re-upload possible?

3 posts, 0 answers
  1. Tayger
    Tayger avatar
    191 posts
    Member since:
    Jan 2015

    Posted 02 Mar 2018 Link to this post

    Hello there

    Just got the message that some of you have holidays. Wish all those guys a good time. You are all doing a great job at Telerik!

    My question: I'm using the kendoUpload widget that is working well. I'm trying to keep customers logged in if they have set that in their settings. So when the session ran out (after a certain time of user nactivity) I'm checking every server side action. If the session ran out I recreate it and send the user action again from client (now with reactivated session). That works everywhere well and the user won't realise what just happened. There is only one case I don't know how to treat the same way: kendoUpload

    When the user is doing a file upload (single file mode) and there is no more serverside  session I call the upload function again but then there are no (to be uploaded) image information anymore. After thinking about this behaviour is obvious to me since I'm calling the function programmatically there are no values set  anymore.

    So I wonder if it's possible to do the upload programmatically inside the upload widget (or to catch the upload data) to do the upload again? I'm using the success event  of the KendoUpload widget to get/check the upload status from the server:

    a) Session still active, upload worked well

    b) Session timeout, restart the upload again (programmatically)

    It's not a big thing if there is no solution for that problem. So I'm asking if there is a way I could do the upload again (programmatically) with the data/file the user initially tried to upload?


  2. Ianko
    Ianko avatar
    1956 posts

    Posted 06 Mar 2018 Link to this post

    Hello Tayger,

    Typically, with upload input, there is no possible way to add a stream value so that it appears as a file is selected. This is an user interaction field and as it serves the purpose of uploading a file from the client to the server, there is no programmatic access to the interact with the stream added by the user. Or create a new one even if previously the user has added. Generally, there are security reasons for that to be not doable. 

    If you are using the async option, however, you can fake it up. You can interact with the files collection of the Upload so that after session timeout the Upload appears as if the file is uploaded successfully.

    If you are using the classic mode of the Kendo Upload what I can suggest you is to implement some additional UI element to show to the client that the file is uploaded succesfully and hide the Kendo Upload widget. 

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  3. Tayger
    Tayger avatar
    191 posts
    Member since:
    Jan 2015

    Posted 15 Mar 2018 in reply to Ianko Link to this post

    Hello Ianko

    Thank you for your answer. I thought that there is no easy/obvious question. I also really get your point how to fake it. But while reading your answer another idea came up to me. I've tried that out and it works: I check for existing session in the upload event like this:

                async: {
                    saveUrl: "../php/uploadimage.php"
                upload: function (e) {
                    // Make sure session is active
                        type: 'POST',
                        url: '../php/sessionrefresh.php',
                        dataType: 'json',
                        async: false,
                        success: function(s) {
                            if (s.state !== 'OK') {
                                window.location.href = 'https://.../sessionend.php';


    In the upload event of the upload widget the sessionrefresh.php function tries to reactivate the session (if not still active) and returns OK if session is still active or could be reactivated. In this case proceed with the image upload. If the session couldn't be reactivated it heads to sessionend.php telling the user he is logged out.

    I don't know if this is the best solution to solve this problem but it works!



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