Programmer's Reference Guide

Zend_File

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.

Замечание: 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.

Замечание: 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:

Пример #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.

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

$adapter = new Zend_File_Transfer_Adapter_Http();

$adapter->setDestination('C:\temp');

if (!$adapter->receive()) {
    $messages = $adapter->getMessages();
    echo implode("\n", $messages);
}

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.

Замечание: 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.

Пример #2 Checking Files

$upload = new Zend_File_Transfer();

// Returns all known internal file information
$files = $upload->getFileInfo();

foreach ($files as $file => $info) {
    // file uploaded ?
    if (!$upload->isUploaded($file)) {
        print "Why havn't you uploaded the file ?";
        continue;
    }

    // validators are ok ?
    if (!$upload->isValid($file)) {
        print "Sorry but $file is not what we wanted";
        continue;
    }
}

$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.

Пример #3 Getting the Filename

$upload = new Zend_File_Transfer();
$upload->receive();

// Returns the file names from all files
$names = $upload->getFileName();

// Returns the file names from the 'foo' form element
$names = $upload->getFileName('foo');

Замечание: 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.

Пример #4 Getting the size of a file

$upload = new Zend_File_Transfer();
$upload->receive();

// Returns the sizes from all files as array if more than one file was uploaded
$size = $upload->getFileSize();

// Switches of the SI notation to return plain numbers
$upload->setOption(array('useByteString' => false));
$size = $upload->getFileSize();

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.

Пример #5 Getting the hash of a file

$upload = new Zend_File_Transfer();
$upload->receive();

// Returns the hashes from all files as array if more than one file was uploaded
$hash = $upload->getHash('md5');

// Returns the hash for the 'foo' form element
$names = $upload->getHash('crc32', 'foo');

Замечание: 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.

Пример #6 Getting the mimetype of a file

$upload = new Zend_File_Transfer();
$upload->receive();

$mime = $upload->getMimeType();

// Returns the mimetype for the 'foo' form element
$names = $upload->getMimeType('foo');

Замечание: 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 uses the mimetype given by the fileserver when the file was uploaded.

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 prerequisits.

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.

Пример #7 Retrieve the actual progress of the file upload

Let's expect that you have already created and submitted your form, and the file upload is actually in progress.

$upload = Zend_File_Transfer_Adapter_Http::getProgress();

$upload = null;
while (empty($upload['message'])) {
    $upload = Zend_File_Transfer_Adapter_Http:getProgress($upload);
    // do something with the returned data
}

Based on the used extension the returned data differs in detail. But both extensions return their informations within an array which provides the following keys:

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.
id: The id is the reference to the upload itself. When multiple users upload a file, each upload get's it's own id. The actual id of this request will be returned when you call getProgress() the first time.
message: A helpfull 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 progrss, or that the upload has been canceled.