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SWFUpload and Dynamic POST

Wyatt •

Recently, it came across the need to generate the upload_script string dynamically. This can be useful if you are trying to pass additional arguement along with the file such as a caption that is different for each file. I figured I’d drop it here so maybe someone else who is in the same boat doesn’t have to have such a hard learning curve :-)

First, we define a callback function that dynamically generates our upload string:

function generateUploadString (file) {
        var basestring = ‘/rem/upload/uploadFile?’
        var cookie = readCookie(‘JSESSIONID’);
        var caption = ‘&caption=’ + document.getElementById(file.id+‘caption’).value;
        return dwrString+cookie+caption;
}

I should note when I generated my file_queue lines that i added an input field with the file.id+caption as its identifier. Next, we need to edit the SWFUpload-src.js file and add a field to tell if the upload_script variable is function or a string

…….
        this.addSetting("flash_target", settings["flash_target"], "");                                                                                                                  // Where to output the flash (not used)
        this.addSetting("flash_width", settings["flash_width"], "1px");                                                                                                                 // Flash width
        this.addSetting("flash_height", settings["flash_height"], "1px");                                                                                                                       // Flash height
        this.addSetting("flash_color", settings["flash_color"], "#000000");                                                                                                             // Flash color</p>

        //dynamic generation of upload_script variable
        this.addSetting(‘upload_script_is_function’, settings[‘upload_script_is_function’], );

       …..
        sb.append("&uploadQueueCompleteCallback=" + this.getSetting("upload_queue_complete_callback"));
        sb.append("&autoUpload=" + this.getSetting("auto_upload"));
        sb.append("&allowedFiletypes=" + this.getSetting("allowed_filetypes"));
        sb.append("&maximumFilesize=" + this.getSetting("allowed_filesize"));
        sb.append("&uploadScriptIsFunction=" + this.getSetting(‘upload_script_is_function’));
        …..</div> </div>

Now we need to actually modifiy the SWFUpload action script and add the uploadScriptIsFunction variable:

…..
                uploadQueueCompleteCallback = _root.uploadQueueCompleteCallback;
                flashLoadedCallback = _root.flashLoadedCallback;
                uploadFileStartCallback = _root.uploadFileStartCallback;
                uploadScriptIsFunction = _root.uploadScriptIsFunction;
                ……

And our modification to the upload() function:

// Start upload
                        if(uploadScriptIsFunction) {
                                //user says this is dynamically generated
                                currentFile.upload(String(ExternalInterface.call(uploadScript, getFileObject(currentFileId, currentFile))));
                        } else {
                                //statically specified
                                currentFile.upload(uploadScript);
                        }

Now when you create your SWFUpload object in Javascript, just specify it like such to take advantage of the new feature:

swfu = new SWFUpload({
                                upload_script: ‘generateUploadString’,
                                upload_script_is_function: true,
                                …….

Oh yeah, and we have to rebuild the flash app to, so for me that’s:

mtasc classes/com/mammon/swfupload/*.as -swf SWFUpload.swf -version 8 -main -v -header 1:1:12:FFFFFF

Hope it helps someone.

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