Using the FileReference class

Flash Player 9 and later, Adobe AIR 1.0 and later

A FileReference object represents a data file on a client or server machine. The methods of the FileReference class let your application load and save data files locally, and transfer file data to and from remote servers.

The FileReference class offers two different approaches to loading, transferring, and saving data files. Since its introduction, the FileReference class has includedthe browse() method, the upload() method, and the download() method. Use the browse() method to let the user select a file. Use the upload() method to transfer the file data to a remote server. Use the download() method to retrieve that data from the server and save it in a local file. Starting with Flash Player 10 and Adobe AIR 1.5, the FileReference class includes the load() and save() methods. The load() and save() methods allow you to access and save local files directly as well. The use of those methods is similar to the equivalent-named methods in the URLLoader and Loader classes.

Note: The File class, which extends the FileReference class, and the FileStream class provide additional functions for working with files and the local file system. The File and FileStream classes are only supported in AIR and not in the Flash Player.

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FileReference class

Each FileReference object represents a single data file on the local machine. The properties of the FileReference class contain information about the file’s size, type, name, filename extension, creator, creation date, and modification date.

Note: The creator property is supported on Mac OS only. All other platforms return null.
Note: The extension property is only supported in Adobe AIR.

You can create an instance of the FileReference class one of two ways:

  • Use the new operator, as shown in the following code:
    import flash.net.FileReference; 
    var fileRef:FileReference = new FileReference();
  • Call the FileReferenceList.browse() method, which opens a dialog box and prompts the user to select one or more files to upload. It then creates an array of FileReference objects if the user successfully selects one or more files.

Once you have created a FileReference object, you can do the following:

  • Call the FileReference.browse() method, which opens a dialog box and prompts the user to select a single file from the local file system. This is usually done before a subsequent call to the FileReference.upload() method or FileReference.load() method. Call the FileReference.upload() method to upload the file to a remote server. Call to the FileReference.load() method to open a local file.

  • Call the FileReference.download() method. The download() method opens a dialog box to let the user select a location for saving a new file. Then it downloads data from the server and stores it in the new file.

  • Call the FileReference.load() method. This method begins loading data from a file selected previously using the browse() method. The load() method can’t be called until the browse() operation completes (the user selects a file).

  • Call the FileReference.save() method. This method opens a dialog box and prompts the user to choose a single file location on the local file system. It then saves data to the specified location.

Note: You can only perform one browse(), download(), or save() action at a time, because only one dialog box can be open at any point.

The FileReference object properties such as name, size, or modificationDate are not defined until one of the following happens:

  • The FileReference.browse() method or FileReferenceList.browse() method has been called, and the user has selected a file using the dialog box.

  • The FileReference.download() method has been called, and the user has specified a new file location using the dialog box.

Note: When performing a download, only the FileReference.name property is populated before the download is complete. After the file has been downloaded, all properties are available.

While calls to the FileReference.browse(), FileReferenceList.browse(), FileReference.download(), FileReference.load(), or FileReference.save() methods are executing, most players continue SWF file playback including dispatching events and executing code.

For uploading and downloading operations, a SWF file can access files only within its own domain, including any domains specified by a policy file. You need to put a policy file on the server containing the file if that server is not in the same domain as the SWF file initiating the upload or download.

See FileReference.

Loading data from files

The FileReference.load() method lets you load data from a local file into memory.

Note: Your code must first call the FileReference.browse() method to let the user select a file to load. This restriction does not apply to content running in Adobe AIR in the application security sandbox

The FileReference.load() method returns immediately after being called, but the data being loaded isn’t available immediately. The FileReference object dispatches events to invoke listener methods at each step of the loading process.

The FileReference object dispatches the following events during the loading process.

  • open event (Event.OPEN): Dispatched when the load operation starts.

  • progress event (ProgressEvent.PROGRESS): Dispatched periodically as bytes of data are read from the file.

  • complete event (Event.COMPLETE): Dispatched when the load operation completes successfully.

  • ioError event (IOErrorEvent.IO_ERROR): Dispatched if the load process fails because an input/output error occurs while opening or reading data from the file.

Once the FileReference object dispatches the complete event, the loaded data can be accessed as a ByteArray in the FileReference object’s data property.

The following example shows how to prompt the user to select a file and then load the data from that file into memory:

package 
{ 
     import flash.display.Sprite; 
    import flash.events.*;  
    import flash.net.FileFilter; 
    import flash.net.FileReference; 
    import flash.net.URLRequest; 
    import flash.utils.ByteArray; 
 
    public class FileReferenceExample1 extends Sprite 
    { 
        private var fileRef:FileReference; 
        public function FileReferenceExample1() 
        { 
            fileRef = new FileReference(); 
            fileRef.addEventListener(Event.SELECT, onFileSelected); 
            fileRef.addEventListener(Event.CANCEL, onCancel); 
            fileRef.addEventListener(IOErrorEvent.IO_ERROR, onIOError); 
            fileRef.addEventListener(SecurityErrorEvent.SECURITY_ERROR, 
                        onSecurityError); 
            var textTypeFilter:FileFilter = new FileFilter("Text Files (*.txt, *.rtf)", 
                        "*.txt;*.rtf"); 
            fileRef.browse([textTypeFilter]); 
        } 
        public function onFileSelected(evt:Event):void 
        { 
            fileRef.addEventListener(ProgressEvent.PROGRESS, onProgress); 
            fileRef.addEventListener(Event.COMPLETE, onComplete); 
            fileRef.load(); 
        } 
 
        public function onProgress(evt:ProgressEvent):void 
        { 
            trace("Loaded " + evt.bytesLoaded + " of " + evt.bytesTotal + " bytes."); 
        } 
 
        public function onComplete(evt:Event):void 
        { 
            trace("File was successfully loaded."); 
            trace(fileRef.data); 
        } 
 
        public function onCancel(evt:Event):void 
        { 
            trace("The browse request was canceled by the user."); 
        } 
 
        public function onIOError(evt:IOErrorEvent):void 
        { 
            trace("There was an IO Error."); 
        } 
        public function onSecurityError(evt:Event):void 
        { 
            trace("There was a security error."); 
        } 
    } 
}

The example code first creates the FileReference object named fileRef and then calls its browse() method. The browse() method opens a dialog box that prompts the user to select a file. When a file is selected, the code invokes the onFileSelected() method. This method adds listeners for the progress and complete events and then calls the FileReference object’s load() method. The other handler methods in the example simply output messages to report on the progress of the load operation. When the loading completes, the application displays the contents of the loaded file using the trace() method.

In Adobe AIR, the FileStream class provides additional functionality for reading data from a local file. See Reading and writing files.

Saving data to local files

The FileReference.save() method lets you save data to a local file. It starts by opening a dialog box to let the user enter a new filename and location to which to save a file. After the user selects the filename and location, the data is written to the new file. When the file is saved successfully, the properties of the FileReference object are populated with the properties of the local file.

Note: Your code can only call the FileReference.save() method in response to a user-initiated event such as a mouse click or a keypress event. Otherwise an error is thrown. This restriction does not apply to content running in Adobe AIR in the application security sandbox.

The FileReference.save() method returns immediately after being called. The FileReference object then dispatches events to call listener methods at each step of the file saving process.

The FileReference object dispatches the following events during the file saving process:

  • select event (Event.SELECT): Dispatched when the user specifies the location and file name for the new file to be saved.

  • cancel event (Event.CANCEL): Dispatched when the user click the Cancel button in the dialog box.

  • open event (Event.OPEN): Dispatched when the save operation starts.

  • progress event (ProgressEvent.PROGRESS): Dispatched periodically as bytes of data are saved to the file.

  • complete event (Event.COMPLETE): Dispatched when the save operation completes successfully.

  • ioError event (IOErrorEvent.IO_ERROR): Dispatched if the saving process fails because an input/output error occurs while attempting to save data to the file.

The type of object passed in the data parameter of the FileReference.save() method determines how the data is written to the file:

  • If it is a String value, then it is saved as a text file using UTF-8 encoding.

  • If it is an XML object, then it is written to a file in XML format with all formatting preserved.

  • If it is a ByteArray object, then its contents are written directly to the file with no conversion.

  • If it is some other object, then the FileReference.save() method calls the object’s toString() method and then saves the resulting String value to a UTF-8 text file. If the object’s toString() method can’t be called, then an error is thrown.

If the value of the data parameter is null, then an error is thrown.

The following code extends the previous example for the FileReference.load() method. After reading the data from the file, this example prompts the user for a filename and then saves the data in a new file:

package 
{ 
    import flash.display.Sprite; 
    import flash.events.*;  
    import flash.net.FileFilter; 
    import flash.net.FileReference; 
    import flash.net.URLRequest; 
    import flash.utils.ByteArray; 
 
    public class FileReferenceExample2 extends Sprite 
    { 
        private var fileRef:FileReference; 
        public function FileReferenceExample2() 
        { 
            fileRef = new FileReference(); 
            fileRef.addEventListener(Event.SELECT, onFileSelected); 
            fileRef.addEventListener(Event.CANCEL, onCancel); 
            fileRef.addEventListener(IOErrorEvent.IO_ERROR, onIOError); 
            fileRef.addEventListener(SecurityErrorEvent.SECURITY_ERROR, 
                        onSecurityError); 
            var textTypeFilter:FileFilter = new FileFilter("Text Files (*.txt, *.rtf)", 
                        "*.txt;*.rtf"); 
            fileRef.browse([textTypeFilter]); 
        } 
        public function onFileSelected(evt:Event):void 
        { 
            fileRef.addEventListener(ProgressEvent.PROGRESS, onProgress); 
            fileRef.addEventListener(Event.COMPLETE, onComplete); 
            fileRef.load(); 
        } 
 
        public function onProgress(evt:ProgressEvent):void 
        { 
            trace("Loaded " + evt.bytesLoaded + " of " + evt.bytesTotal + " bytes."); 
        } 
        public function onCancel(evt:Event):void 
        { 
            trace("The browse request was canceled by the user."); 
        } 
        public function onComplete(evt:Event):void 
        { 
            trace("File was successfully loaded."); 
            fileRef.removeEventListener(Event.SELECT, onFileSelected); 
            fileRef.removeEventListener(ProgressEvent.PROGRESS, onProgress); 
            fileRef.removeEventListener(Event.COMPLETE, onComplete); 
            fileRef.removeEventListener(Event.CANCEL, onCancel); 
            saveFile(); 
        } 
        public function saveFile():void 
        { 
            fileRef.addEventListener(Event.SELECT, onSaveFileSelected); 
            fileRef.save(fileRef.data,"NewFileName.txt"); 
        } 
 
        public function onSaveFileSelected(evt:Event):void 
        { 
            fileRef.addEventListener(ProgressEvent.PROGRESS, onSaveProgress); 
            fileRef.addEventListener(Event.COMPLETE, onSaveComplete); 
            fileRef.addEventListener(Event.CANCEL, onSaveCancel); 
        } 
 
        public function onSaveProgress(evt:ProgressEvent):void 
        { 
            trace("Saved " + evt.bytesLoaded + " of " + evt.bytesTotal + " bytes."); 
        } 
         
        public function onSaveComplete(evt:Event):void 
        { 
            trace("File saved."); 
            fileRef.removeEventListener(Event.SELECT, onSaveFileSelected); 
            fileRef.removeEventListener(ProgressEvent.PROGRESS, onSaveProgress); 
            fileRef.removeEventListener(Event.COMPLETE, onSaveComplete); 
            fileRef.removeEventListener(Event.CANCEL, onSaveCancel); 
        } 
 
        public function onSaveCancel(evt:Event):void 
        { 
            trace("The save request was canceled by the user."); 
        } 
 
        public function onIOError(evt:IOErrorEvent):void 
        { 
            trace("There was an IO Error."); 
        } 
        public function onSecurityError(evt:Event):void 
        { 
            trace("There was a security error."); 
        } 
    } 
}

When all of the data loads from the file, the code calls the onComplete() method. The onComplete() method removes the listeners for the loading events and then calls the saveFile() method. The saveFile() method calls the FileReference.save() method. The FileReference.save() method opens a new dialog box to let the user enter a new filename and location to save the file. The remaining event listener methods trace the progress of the file saving process until it is complete.

In Adobe AIR, the FileStream class provides additional functionality for writing data to a local file. See Reading and writing files.

Uploading files to a server

To upload files to a server, first call the browse() method to allow a user to select one or more files. Next, when the FileReference.upload() method is called, the selected file is transferred to the server. If the user selects multiple files using the FileReferenceList.browse() method, Flash Player creates an array of selected files called FileReferenceList.fileList. You can then use the FileReference.upload() method to upload each file individually.

Note: Using the FileReference.browse() method allows you to upload single files only. To allow a user to upload multiple files, use the FileReferenceList.browse() method.

By default, the system file picker dialog box allows users to pick any file type from the local computer. Developers can specify one or more custom file type filters by using the FileFilter class and passing an array of file filter instances to the browse() method:

var imageTypes:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg; *.jpeg; *.gif; *.png"); 
var textTypes:FileFilter = new FileFilter("Text Files (*.txt, *.rtf)", "*.txt; *.rtf"); 
var allTypes:Array = new Array(imageTypes, textTypes); 
var fileRef:FileReference = new FileReference(); 
fileRef.browse(allTypes);

When the user has selected the files and clicked the Open button in the system file picker, the Event.SELECT event is dispatched. If the FileReference.browse() method is used to select a file to upload, the following code sends the file to a web server:

var fileRef:FileReference = new FileReference(); 
fileRef.addEventListener(Event.SELECT, selectHandler); 
fileRef.addEventListener(Event.COMPLETE, completeHandler); 
try 
{ 
    var success:Boolean = fileRef.browse(); 
} 
catch (error:Error) 
{ 
    trace("Unable to browse for files."); 
} 
function selectHandler(event:Event):void 
{ 
    var request:URLRequest = new URLRequest("http://www.[yourdomain].com/fileUploadScript.cfm") 
    try 
    { 
        fileRef.upload(request); 
    } 
    catch (error:Error) 
    { 
        trace("Unable to upload file."); 
    } 
} 
function completeHandler(event:Event):void 
{ 
    trace("uploaded"); 
}
You can send data to the server with the FileReference.upload() method by using the URLRequest.method and URLRequest.data properties to send variables using the POST or GET methods.

When you attempt to upload a file using the FileReference.upload() method, the following events are dispatched:

  • open event (Event.OPEN): Dispatched when the upload operation starts.

  • progress event (ProgressEvent.PROGRESS): Dispatched periodically as bytes of data from the file are uploaded.

  • complete event (Event.COMPLETE): Dispatched when the upload operation completes successfully.

  • httpStatus event (HTTPStatusEvent.HTTP_STATUS): Dispatched when the upload process fails because of an HTTP error.

  • httpResponseStatus event (HTTPStatusEvent.HTTP_RESPONSE_STATUS): Dispatched if a call to the upload() or uploadUnencoded() method attempts to access data over HTTP and Adobe AIR is able to detect and return the status code for the request.

  • securityError event (SecurityErrorEvent.SECURITY_ERROR): Dispatched when an upload operation fails because of a security violation.

  • uploadCompleteData event (DataEvent.UPLOAD_COMPLETE_DATA): Dispatched after data is received from the server after a successful upload.

  • ioError event (IOErrorEvent.IO_ERROR): Dispatched if the upload process fails for any of the following reasons:

    • An input/output error occurred while Flash Player is reading, writing, or transmitting the file.

    • The SWF tried to upload a file to a server that requires authentication (such as a user name and password). During upload, Flash Player does not provide a means for users to enter passwords.

    • The url parameter contains an invalid protocol. The FileReference.upload() method must use either HTTP or HTTPS.

Flash Player does not offer complete support for servers that require authentication. Only SWF files that are running in a browser using the browser plug-in or Microsoft ActiveX® control can provide a dialog box to prompt the user to enter a user name and password for authentication, and then only for downloads. For uploads using the plug-in or ActiveX control or upload/download using either the stand-alone or external player, the file transfer fails.

To create a server script in ColdFusion to accept a file upload from Flash Player, you can use code similar to the following:

<cffile action="upload" filefield="Filedata" destination="#ExpandPath('./')#" nameconflict="OVERWRITE" />

This ColdFusion code uploads the file sent by Flash Player and saves it to the same directory as the ColdFusion template, overwriting any file with the same name. The previous code shows the bare minimum amount of code necessary to accept a file upload; this script should not be used in a production environment. Ideally, add data validation to ensure that users upload only accepted file types, such as an image instead of a potentially dangerous server-side script.

The following code demonstrates file uploads using PHP, and it includes data validation. The script limits the number of uploaded files in the upload directory to 10, ensures that the file is less than 200 KB, and permits only JPEG, GIF, or PNG files to be uploaded and saved to the file system.

<?php 
$MAXIMUM_FILESIZE = 1024 * 200; // 200KB 
$MAXIMUM_FILE_COUNT = 10; // keep maximum 10 files on server 
echo exif_imagetype($_FILES['Filedata']); 
if ($_FILES['Filedata']['size'] <= $MAXIMUM_FILESIZE) 
{ 
    move_uploaded_file($_FILES['Filedata']['tmp_name'], "./temporary/".$_FILES['Filedata']['name']); 
    $type = exif_imagetype("./temporary/".$_FILES['Filedata']['name']); 
    if ($type == 1 || $type == 2 || $type == 3) 
    { 
        rename("./temporary/".$_FILES['Filedata']['name'], "./images/".$_FILES['Filedata']['name']); 
    } 
    else 
    { 
        unlink("./temporary/".$_FILES['Filedata']['name']); 
    } 
} 
$directory = opendir('./images/'); 
$files = array(); 
while ($file = readdir($directory)) 
{ 
    array_push($files, array('./images/'.$file, filectime('./images/'.$file))); 
} 
usort($files, sorter); 
if (count($files) > $MAXIMUM_FILE_COUNT) 
{ 
    $files_to_delete = array_splice($files, 0, count($files) - $MAXIMUM_FILE_COUNT); 
    for ($i = 0; $i < count($files_to_delete); $i++) 
    { 
        unlink($files_to_delete[$i][0]); 
    } 
} 
print_r($files); 
closedir($directory); 
 
function sorter($a, $b) 
{ 
    if ($a[1] == $b[1]) 
    { 
        return 0; 
    } 
    else 
    { 
        return ($a[1] < $b[1]) ? -1 : 1; 
    } 
} 
?>

You can pass additional variables to the upload script using either the POST or GET request method. To send additional POST variables to your upload script, you can use the following code:

var fileRef:FileReference = new FileReference(); 
fileRef.addEventListener(Event.SELECT, selectHandler); 
fileRef.addEventListener(Event.COMPLETE, completeHandler); 
fileRef.browse(); 
function selectHandler(event:Event):void 
{ 
    var params:URLVariables = new URLVariables(); 
    params.date = new Date(); 
    params.ssid = "94103-1394-2345"; 
    var request:URLRequest = new URLRequest("http://www.yourdomain.com/FileReferenceUpload/fileupload.cfm"); 
    request.method = URLRequestMethod.POST; 
    request.data = params; 
    fileRef.upload(request, "Custom1"); 
} 
function completeHandler(event:Event):void 
{ 
    trace("uploaded"); 
}

The previous example creates a URLVariables object that you pass to the remote server- side script. In previous versions of ActionScript, you could pass variables to the server upload script by passing values in the query string. ActionScript 3.0 allows you to pass variables to the remote script using a URLRequest object, which allows you to pass data using either the POST or GET method; this, in turn, makes passing larger sets of data easier and cleaner. In order to specify whether the variables are passed using the GET or POST request method, you can set the URLRequest.method property to either URLRequestMethod.GET or URLRequestMethod.POST, respectively.

ActionScript 3.0 also lets you override the default Filedata upload file field name by providing a second parameter to the upload() method, as demonstrated in the previous example (which replaced the default value Filedata with Custom1).

By default, Flash Player does not attempt to send a test upload, although you can override this default by passing a value of true as the third parameter to the upload() method. The purpose of the test upload is to check whether the actual file upload will be successful and that server authentication, if required, will succeed.

Note: A test upload occurs only on Windows-based Flash Players at this time.

The server script that handles the file upload should expect an HTTP POST request with the following elements:

  • Content-Type with a value of multipart/form-data.

  • Content-Disposition with a name attribute set to “Filedata” and a filename attribute set to the name of the original file. You can specify a custom name attribute by passing a value for the uploadDataFieldName parameter in the FileReference.upload() method.

  • The binary contents of the file.

Here is a sample HTTP POST request:

POST /handler.asp HTTP/1.1 
Accept: text/* 
Content-Type: multipart/form-data; 
boundary=----------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6 
User-Agent: Shockwave Flash 
Host: www.mydomain.com 
Content-Length: 421 
Connection: Keep-Alive 
Cache-Control: no-cache 
 
------------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6  
Content-Disposition: form-data; name="Filename" 
 
sushi.jpg  
------------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6 
Content-Disposition: form-data; name="Filedata"; filename="sushi.jpg" 
Content-Type: application/octet-stream 
 
Test File  
------------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6 
Content-Disposition: form-data; name="Upload" 
 
Submit Query 
------------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6 
(actual file data,,,)

The following sample HTTP POST request sends three POST variables: api_sig, api_key, and auth_token, and uses a custom upload data field name value of "photo":

POST /handler.asp HTTP/1.1 
Accept: text/* 
Content-Type: multipart/form-data; 
boundary=----------Ij5ae0ae0KM7GI3KM7ei4cH2ei4gL6 
User-Agent: Shockwave Flash 
Host: www.mydomain.com 
Content-Length: 421 
Connection: Keep-Alive 
Cache-Control: no-cache 
 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="Filename" 
 
sushi.jpg 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="api_sig" 
 
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="api_key" 
 
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="auth_token" 
 
XXXXXXXXXXXXXXXXXXXXXXX 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="photo"; filename="sushi.jpg" 
Content-Type: application/octet-stream 
 
(actual file data,,,) 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7 
Content-Disposition: form-data; name="Upload" 
 
Submit Query 
------------Ij5GI3GI3ei4GI3ei4KM7GI3KM7KM7--

Downloading files from a server

You can let users download files from a server using the FileReference.download() method, which takes two parameters: request and defaultFileName. The first parameter is the URLRequest object that contains the URL of the file to download. The second parameter is optional—it lets you specify a default filename that appears in the download file dialog box. If you omit the second parameter, defaultFileName, the filename from the specified URL is used.

The following code downloads a file named index.xml from the same directory as the SWF file:

var request:URLRequest = new URLRequest("index.xml"); 
var fileRef:FileReference = new FileReference(); 
fileRef.download(request);

To set the default name to currentnews.xml instead of index.xml, specify the defaultFileName parameter, as the following snippet shows:

var request:URLRequest = new URLRequest("index.xml"); 
var fileToDownload:FileReference = new FileReference(); 
fileToDownload.download(request, "currentnews.xml");

Renaming a file can be useful if the server filename was not intuitive or was server-generated. It’s also good to explicitly specify the defaultFileName parameter when you download a file using a server-side script, instead of downloading the file directly. For example, you need to specify the defaultFileName parameter if you have a server-side script that downloads specific files based on URL variables passed to it. Otherwise, the default name of the downloaded file is the name of your server-side script.

Data can be sent to the server using the download() method by appending parameters to the URL for the server script to parse. The following ActionScript 3.0 snippet downloads a document based on which parameters are passed to a ColdFusion script:

package 
{ 
    import flash.display.Sprite; 
    import flash.net.FileReference; 
    import flash.net.URLRequest; 
    import flash.net.URLRequestMethod; 
    import flash.net.URLVariables; 
 
    public class DownloadFileExample extends Sprite 
    { 
        private var fileToDownload:FileReference; 
        public function DownloadFileExample() 
        { 
            var request:URLRequest = new URLRequest(); 
            request.url = "http://www.[yourdomain].com/downloadfile.cfm"; 
            request.method = URLRequestMethod.GET; 
            request.data = new URLVariables("id=2"); 
            fileToDownload = new FileReference(); 
            try 
            { 
                fileToDownload.download(request, "file2.txt"); 
            } 
            catch (error:Error) 
            { 
                trace("Unable to download file."); 
            } 
        } 
    } 
}

The following code demonstrates the ColdFusion script, download.cfm, that downloads one of two files from the server, depending on the value of a URL variable:

<cfparam name="URL.id" default="1" /> 
<cfswitch expression="#URL.id#"> 
    <cfcase value="2"> 
        <cfcontent type="text/plain" file="#ExpandPath('two.txt')#" deletefile="No" /> 
    </cfcase> 
    <cfdefaultcase> 
        <cfcontent type="text/plain" file="#ExpandPath('one.txt')#" deletefile="No" /> 
    </cfdefaultcase> 
</cfswitch>

FileReferenceList class

The FileReferenceList class lets the user select one or more files to upload to a server-side script. The file upload is handled by the FileReference.upload() method, which must be called on each file that the user selects.

The following code creates two FileFilter objects (imageFilter and textFilter) and passes them in an array to the FileReferenceList.browse() method. This causes the operating system file dialog box to display two possible filters for file types.

var imageFilter:FileFilter = new FileFilter("Image Files (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg; *.jpeg; *.gif; *.png"); 
var textFilter:FileFilter = new FileFilter("Text Files (*.txt, *.rtf)", "*.txt; *.rtf"); 
var fileRefList:FileReferenceList = new FileReferenceList(); 
try 
{ 
    var success:Boolean = fileRefList.browse(new Array(imageFilter, textFilter)); 
} 
catch (error:Error)  
{ 
    trace("Unable to browse for files."); 
}

Allowing the user to select and upload one or more files by using the FileReferenceList class is the same as using FileReference.browse() to select files, although the FileReferenceList allows you to select more than one file. Uploading multiple files requires you to upload each of the selected files by using FileReference.upload(), as the following code shows:

var fileRefList:FileReferenceList = new FileReferenceList(); 
fileRefList.addEventListener(Event.SELECT, selectHandler); 
fileRefList.browse(); 
 
function selectHandler(event:Event):void 
{ 
    var request:URLRequest = new URLRequest("http://www.[yourdomain].com/fileUploadScript.cfm"); 
    var file:FileReference; 
    var files:FileReferenceList = FileReferenceList(event.target); 
    var selectedFileArray:Array = files.fileList; 
    for (var i:uint = 0; i < selectedFileArray.length; i++) 
    { 
        file = FileReference(selectedFileArray[i]); 
        file.addEventListener(Event.COMPLETE, completeHandler); 
        try 
        { 
            file.upload(request); 
        } 
        catch (error:Error) 
        { 
            trace("Unable to upload files."); 
        } 
    } 
} 
function completeHandler(event:Event):void 
{ 
    trace("uploaded"); 
}

Because the Event.COMPLETE event is added to each individual FileReference object in the array, Flash Player calls the completeHandler() method when each individual file finishes uploading.