repo_zf1/documentation/manual/en/module_specs/Zend_File_Transfer-Introduction.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
<sect1 id="zend.file.transfer.introduction">

    <title>Zend_File_Transfer</title>

    <para>
        <classname>Zend_File_Transfer</classname> 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 <classname>Zend_File_Transfer</classname> to expose
        the same <acronym>API</acronym> for transport protocols like <acronym>HTTP</acronym>, FTP,
        WEBDAV and more.
    </para>

    <note>
        <title>Limitation</title>
        <para>
            The current implementation of <classname>Zend_File_Transfer</classname> is limited to
            <acronym>HTTP</acronym> 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
            <classname>Zend_File_Transfer_Adapter_Http</classname> directly. As soon as
            there are multiple adapters available you can use a common interface.
        </para>
    </note>

    <note>
        <title>Forms</title>
        <para>
            When you are using <classname>Zend_Form</classname> you should use the
            <acronym>API</acronym>s provided by <classname>Zend_Form</classname> and not
            <classname>Zend_File_Transfer</classname> directly. The file transfer support in
            <classname>Zend_Form</classname> is implemented with
            <classname>Zend_File_Transfer</classname>, so the information in this chapter may
            be useful for advanced users of <classname>Zend_Form</classname>.
        </para>
    </note>

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

    <example id="zend.file.transfer.introduction.example">
        <title>Simple Form for Uploading Files</title>
        <para>
            This example illustrates basic file uploading.
            The first part is the file form. In our example there is one file to upload.
        </para>
        <programlisting language="xml"><![CDATA[
<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>
]]></programlisting>
        <para>
           For convenience, you can use <link
               linkend="zend.form.standardElements.file">Zend_Form_Element_File</link> instead of
           building the HTML manually.
        </para>
        <para>
            The next step is to create the receiver of the upload. In our example the receiver is
            located at <code>/file/upload</code>. So next we will create the <code>file</code>
            controller and the <code>upload</code> action.
        </para>
        <programlisting language="php"><![CDATA[
$adapter = new Zend_File_Transfer_Adapter_Http();

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

if (!$adapter->receive()) {
    $messages = $adapter->getMessages();
    echo implode("\n", $messages);
}
]]></programlisting>
        <para>
            This code listing demonstrates the simplest usage of
            <classname>Zend_File_Transfer</classname>. A local destination is set with the
            <code>setDestination</code> method, then the <methodname>receive()</methodname> method
            is called. if there are any upload errors, an error will be returned.
        </para>

    </example>

    <note>
        <title>Attention</title>
        <para>
            This example is suitable only for demonstrating the basic <acronym>API</acronym> of
            <classname>Zend_File_Transfer</classname>. You should <emphasis>never</emphasis> use
            this code listing in a production environment, because severe security issues may be
            introduced. You should always use validators to increase security.
        </para>
    </note>

    <sect2 id="zend.file.transfer.introduction.adapters">

        <title>Supported Adapters for Zend_File_Transfer</title>

        <para>
            <classname>Zend_File_Transfer</classname> is designed to support a variety of adapters
            and transfer directions. With <classname>Zend_File_Transfer</classname> you can upload,
            download and even forward (upload one adapter and download with another adapter at the
            same time) files.
        </para>
    </sect2>

    <sect2 id="zend.file.transfer.introduction.options">

        <title>Options for Zend_File_Transfer</title>

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

        <itemizedlist>
            <listitem>
                <para>
                    <emphasis>ignoreNoFile</emphasis>: If this option is set to
                    <constant>TRUE</constant>, all validators will ignore files that have not been
                    uploaded by the form. The default value is <constant>FALSE</constant> which
                    results in an error if no files were specified.
                </para>
            </listitem>
        </itemizedlist>
    </sect2>

    <sect2 id="zend.file.transfer.introduction.checking">

        <title>Checking Files</title>

        <para>
            <classname>Zend_File_Transfer</classname> 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:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <emphasis>isValid($files = null)</emphasis>: 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
                    <methodname>isValid()</methodname> before calling
                    <methodname>receive()</methodname>; in this case,
                    <methodname>receive()</methodname> will not call <code>isValid</code> internally
                    again when receiving the file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>isUploaded($files = null)</emphasis>: 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.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>isReceived($files = null)</emphasis>: This method will check if the
                    given files have already been received. When no files are specified, all files
                    will be checked.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.introduction.checking.example">
            <title>Checking Files</title>

            <programlisting language="php"><![CDATA[
$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();
]]></programlisting>

        </example>
    </sect2>

    <sect2 id="zend.file.transfer.introduction.informations">

        <title>Additional File Informations</title>

        <para>
            <classname>Zend_File_Transfer</classname> can return additional information on files.
            The following methods are available:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <emphasis>getFileName($file = null, $path = true)</emphasis>: This method
                    will return the real file name of a transferred file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>getFileInfo($file = null)</emphasis>: This method will return all
                    internal information for the given file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>getFileSize($file = null)</emphasis>: This method will return the
                    real filesize for the given file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>getHash($hash = 'crc32', $files = null)</emphasis>: This method
                    returns a hash of the content of a given transferred file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <emphasis>getMimeType($files = null)</emphasis>: This method returns the
                    mimetype of a given transferred file.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            <methodname>getFileName()</methodname> 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.
        </para>

        <para>
            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, <varname>$path</varname>, which
            will truncate the file path when set to <constant>FALSE</constant>.
        </para>

        <example id="zend.file.transfer.introduction.informations.example1">
            <title>Getting the Filename</title>

            <programlisting language="php"><![CDATA[
$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');
]]></programlisting>

        </example>

        <note>
            <para>
                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
                <methodname>getFileName()</methodname> after the files have been received.
            </para>
        </note>

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

        <example id="zend.file.transfer.introduction.informations.example.getfilesize">
            <title>Getting the size of a file</title>

            <programlisting language="php"><![CDATA[
$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();
]]></programlisting>

        </example>

        <para>
            <methodname>getHash()</methodname> accepts the name of a hash algorithm as first
            parameter. For a list of known algorithms refer to
            <ulink url="http://php.net/hash_algos">PHP's hash_algos method</ulink>. If you don't
            specify an algorithm, the <code>crc32</code> algorithm will be used by default.
        </para>

        <example id="zend.file.transfer.introduction.informations.example2">
            <title>Getting the hash of a file</title>

            <programlisting language="php"><![CDATA[
$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');
]]></programlisting>

        </example>

        <note>
            <para>
                Note that if the given file or form name contains more than one file, the returned
                value will be an array.
            </para>
        </note>

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

        <example id="zend.file.transfer.introduction.informations.getmimetype">
            <title>Getting the mimetype of a file</title>

            <programlisting language="php"><![CDATA[
$upload = new Zend_File_Transfer();
$upload->receive();

$mime = $upload->getMimeType();

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

        </example>

        <note>
            <para>
                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.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.introduction.uploadprogress">

        <title>Progress for file uploads</title>

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

        <para>
            First, you need to have either <acronym>APC</acronym> or <code>uploadprogress</code> to
            be enabled. Note that you can disable this feature of <acronym>APC</acronym> within your
            php.ini.
        </para>

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

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

        <sect3 id="zend.file.transfer.introduction.uploadprogress.progressadapter">

            <title>Using a progressbar adapter</title>

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

            <para>
                To archive this, you have to add the wished
                <emphasis>Zend_ProgressBar_Adapter</emphasis> to
                <methodname>getProgress()</methodname> when you are calling it the first time. For
                details about the right adapter to use, look into the chapter <link
                    linkend="zend.progressbar.adapters">Zend_ProgressBar Standard Adapters</link>.
            </para>

            <example id="zend.file.transfer.introduction.uploadprogress.progressadapter.example1">

                <title>Using the progressbar adapter to retrieve the actual state</title>

                <programlisting language="php"><![CDATA[
$adapter = new Zend_ProgressBar_Adapter_Console();
$upload  = Zend_File_Transfer_Adapter_Http::getProgress($adapter);

$upload = null;
while (!$upload['done']) {
    $upload = Zend_File_Transfer_Adapter_Http:getProgress($upload);
}
]]></programlisting>

            </example>

            <para>
                The complete handling is done by <methodname>getProgress()</methodname> for you in
                the background.
            </para>

        </sect3>

        <sect3 id="zend.file.transfer.introduction.uploadprogress.manually">

            <title>Using getProgress() manually</title>

            <para>
                You can also work manually with <methodname>getProgress()</methodname> without the
                usage of <classname>Zend_ProgressBar</classname>.
            </para>

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

            <itemizedlist>
                <listitem>
                    <para>
                        <emphasis>id</emphasis>: The ID of this upload. This ID identifies the
                        upload within the extension. It is filled automatically. You should never
                        change or give this value yourself.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>total</emphasis>: The total filesize of the uploaded files in
                        bytes as integer.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>current</emphasis>: The current uploaded filesize in bytes
                        as integer.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>rate</emphasis>: The average upload speed in bytes per second
                        as integer.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>done</emphasis>: Returns <constant>TRUE</constant> when the upload
                        is finished and <constant>FALSE</constant> otherwise.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>message</emphasis>: The actual message. Either the progress as
                        text in the form <emphasis>10kB / 200kB</emphasis>, 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.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>progress</emphasis>: This optional key takes a instance of
                        <classname>Zend_ProgressBar_Adapter</classname> or
                        <classname>Zend_ProgressBar</classname> and allows to get the actual upload
                        state within a progressbar.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        <emphasis>session</emphasis>: This optional key takes the name of a session
                        namespace which will be used within <classname>Zend_ProgressBar</classname>.
                        When this key is not given it defaults to
                        <classname>Zend_File_Transfer_Adapter_Http_ProgressBar</classname>.
                    </para>
                </listitem>
            </itemizedlist>

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

            <para>
                The following example shows a possible manual usage:
            </para>

            <example id="zend.file.transfer.introduction.uploadprogress.manually.example1">

                <title>Manual usage of the file progress</title>

                <programlisting language="php"><![CDATA[
$upload  = Zend_File_Transfer_Adapter_Http::getProgress();

while (!$upload['done']) {
    $upload = Zend_File_Transfer_Adapter_Http:getProgress($upload);
    print "\nActual progress:".$upload['message'];
    // do whatever you need
}
]]></programlisting>

            </example>

        </sect3>

    </sect2>

</sect1>
<!--
vim:se ts=4 sw=4 tw=80 et:
-->