Zend_File_Transfer

Zend_File_Transfer provides extensive support for file uploads and downloads. It comes with built-in validators for files plus functionality to change files with filters. Protocol adapters allow Zend_File_Transfer to expose the same API for transport protocols like HTTP, FTP, WEBDAV and more.

Note: Limitation
The current implementation of Zend_File_Transfer is limited to HTTP Post Uploads. Other adapters supporting downloads and other protocols will be added in future releases. Unimplemented methods will throw an exception. For now, you should use Zend_File_Transfer_Adapter_Http directly. As soon as there are multiple adapters available you can use a common interface.

Note: Forms
When you are using Zend_Form you should use the APIs provided by Zend_Form and not Zend_File_Transfer directly. The file transfer support in Zend_Form is implemented with Zend_File_Transfer, so the information in this chapter may be useful for advanced users of Zend_Form.

The usage of Zend_File_Transfer is relatively simple. It consists of two parts. The HTTP form does the upload, while the Zend_File_Transfer handles the uploaded files. See the following example:

Example #1 Simple Form for Uploading Files

This example illustrates basic file uploading. The first part is the file form. In our example there is one file to upload.

  1. <form enctype="multipart/form-data" action="/file/upload" method="POST">
  2.     <input type="hidden" name="MAX_FILE_SIZE" value="100000" />
  3.         Choose a file to upload: <input name="uploadedfile" type="file" />
  4.     <br />
  5.     <input type="submit" value="Upload File" />
  6. </form>

For convenience, you can use Zend_Form_Element_File instead of building the HTML manually.

The next step is to create the receiver of the upload. In our example the receiver is located at /file/upload. So next we will create the 'file' controller and the upload() action.

  1. $adapter = new Zend_File_Transfer_Adapter_Http();
  2.  
  3. $adapter->setDestination('C:\temp');
  4.  
  5. if (!$adapter->receive()) {
  6.     $messages = $adapter->getMessages();
  7.     echo implode("\n", $messages);
  8. }

This code listing demonstrates the simplest usage of Zend_File_Transfer. A local destination is set with the setDestination() method, then the receive() method is called. if there are any upload errors, an error will be returned.

Note: Attention
This example is suitable only for demonstrating the basic API of Zend_File_Transfer. You should never use this code listing in a production environment, because severe security issues may be introduced. You should always use validators to increase security.

Supported Adapters for Zend_File_Transfer

Zend_File_Transfer is designed to support a variety of adapters and transfer directions. With Zend_File_Transfer you can upload, download and even forward (upload one adapter and download with another adapter at the same time) files.

Options for Zend_File_Transfer

Zend_File_Transfer and its adapters support different options. You can set all options either by passing them to the constructor or by calling setOptions($options). getOptions() will return the options that are currently set. The following is a list of all supported options.

  • ignoreNoFile: If this option is set to TRUE, all validators will ignore files that have not been uploaded by the form. The default value is FALSE which results in an error if no files were specified.

Checking Files

Zend_File_Transfer has several methods that check for various states of the specified file. These are useful if you must process files after they have been uploaded. These methods include:

  • isValid($files = null): This method will check if the given files are valid, based on the validators that are attached to the files. If no files are specified, all files will be checked. You can call isValid() before calling receive(); in this case, receive() will not call isValid() internally again when receiving the file.

  • isUploaded($files = null): This method will check if the specified files have been uploaded by the user. This is useful when you have defined one or more optional files. When no files are specified, all files will be checked.

  • isReceived($files = null): This method will check if the given files have already been received. When no files are specified, all files will be checked.

Example #2 Checking Files

  1. $upload = new Zend_File_Transfer();
  2.  
  3. // Returns all known internal file information
  4. $files = $upload->getFileInfo();
  5.  
  6. foreach ($files as $file => $info) {
  7.     // file uploaded ?
  8.     if (!$upload->isUploaded($file)) {
  9.         print "Why havn't you uploaded the file ?";
  10.         continue;
  11.     }
  12.  
  13.     // validators are ok ?
  14.     if (!$upload->isValid($file)) {
  15.         print "Sorry but $file is not what we wanted";
  16.         continue;
  17.     }
  18. }
  19.  
  20. $upload->receive();

Additional File Informations

Zend_File_Transfer can return additional information on files. The following methods are available:

  • getFileName($file = null, $path = true): This method will return the real file name of a transferred file.

  • getFileInfo($file = null): This method will return all internal information for the given file.

  • getFileSize($file = null): This method will return the real filesize for the given file.

  • getHash($hash = 'crc32', $files = null): This method returns a hash of the content of a given transferred file.

  • getMimeType($files = null): This method returns the mimetype of a given transferred file.

getFileName() accepts the name of the element as first parameter. If no name is given, all known filenames will be returned in an array. If the file is a multifile, you will also get an array. If there is only a single file a string will be returned.

By default file names will be returned with the complete path. If you only need the file name without path, you can set the second parameter, $path, which will truncate the file path when set to FALSE.

Example #3 Getting the Filename

  1. $upload = new Zend_File_Transfer();
  2. $upload->receive();
  3.  
  4. // Returns the file names from all files
  5. $names = $upload->getFileName();
  6.  
  7. // Returns the file names from the 'foo' form element
  8. $names = $upload->getFileName('foo');

Note: Note that the file name can change after you receive the file, because all filters will be applied once the file is received. So you should always call getFileName() after the files have been received.

getFileSize() returns per default the real filesize in SI notation which means you will get 2kB instead of 2048. If you need only the plain size set the useByteString option to FALSE.

Example #4 Getting the size of a file

  1. $upload = new Zend_File_Transfer();
  2. $upload->receive();
  3.  
  4. // Returns the sizes from all files as array if more than one file was uploaded
  5. $size = $upload->getFileSize();
  6.  
  7. // Switches of the SI notation to return plain numbers
  8. $upload->setOption(array('useByteString' => false));
  9. $size = $upload->getFileSize();

Note: Client given filesize
Note that the filesize which is given by the client is not seen as save input. Therefor the real size of the file will be detected and returned instead of the filesize sent by the client.

getHash() accepts the name of a hash algorithm as first parameter. For a list of known algorithms refer to » PHP's hash_algos method. If you don't specify an algorithm, the crc32 algorithm will be used by default.

Example #5 Getting the hash of a file

  1. $upload = new Zend_File_Transfer();
  2. $upload->receive();
  3.  
  4. // Returns the hashes from all files as array if more than one file was uploaded
  5. $hash = $upload->getHash('md5');
  6.  
  7. // Returns the hash for the 'foo' form element
  8. $names = $upload->getHash('crc32', 'foo');

Note: Return value
Note that if the given file or form name contains more than one file, the returned value will be an array.

getMimeType() returns the mimetype of a file. If more than one file was uploaded it returns an array, otherwise a string.

Example #6 Getting the mimetype of a file

  1. $upload = new Zend_File_Transfer();
  2. $upload->receive();
  3.  
  4. $mime = $upload->getMimeType();
  5.  
  6. // Returns the mimetype for the 'foo' form element
  7. $names = $upload->getMimeType('foo');

Note: Client given mimetype
Note that the mimetype which is given by the client is not seen as save input. Therefor the real mimetype of the file will be detected and returned instead of the mimetype sent by the client.

Warning

Possible exception

Note that this method uses the fileinfo extension if it is available. If this extension can not be found, it uses the mimemagic extension. When no extension was found it raises an exception.

Warning

Original data within $_FILES

Due to security reasons also the original data within $_FILES will be overridden as soon as Zend_File_Transfer is initiated. When you want to omit this behaviour and have the original data simply set the detectInfos option to FALSE at initiation.

This option will have no effect after you initiated Zend_File_Transfer.

Progress for file uploads

Zend_File_Transfer can give you the actual state of a fileupload in progress. To use this feature you need either the APC extension which is provided with most default PHP installations, or the UploadProgress extension. Both extensions are detected and used automatically. To be able to get the progress you need to meet some prerequisites.

First, you need to have either APC or UploadProgress to be enabled. Note that you can disable this feature of APC within your php.ini.

Second, you need to have the proper hidden fields added in the form which sends the files. When you use Zend_Form_Element_File this hidden fields are automatically added by Zend_Form.

When the above two points are provided then you are able to get the actual progress of the file upload by using the getProgress() method. Actually there are 2 official ways to handle this.

Using a progressbar adapter

You can use the convinient Zend_ProgressBar to get the actual progress and can display it in a simple manner to your user.

To archive this, you have to add the wished Zend_ProgressBar_Adapter to getProgress() when you are calling it the first time. For details about the right adapter to use, look into the chapter Zend_ProgressBar Standard Adapters.

Example #7 Using the progressbar adapter to retrieve the actual state

  1. $adapter = new Zend_ProgressBar_Adapter_Console();
  2. $upload  = Zend_File_Transfer_Adapter_Http::getProgress($adapter);
  3.  
  4. $upload = null;
  5. while (!$upload['done']) {
  6.     $upload = Zend_File_Transfer_Adapter_Http:getProgress($upload);
  7. }

The complete handling is done by getProgress() for you in the background.

Using getProgress() manually

You can also work manually with getProgress() without the usage of Zend_ProgressBar.

Call getProgress() without settings. It will return you an array with several keys. They differ according to the used PHP extension. But the following keys are given independently of the extension:

  • id: The ID of this upload. This ID identifies the upload within the extension. You can set it to the value of the hidden key which identified the upload when initially calling getProgress(). Per default it is set to progress_key. You must not change the ID afterwards.

  • total: The total filesize of the uploaded files in bytes as integer.

  • current: The current uploaded filesize in bytes as integer.

  • rate: The average upload speed in bytes per second as integer.

  • done: Returns TRUE when the upload is finished and FALSE otherwise.

  • message: The actual message. Either the progress as text in the form 10kB / 200kB, or a helpful message in the case of a problem. Problems could be, that there is no upload in progress, that there was a failure while retrieving the data for the progress, or that the upload has been canceled.

  • progress: This optional key takes a instance of Zend_ProgressBar_Adapter or Zend_ProgressBar and allows to get the actual upload state within a progressbar.

  • session: This optional key takes the name of a session namespace which will be used within Zend_ProgressBar. When this key is not given it defaults to Zend_File_Transfer_Adapter_Http_ProgressBar.

All other returned keys are provided directly from the extensions and will not be checked.

The following example shows a possible manual usage:

Example #8 Manual usage of the file progress

  1. $upload  = Zend_File_Transfer_Adapter_Http::getProgress();
  2.  
  3. while (!$upload['done']) {
  4.     $upload = Zend_File_Transfer_Adapter_Http:getProgress($upload);
  5.     print "\nActual progress:".$upload['message'];
  6.     // do whatever you need
  7. }

Note: Knowing the file to get the progress from
The above example works when your upload identified is set to 'progress_key'. When you are using another identifier within your form you must give the used identifier as first parameter to getProgress() on the initial call.

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