope this helps!
I know this is an old question, but I had exactly the same problem and found a solution.
The solution here works if you're using a SQL Server in your application.
Using cookieless to store your SessionId in the URL will avoid the cookie problem, but still missing the Session issue in Safari.
Well, you'll need to set a SQL SessionState, this will make your application communicate with your Database to store the Sessions. This will work for facebook canvas apps in Safari.
Setting this is simple:
Registering: run aspnet_regsql.exe (in C:/Windows/Microsoft.NET/Framework/'Framework version'/)
Check parameters in https://msdn.microsoft.com/en-us/library/ms229862.aspx (the main ones are -S –ssadd)
In the same path, there is a InstallSqlState.SQL script. Run it on your Database Server.
Now, set this tag in your Web.Config file:
<configuration>
<system.web>
<sessionState mode="StateServer" stateConnectionString="tcpip=127.0.0.1:42424" timeout="120" cookieless="true" />
</system.web>
</configuration>
And the magic is done!
There is something to remember. You can't do WebRequests to facebook from Server side to request for access tokens, because facebook redirects the calls to the "Valid OAuth redirect URIs", and completely ignores the SessionId parameters in the Request URI. You still can make WebRequests to APIs, but the authentication will need to be assyncronous, using Javascript.

jQuery UI autocomplete is not displaying results fetched via AJAX

I am trying to use the jQuery UI autocomplete feature in my web application. What I have set up is a page called SearchPreload.aspx. This page checks for a value (term) to come in along with another parameter. The page validates the values that are incoming, and then it pulls some data from the database and prints out a javascript array (ex: ["item1","item2"]) on the page. Code:
protected void Page_Load(object sender, EventArgs e)
{
string curVal;
string type ="";
if (Request.QueryString["term"] != null)
{
curVal = Request.QueryString["term"].ToString();
curVal = curVal.ToLower();
if (Request.QueryString["Type"] != null)
type = Request.QueryString["Type"].ToString();
SwitchType(type,curVal);
}
}
public string PreLoadStrings(List<string> PreLoadValues, string curVal)
{
StringBuilder sb = new StringBuilder();
if (PreLoadValues.Any())
{
sb.Append("[\"");
foreach (string str in PreLoadValues)
{
if (!string.IsNullOrEmpty(str))
{
if (str.ToLower().Contains(curVal))
sb.Append(str).Append("\",\"");
}
}
sb.Append("\"];");
Response.Write(sb.ToString());
return sb.ToString();
}
}
The db part is working fine and printing out the correct data on the screen of the page if I navigate to it via browser.
The jQuery ui autocomplete is written as follows:
$(".searchBox").autocomplete({
source: "SearchPreload.aspx?Type=rbChoice",
minLength: 1
});
Now if my understanding is correct, every time I type in the search box, it should act as a keypress and fire my source to limit the data correct? When I through a debug statement in SearchPreload.aspx code behind, it appears that the page is not being hit at all.
If I wrap the autocomplete function in a .keypress function, then I get into the search preload page but still I do not get any results. I just want to show the results under the search box just like the default functionality example on the jQuery website. What am I doing wrong?
autocomplete will NOT display suggestions if the JSON returned by the server is invalid. So copy the following URL (or the returned JSON data) and paste it on JSONLint. See if your JSON is valid.
http://yourwebsite.com/path/to/Searchpreload.aspx?Type=rbChoice&term=Something
PS: I do not see that you're calling the PreLoadStrings function. I hope this is normal.
A couple of things to check.
Make sure that the path to the page is correct. If you are at http://mysite.com/subfolder/PageWithAutoComplete.aspx, and your searchpreload.aspx page is in another directory such as http://mysite.com/anotherFolder/searchpreload.aspx the url that you are using as the source would be incorrect, it would need to be
source: "/anotherFolder/Searchpreload.aspx?Type=rbChoice"
One other thing that you could try is to make the method that you are calling a page method on the searchpreload.aspx page. Typically when working with javascript, I try to use page methods to handle ajax reqeusts and send back it's data. More on page methods can be found here: http://www.singingeels.com/Articles/Using_Page_Methods_in_ASPNET_AJAX.aspx
HTH.

How to open new window with streamed document in ASP.NET Web Forms

I have an ASP.NET Web Forms application. I want to have a button to post back to the server that will use my fields on my form (after validation) as parameters to a server process that will generate a document and stream it back to the browser. I want the form to be updated with some status results.
What is the best way to achieve this? Right now, I've got the button click generating the document and streaming it back to the browser (it's a Word document and the dialog pops up, and the Word document can be opened successfully) but the page doesn't get updated.
I have jQuery in my solution, so using js isn't an issue if that is required.
I have a very similar process on one of my servers, and the way I've handled it is to create a temporary document on the server rather than doing a live stream. It requires a bit of housekeeping code to tidy it up, but it does mean that you can return the results of the generation and then do a client-side redirect to the generated document if successful. In my case, I'm using jQuery and AJAX to do the document generation and page update, but the same principle should also apply to a pure WebForms approach.
This was way more difficult to do than I thought. The main issue is with opening a new browser window for a Word document. The window briefly flashes up, then closes - no Word document appears. It seems to be a security issue.
If i click a button on my page, I can stream the Word doc back as the response, and the browser dialog pops up allowing me to Open/Save/Cancel, but of course, my page doesn't refresh.
My final solution to this was to use a client script on the button click to temporarily set the form's target to _blank. This forces the response to the click on the postback to go to a new browser window (which automatically closes after the download dialog is dismissed):
<asp:Button Text="Generate Doc" runat="server" ID="btnGenerateDoc"
onclick="btnGenerateDoc_Click" OnClientClick="SetupPageRefresh()" />
My SetupPageRefresh function is as follows:
function SetupPageRefresh() {
// Force the button to open a new browser window.
form1.target = '_blank';
// Immediately reset the form's target back to this page, and setup a poll
// to the server to wait until the document has been generated.
setTimeout("OnTimeout();", 1);
}
Then my OnTimeout function resets the target for the form, then starts polling a web service to wait until the server process is complete. (I have a counter in my Session that I update once the process has completed.)
function OnTimeout() {
// Reset the form's target back to this page (from _blank).
form1.target = '_self';
// Poll for a change.
Poll();
}
And the Poll function simply uses jQuery's ajax function to poll my web service:
function Poll() {
var currentCount = $("#hidCount").val();
$.ajax({
url: "/WebService1.asmx/CheckCount",
data: JSON.stringify({ currentCount: currentCount }),
success: function (data) {
var changed = data.d;
if (changed) {
// Change recorded, so refresh the page.
window.location = window.location;
}
else {
// No change - check again in 1 second.
setTimeout("Poll();", 1000);
}
}
});
}
So this does a 1 second poll to my web service waiting for the Session's counter to change from the value in the hidden field on the page. This means it doesn't matter how long the server process takes to generate the Word document (and update the database, etc.) the page won't refresh until it's done.
When the web service call comes back with true, the page is refreshed with the window.location = window.location statement.
For completeness, my Web Service looks like this:
/// <summary>
/// Summary description for WebService1
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
[System.Web.Script.Services.ScriptService]
public class WebService1 : WebService
{
[WebMethod(EnableSession=true)]
public bool CheckCount(int currentCount)
{
if (Session["Count"] == null)
Session["Count"] = 0;
var count = (int)Session["Count"];
var changed = count != currentCount;
return changed;
}
}
Hopefully that helps somebody else!

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