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<sect1 id="zend.file.transfer.validators">

    <title>Validators for Zend_File_Transfer</title>

    <para>
        <classname>Zend_File_Transfer</classname> is delivered with several file-related validators
        which can be used to increase security and prevent possible attacks. Note that these
        validators are only as effective as how effectively you apply them. All validators provided
        with <classname>Zend_File_Transfer</classname> can be found in the
        <classname>Zend_Validator</classname> component and are named
        <classname>Zend_Validate_File_*</classname>. The following validators are available:
    </para>

    <itemizedlist>
        <listitem>
            <para>
                <code>Count</code>: This validator checks for the number of files. A minimum and
                maximum range can be specified. An error will be thrown if either limit is crossed.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Crc32</code>: This validator checks for the crc32 hash value of the content
                from a file. It is based on the <code>Hash</code> validator and provides a
                convenient and simple validator that only supports Crc32.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>ExcludeExtension</code>: This validator checks the extension of files. It will
                throw an error when an given file has a defined extension. With this validator, you
                can exclude defined extensions from being validated.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>ExcludeMimeType</code>: This validator validates the <acronym>MIME</acronym>
                type of files. It can also validate <acronym>MIME</acronym> types and will throw an
                error if the <acronym>MIME</acronym> type of specified file matches.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Exists</code>: This validator checks for the existence of files. It will throw
                an error when a specified file does not exist.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Extension</code>: This validator checks the extension of files. It will throw
                an error when a specified file has an undefined extension.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>FilesSize</code>: This validator checks the size of validated files.
                It remembers internally the size of all checked files and throws an error when the
                sum of all specified files exceed the defined size. It also provides minimum and
                maximum values.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>ImageSize</code>: This validator checks the size of image. It validates the
                width and height and enforces minimum and maximum dimensions.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>IsCompressed</code>: This validator checks whether the file is compressed. It
                is based on the <code>MimeType</code> validator and validates for compression
                archives like zip or arc. You can also limit it to other archives.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>IsImage</code>: This validator checks whether the file is an image. It is
                based on the <code>MimeType</code> validator and validates for image files like jpg
                or gif. You can also limit it to other image types.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Hash</code>: This validator checks the hash value of the content from a file.
                It supports multiple algorithms.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Md5</code>: This validator checks for the md5 hash value of the content from a
                file. It is based on the <code>Hash</code> validator and provides a convenient and
                simple validator that only supports Md5.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>MimeType</code>: This validator validates the <acronym>MIME</acronym> type of
                files. It can also validate <acronym>MIME</acronym> types and will throw an error if
                the <acronym>MIME</acronym> type of a specified file does not match.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>NotExists</code>: This validator checks for the existence of files. It will
                throw an error when an given file does exist.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Sha1</code>: This validator checks for the sha1 hash value of the content from
                a file. It is based on the <code>Hash</code> validator and provides a convenient and
                simple validator that only supports sha1.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Size</code>: This validator is able to check files for its file size. It
                provides a minimum and maximum size range and will throw an error when either of
                these thesholds are crossed.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>Upload</code>: This validator is internal. It checks if an upload has
                resulted in an error. You must not set it, as it's automatically set by
                <classname>Zend_File_Transfer</classname> itself. So you do not use this validator
                directly. You should only know that it exists.
            </para>
        </listitem>

        <listitem>
            <para>
                <code>WordCount</code>: This validator is able to check the number of words within
                files. It provides a minimum and maximum count and will throw an error when either
                of these thresholds are crossed.
            </para>
        </listitem>
    </itemizedlist>

    <sect2 id="zend.file.transfer.validators.usage">
        <title>Using Validators with Zend_File_Transfer</title>

        <para>
            Putting validators to work is quite simple. There are several methods for adding and
            manipulating validators:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <methodname>isValid($files = null)</methodname>: Checks the specified files
                    using all validators. <varname>$files</varname> may be either a real filename,
                    the element's name or the name of the temporary file.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>addValidator($validator, $breakChainOnFailure, $options = null, $files =
                    null)</code>: Adds the specified validator to the validator
                    stack (optionally only to the file(s) specified).
                    <varname>$validator</varname> may be either an actual validator
                    instance or a short name specifying the validator type (e.g., 'Count').
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>addValidators(array $validators, $files =
                        null)</code>: Adds the specified validators to the stack of
                    validators. Each entry may be either a validator
                    type/options pair or an array with the key 'validator'
                    specifying the validator. All other options will be
                    considered validator options for instantiation.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>setValidators(array $validators, $files =
                        null)</code>: Overwrites any existing validators with
                    the validators specified. The validators should follow the
                    syntax for <methodname>addValidators()</methodname>.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>hasValidator($name)</methodname>: Indicates whether a
                    validator has been registered.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>getValidator($name)</methodname>: Returns a previously
                    registered validator.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>getValidators($files = null)</methodname>: Returns
                    registered validators. If <varname>$files</varname> is specified,
                    returns validators for that particular file or set of
                    files.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>removeValidator($name)</methodname>: Removes a previously
                    registered validator.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>clearValidators()</methodname>: Clears all
                    registered validators.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.validators.usage.example">
            <title>Add Validators to a File Transfer Object</title>

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

// Set a file size with 20000 bytes
$upload->addValidator('Size', false, 20000);

// Set a file size with 20 bytes minimum and 20000 bytes maximum
$upload->addValidator('Size', false, array('min' => 20, 'max' => 20000));

// Set a file size with 20 bytes minimum and 20000 bytes maximum and
// a file count in one step
$upload->setValidators(array(
    'Size'  => array('min' => 20, 'max' => 20000),
    'Count' => array('min' => 1, 'max' => 3),
));
]]></programlisting>
        </example>

        <example id="zend.file.transfer.validators.usage.exampletwo">
            <title>Limit Validators to Single Files</title>

            <para>
                <methodname>addValidator()</methodname>, <methodname>addValidators()</methodname>,
                and <methodname>setValidators()</methodname> each accept a final
                <varname>$files</varname> argument. This argument can be used to
                specify a particular file or array of files on which to set the
                given validator.
            </para>

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

// Set a file size with 20000 bytes and limits it only to 'file2'
$upload->addValidator('Size', false, 20000, 'file2');
]]></programlisting>
        </example>

        <para>
            Normally, you should use the <methodname>addValidators()</methodname> method, which
            can be called multiple times.
        </para>

        <example id="zend.file.transfer.validators.usage.examplemultiple">
            <title>Add Multiple Validators</title>

            <para>
                Often it's simpler just to call <methodname>addValidator()</methodname> multiple
                times with one call for each validator. This also increases readability and makes
                your code more maintainable. All methods provide a fluent interface, so you can
                couple the calls as shown below:
            </para>

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

// Set a file size with 20000 bytes
$upload->addValidator('Size', false, 20000)
       ->addValidator('Count', false, 2)
       ->addValidator('Filessize', false, 25000);
]]></programlisting>

        </example>

        <note>
            <para>
                Note that setting the same validator
                multiple times is allowed, but doing so can lead to issues when using
                different options for the same validator.
            </para>
        </note>

        <para>
            Last but not least, you can simply check the files using
            <methodname>isValid()</methodname>.
        </para>

        <example id="zend.file.transfer.validators.usage.exampleisvalid">
            <title>Validate the Files</title>

            <para>
                <methodname>isValid()</methodname> accepts the file name of the uploaded or
                downloaded file, the temporary file name and or the name of the form element. If
                no parameter or null is given all files will be validated
            </para>

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

// Set a file size with 20000 bytes
$upload->addValidator('Size', false, 20000)
       ->addValidator('Count', false, 2)
       ->addValidator('Filessize', false, 25000);

if ($upload->isValid()) {
    print "Validation failure";
}
]]></programlisting>

        </example>

        <note>
            <para>
                Note that <methodname>isValid()</methodname> will be called automatically when you
                receive the files and have not called it previously.
            </para>
        </note>

        <para>
            When validation has failed it is a good idea to get information about the
            problems found. To get this information, you can use the methods
            <methodname>getMessages()</methodname> which returns all validation messages as array,
            <methodname>getErrors()</methodname> which returns all error codes, and
            <methodname>hasErrors()</methodname> which returns true as soon as a validation error
            has been found.
        </para>

    </sect2>

    <sect2 id="zend.file.transfer.validators.count">
        <title>Count Validator</title>

        <para>
            The <code>Count</code> validator checks for the number of files which are provided. It
            supports the following option keys:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>min</code>: Sets the minimum number of files to transfer.
                </para>

                <note>
                    <para>
                        When using this option you must give the minimum number of files when
                        calling this validator the first time; otherwise you will get an error in
                        return.
                    </para>
                </note>

                <para>
                    With this option you can define the minimum number of files you expect to
                    receive.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>max</code>: Sets the maximum number of files to transfer.
                </para>

                <para>
                    With this option you can limit the number of files which are accepted but also
                    detect a possible attack when more files are given than defined in your form.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            If you initiate this validator with a string or integer, the value will be used as
            <code>max</code>. Or you can also use the methods <methodname>setMin()</methodname> and
            <methodname>setMax()</methodname> to set both options afterwards and
            <methodname>getMin()</methodname> and <methodname>getMax()</methodname> to retrieve
            the actual set values.
        </para>

        <example id="zend.file.transfer.validators.count.example">
            <title>Using the Count Validator</title>

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

// Limit the amount of files to maximum 2
$upload->addValidator('Count', false, 2);

// Limit the amount of files to maximum 5 and minimum 1 file
$upload->addValidator('Count', false, array('min' =>1, 'max' => 5));
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator stores the number of checked files internally. The file
                which exceeds the maximum will be returned as error.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.crc32">
        <title>Crc32 Validator</title>

        <para>
            The <code>Crc32</code> validator checks the content of a transferred file by hashing it.
            This validator uses the hash extension from <acronym>PHP</acronym> with the crc32 algorithm.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key or use a numeric array. The values will be used
                    as hash to validate against.
                </para>

                <para>
                    You can set multiple hashes by using different keys. Each will be checked and
                    the validation will fail only if all values fail.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.validators.crc32.example">
            <title>Using the Crc32 Validator</title>

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

// Checks whether the content of the uploaded file has the given hash
$upload->addValidator('Crc32', false, '3b3652f');

// Limits this validator to two different hashes
$upload->addValidator('Crc32', false, array('3b3652f', 'e612b69'));
]]></programlisting>
        </example>
    </sect2>

    <sect2 id="zend.file.transfer.validators.excludeextension">
        <title>ExcludeExtension Validator</title>

        <para>
            The <code>ExcludeExtension</code> validator checks the file extension of the specified
            files. It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key or use a numeric array. The values will be used
                    to check whether the given file does not use this file extension.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>case</code>: Sets a boolean indicating whether validation should be
                    case-sensitive. The default is not case sensitive. Note that this key can be
                    applied to for all available extensions.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple extensions, either as a comma-delimited string, or as
            an array. You may also use the methods <methodname>setExtension()</methodname>,
            <methodname>addExtension()</methodname>, and <methodname>getExtension()</methodname>
            to set and retrieve extensions.
        </para>

        <para>
            In some cases it is useful to match in a case-sensitive fashion. So the constructor
            allows a second parameter called <varname>$case</varname> which, if set to true,
            validates the extension by comparing it with the specified values in a case-sensitive
            fashion.
        </para>

        <example id="zend.file.transfer.validators.excludeextension.example">
            <title>Using the ExcludeExtension Validator</title>

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

// Do not allow files with extension php or exe
$upload->addValidator('ExcludeExtension', false, 'php,exe');

// Do not allow files with extension php or exe, but use array notation
$upload->addValidator('ExcludeExtension', false, array('php', 'exe'));

// Check in a case-sensitive fashion
$upload->addValidator('ExcludeExtension',
                      false,
                      array('php', 'exe', 'case' => true));
$upload->addValidator('ExcludeExtension',
                      false,
                      array('php', 'exe', 'case' => true));
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator only checks the file extension. It does not check the
                file's <acronym>MIME</acronym> type.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.excludemimetype">
        <title>ExcludeMimeType Validator</title>

        <para>
            The <code>ExcludeMimeType</code> validator checks the <acronym>MIME</acronym> type of
            transferred files. It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key individually or use a numeric array. Sets the
                    <acronym>MIME</acronym> type to validate against.
                </para>

                <para>
                    With this option you can define the <acronym>MIME</acronym> type of files that
                    are not to be accepted.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>headerCheck</code>: If set to <constant>TRUE</constant> this option will
                    check the <acronym>HTTP</acronym> Information for the file type when the
                    <emphasis>fileInfo</emphasis> or <emphasis>mimeMagic</emphasis> extensions can
                    not be found. The default value for this option is <constant>FALSE</constant>.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple <acronym>MIME</acronym> types, either as a comma-delimited string, or as
            an array. You may also use the methods <methodname>setMimeType()</methodname>,
            <methodname>addMimeType()</methodname>, and <methodname>getMimeType()</methodname> to
            set and retrieve the <acronym>MIME</acronym> types.
        </para>

        <example id="zend.file.transfer.validators.excludemimetype.example">
            <title>Using the ExcludeMimeType Validator</title>

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

// Does not allow MIME type of gif images for all files
$upload->addValidator('ExcludeMimeType', false, 'image/gif');

// Does not allow MIME type of gif and jpg images for all given files
$upload->addValidator('ExcludeMimeType', false, array('image/gif',
                                                      'image/jpeg');

// Does not allow MIME type of the group images for all given files
$upload->addValidator('ExcludeMimeType', false, 'image');
]]></programlisting>
        </example>

        <para>
            The above example shows that it is also possible to disallow groups of <acronym>MIME</acronym> types.
            For example, to disallow all images, just use 'image' as the <acronym>MIME</acronym> type. This can be used
            for all groups of <acronym>MIME</acronym> types like 'image', 'audio', 'video', 'text', etc.
        </para>

        <note>
            <para>
                Note that disallowing groups of <acronym>MIME</acronym> types will disallow all members of this group
                even if this is not intentional. When you disallow 'image' you will disallow all
                types of images like 'image/jpeg' or 'image/vasa'. When you are not sure if you want
                to disallow all types, you should disallow only specific <acronym>MIME</acronym> types instead of
                complete groups.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.exists">
        <title>Exists Validator</title>

        <para>
            The <code>Exists</code> validator checks for the existence of specified files. It
            supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key or use a numeric array to check if the specific
                    file exists in the given directory.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple directories, either as a comma-delimited string, or as
            an array. You may also use the methods <methodname>setDirectory()</methodname>,
            <methodname>addDirectory()</methodname>, and <methodname>getDirectory()</methodname>
            to set and retrieve directories.
        </para>

        <example id="zend.file.transfer.validators.exists.example">
            <title>Using the Exists Validator</title>

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

// Add the temp directory to check for
$upload->addValidator('Exists', false, '\temp');

// Add two directories using the array notation
$upload->addValidator('Exists',
                      false,
                      array('\home\images', '\home\uploads'));
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator checks whether the specified file exists in all of the
                given directories. The validation will fail if the file does not exist in any of the
                given directories.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.extension">
        <title>Extension Validator</title>

        <para>
            The <code>Extension</code> validator checks the file extension of the specified files.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key or use a numeric array to check whether the
                    specified file has this file extension.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>case</code>: Sets whether validation should be done in a case-sensitive
                    fashion. The default is no case sensitivity. Note the this key is used for all
                    given extensions.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple extensions, either as a comma-delimited string, or as an
            array. You may also use the methods <methodname>setExtension()</methodname>,
            <methodname>addExtension()</methodname>, and <methodname>getExtension()</methodname> to
            set and retrieve extension values.
        </para>

        <para>
            In some cases it is useful to test in a case-sensitive fashion. Therefore the
            constructor takes a second parameter <varname>$case</varname>, which, if set to true,
            will validate the extension in a case-sensitive fashion.
        </para>

        <example id="zend.file.transfer.validators.extension.example">
            <title>Using the Extension Validator</title>

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

// Limit the extensions to jpg and png files
$upload->addValidator('Extension', false, 'jpg,png');

// Limit the extensions to jpg and png files but use array notation
$upload->addValidator('Extension', false, array('jpg', 'png'));

// Check case sensitive
$upload->addValidator('Extension', false, array('mo', 'png', 'case' => true));
if (!$upload->isValid('C:\temp\myfile.MO')) {
    print 'Not valid because MO and mo do not match with case sensitivity;
}
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator only checks the file extension. It does not check the
                file's <acronym>MIME</acronym> type.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.filessize">
        <title>FilesSize Validator</title>

        <para>
            The <code>FilesSize</code> validator checks for the aggregate size of all transferred
            files. It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>min</code>: Sets the minimum aggregate file size.
                    This option defines the minimum aggregate file size to be transferred.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>max</code>: Sets the maximum aggregate file size.
                </para>

                <para>
                    This option limits the aggregate file size of all transferred files, but not the
                    file size of individual files.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>bytestring</code>: Defines whether a failure is to return a user-friendly
                    number or the plain file size.
                </para>

                <para>
                    This option defines whether the user sees '10864' or '10MB'. The default value
                    is true, so '10MB' is returned if you did not specify otherwise.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            You can initialize this validator with a string, which will then be used to set the
            <code>max</code> option. You can also use the methods <methodname>setMin()</methodname>
            and <methodname>setMax()</methodname> to set both options after construction, along with
            <methodname>getMin()</methodname> and <methodname>getMax()</methodname> to retrieve the
            values that have been set previously.
        </para>

        <para>
            The size itself is also accepted in SI notation as handled by most operating systems.
            That is, instead of specifying <emphasis>20000 bytes</emphasis>,
            <emphasis>20kB</emphasis> may be given. All file sizes are converted using 1024 as the
            base value. The following Units are accepted: <code>kB</code>, <code>MB</code>,
            <code>GB</code>, <code>TB</code>, <code>PB</code> and <code>EB</code>. Note that 1kB is
            equal to 1024 bytes, 1MB is equal to 1024kB, and so on.
        </para>

        <example id="zend.file.transfer.validators.filessize.example">
            <title>Using the FilesSize Validator</title>

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

// Limit the size of all files to be uploaded to 40000 bytes
$upload->addValidator('FilesSize', false, 40000);

// Limit the size of all files to be uploaded to maximum 4MB and mimimum 10kB
$upload->addValidator('FilesSize',
                      false,
                      array('min' => '10kB', 'max' => '4MB'));

// As before, but returns the plain file size instead of a user-friendly string
$upload->addValidator('FilesSize',
                      false,
                      array('min' => '10kB',
                            'max' => '4MB',
                            'bytestring' => false));
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator internally stores the file size of checked files. The file
                which exceeds the size will be returned as an error.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.imagesize">
        <title>ImageSize Validator</title>

        <para>
            The <code>ImageSize</code> validator checks the size of image files.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>minheight</code>: Sets the minimum image height.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>maxheight</code>: Sets the maximum image height.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>minwidth</code>: Sets the minimum image width.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>maxwidth</code>: Sets the maximum image width.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            The methods <methodname>setImageMin()</methodname> and
            <methodname>setImageMax()</methodname> also set both minimum and maximum values, while
            the methods <methodname>getMin()</methodname> and <methodname>getMax()</methodname>
            return the currently set values.
        </para>

        <para>
            For your convenience there are also the <methodname>setImageWidth()</methodname> and
            <methodname>setImageHeight()</methodname> methods, which set the minimum and maximum
            height and width of the image file. They, too, have corresponding
            <methodname>getImageWidth()</methodname> and <methodname>getImageHeight()</methodname>
            methods to retrieve the currently set values.
        </para>

        <para>
            To bypass validation of a particular dimension, the relevent option simply should not be
            set.
        </para>

        <example id="zend.file.transfer.validators.imagesize.example">
            <title>Using the ImageSize Validator</title>

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

// Limit the size of a image to a height of 100-200 and a width of
// 40-80 pixel
$upload->addValidator('ImageSize', false,
                      array('minwidth' => 40,
                            'maxwidth' => 80,
                            'minheight' => 100,
                            'maxheight' => 200)
                      );

// Reset the width for validation
$upload->setImageWidth(array('minwidth' => 20, 'maxwidth' => 200));
]]></programlisting>
        </example>
    </sect2>

    <sect2 id="zend.file.transfer.validators.iscompressed">
        <title>IsCompressed Validator</title>

        <para>
            The <code>IsCompressed</code> validator checks if a transferred file is a compressed
            archive, such as zip or arc. This validator is based on the <code>MimeType</code>
            validator and supports the same methods and options. You may also limit this validator
            to particular compression types with the methods described there.
        </para>

        <example id="zend.file.transfer.validators.iscompressed.example">
            <title>Using the IsCompressed Validator</title>

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

// Checks is the uploaded file is a compressed archive
$upload->addValidator('IsCompressed', false);

// Limits this validator to zip files only
$upload->addValidator('IsCompressed', false, array('application/zip'));

// Limits this validator to zip files only using simpler notation
$upload->addValidator('IsCompressed', false, 'zip');
]]></programlisting>
        </example>

        <note>
            <para>
                Note that there is no check if you set a <acronym>MIME</acronym> type that is not a
                archive. For example, it would be possible to define gif files to be accepted by
                this validator. Using the 'MimeType' validator for files which are not archived will
                result in more readable code.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.isimage">
        <title>IsImage Validator</title>

        <para>
            The <code>IsImage</code> validator checks if a transferred file is a image file, such as
            gif or jpeg. This validator is based on the <code>MimeType</code> validator and supports
            the same methods and options. You can limit this validator to particular image types
            with the methods described there.
        </para>

        <example id="zend.file.transfer.validators.isimage.example">
            <title>Using the IsImage Validator</title>

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

// Checks whether the uploaded file is a image file
$upload->addValidator('IsImage', false);

// Limits this validator to gif files only
$upload->addValidator('IsImage', false, array('application/gif'));

// Limits this validator to jpeg files only using a simpler notation
$upload->addValidator('IsImage', false, 'jpeg');
]]></programlisting>
        </example>

        <note>
            <para>
                Note that there is no check if you set a <acronym>MIME</acronym> type that is not an
                image. For example, it would be possible to define zip files to be accepted by this
                validator. Using the 'MimeType' validator for files which are not images will result
                in more readable code.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.hash">
        <title>Hash Validator</title>

        <para>
            The <code>Hash</code> validator checks the content of a transferred file by hashing it.
            This validator uses the hash extension from <acronym>PHP</acronym>. It supports the
            following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Takes any key or use a numeric array. Sets the hash to validate
                    against.
                </para>

                <para>
                    You can set multiple hashes by passing them as an array. Each file is checked,
                    and the validation will fail only if all files fail validation.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>algorithm</code>: Sets the algorithm to use for hashing the content.
                </para>

                <para>
                    You can set multiple algorithm by calling the <methodname>addHash()</methodname>
                    method multiple times.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.validators.hash.example">
            <title>Using the Hash Validator</title>

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

// Checks if the content of the uploaded file contains the given hash
$upload->addValidator('Hash', false, '3b3652f');

// Limits this validator to two different hashes
$upload->addValidator('Hash', false, array('3b3652f', 'e612b69'));

// Sets a different algorithm to check against
$upload->addValidator('Hash',
                      false,
                      array('315b3cd8273d44912a7',
                            'algorithm' => 'md5'));
]]></programlisting>
        </example>

        <note>
            <para>
                This validator supports about 34 different hash algorithms. The most common include
                'crc32', 'md5' and 'sha1'. A comprehesive list of supports hash algorithms can be
                found at the <ulink url="http://php.net/hash_algos">hash_algos method</ulink> on the
                <ulink url="http://php.net">php.net site</ulink>.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.md5">
        <title>Md5 Validator</title>

        <para>
            The <code>Md5</code> validator checks the content of a transferred file by hashing it.
            This validator uses the hash extension for <acronym>PHP</acronym> with the md5 algorithm.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Takes any key or use a numeric array.
                </para>

                <para>
                    You can set multiple hashes by passing them as an array. Each file is checked,
                    and the validation will fail only if all files fail validation.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.validators.md5.example">
            <title>Using the Md5 Validator</title>

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

// Checks if the content of the uploaded file has the given hash
$upload->addValidator('Md5', false, '3b3652f336522365223');

// Limits this validator to two different hashes
$upload->addValidator('Md5',
                      false,
                      array('3b3652f336522365223',
                            'eb3365f3365ddc65365'));
]]></programlisting>
        </example>
    </sect2>

    <sect2 id="zend.file.transfer.validators.mimetype">
        <title>MimeType Validator</title>

        <para>
            The <code>MimeType</code> validator checks the <acronym>MIME</acronym> type of transferred files.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Sets any key or use a numeric array. Sets the <acronym>MIME</acronym> type to
                    validate against.
                </para>

                <para>
                    Defines the <acronym>MIME</acronym> type of files to be accepted.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>headerCheck</code>: If set to <constant>TRUE</constant> this option will
                    check the <acronym>HTTP</acronym> Information for the file type when the
                    <emphasis>fileInfo</emphasis> or <emphasis>mimeMagic</emphasis> extensions can
                    not be found. The default value for this option is <constant>FALSE</constant>.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>magicfile</code>: The magicfile to be used.
                </para>

                <para>
                    With this option you can define which magicfile to use. When it's not set or
                    empty, the MAGIC constant will be used instead. This option is available since
                    Zend Framework 1.7.1.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple <acronym>MIME</acronym> type, either as a
            comma-delimited string, or as an array. You may also use the methods
            <methodname>setMimeType()</methodname>, <methodname>addMimeType()</methodname>, and
            <methodname>getMimeType()</methodname> to set and retrieve <acronym>MIME</acronym>
            type.
        </para>

        <para>
            You can also set the magicfile which shall be used by fileinfo with the 'magicfile'
            option. Additionally there are convenient <methodname>setMagicFile()</methodname> and
            <methodname>getMagicFile()</methodname> methods which allow later setting and retrieving
            of the magicfile parameter. This methods are available since Zend Framework 1.7.1.
        </para>

        <example id="zend.file.transfer.validators.mimetype.example">
            <title>Using the MimeType Validator</title>

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

// Limit the MIME type of all given files to gif images
$upload->addValidator('MimeType', false, 'image/gif');

// Limit the MIME type of all given files to gif and jpeg images
$upload->addValidator('MimeType', false, array('image/gif', 'image/jpeg');

// Limit the MIME type of all given files to the group images
$upload->addValidator('MimeType', false, 'image');

// Use a different magicfile
$upload->addValidator('MimeType',
                      false,
                      array('image',
                            'magicfile' => '/path/to/magicfile.mgx'));
]]></programlisting>
        </example>

        <para>
            The above example shows that it is also possible to limit the accepted
            <acronym>MIME</acronym> type to a group of <acronym>MIME</acronym> types. To allow all
            images just use 'image' as <acronym>MIME</acronym> type. This can be used for all groups
            of <acronym>MIME</acronym> types like 'image', 'audio', 'video', 'text, and so on.
        </para>

        <note>
            <para>
                Note that allowing groups of <acronym>MIME</acronym> types will accept all members
                of this group even if your application does not support them. When you allow 'image'
                you will also get 'image/xpixmap' or 'image/vasa' which could be problematic. When
                you are not sure if your application supports all types you should better allow only
                defined <acronym>MIME</acronym> types instead of the complete group.
            </para>
        </note>

        <note>
            <para>
                This component will use the <code>fileinfo</code> extension if it is available. If
                it's not, it will degrade to the <code>mime_content_type</code> function. And if the
                function call fails it will use the <acronym>MIME</acronym> type which is given by
                <acronym>HTTP</acronym>.
            </para>

            <para>
                You should be aware of possible security problems when you have whether
                <code>fileinfo</code> nor <code>mime_content_type</code> available. The
                <acronym>MIME</acronym> type given by <acronym>HTTP</acronym> is not secure and can
                be easily manipulated.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.notexists">
        <title>NotExists Validator</title>

        <para>
            The <code>NotExists</code> validator checks for the existence of the provided files. It
            supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Set any key or use a numeric array. Checks whether the file
                    exists in the given directory.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            This validator accepts multiple directories either as a comma-delimited string, or as an
            array. You may also use the methods <methodname>setDirectory()</methodname>,
            <methodname>addDirectory()</methodname>, and <methodname>getDirectory()</methodname> to
            set and retrieve directories.
        </para>

        <example id="zend.file.transfer.validators.notexists.example">
            <title>Using the NotExists Validator</title>

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

// Add the temp directory to check
$upload->addValidator('NotExists', false, '\temp');

// Add two directories using the array notation
$upload->addValidator('NotExists', false,
                      array('\home\images',
                            '\home\uploads')
                     );
]]></programlisting>

        </example>
        <note>
            <para>
                Note that this validator checks if the file does not exist in all of the provided
                directories. The validation will fail if the file does exist in any of the given
                directories.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.file.transfer.validators.sha1">
        <title>Sha1 Validator</title>

        <para>
            The <code>Sha1</code> validator checks the content of a transferred file by hashing it.
            This validator uses the hash extension for <acronym>PHP</acronym> with the sha1 algorithm.
            It supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>*</code>: Takes any key or use a numeric array.
                </para>

                <para>
                    You can set multiple hashes by passing them as an array. Each file is checked,
                    and the validation will fail only if all files fail validation.
                </para>
            </listitem>
        </itemizedlist>

        <example id="zend.file.transfer.validators.sha1.example">
            <title>Using the sha1 Validator</title>

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

// Checks if the content of the uploaded file has the given hash
$upload->addValidator('sha1', false, '3b3652f336522365223');

// Limits this validator to two different hashes
$upload->addValidator('Sha1',
                      false, array('3b3652f336522365223',
                                   'eb3365f3365ddc65365'));
]]></programlisting>
        </example>
    </sect2>

    <sect2 id="zend.file.transfer.validators.size">
        <title>Size Validator</title>

        <para>
            The <code>Size</code> validator checks for the size of a single file. It
            supports the following options:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>min</code>: Sets the minimum file size.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>max</code>: Sets the maximum file size.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>bytestring</code>: Defines whether a failure is returned with a
                    user-friendly number, or with the plain file size.
                </para>

                <para>
                    With this option you can define if the user gets '10864' or '10MB'. Default
                    value is true which returns '10MB'.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            You can initialize this validator with a string, which will then be used to set the
            <code>max</code> option. You can also use the methods <methodname>setMin()</methodname>
            and <methodname>setMax()</methodname> to set both options after construction, along with
            <methodname>getMin()</methodname> and <methodname>getMax()</methodname> to retrieve the
            values that have been set previously.
        </para>

        <para>
            The size itself is also accepted in SI notation as handled by most operating systems.
            That is, instead of specifying <emphasis>20000 bytes</emphasis>,
            <emphasis>20kB</emphasis> may be given. All file sizes are converted using 1024 as the
            base value. The following Units are accepted: <code>kB</code>, <code>MB</code>,
            <code>GB</code>, <code>TB</code>, <code>PB</code> and <code>EB</code>. Note that 1kB is
            equal to 1024 bytes, 1MB is equal to 1024kB, and so on.
        </para>

        <example id="zend.file.transfer.validators.size.example">
            <title>Using the Size Validator</title>

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

// Limit the size of a file to 40000 bytes
$upload->addValidator('Size', false, 40000);

// Limit the size a given file to maximum 4MB and mimimum 10kB
// Also returns the plain number in case of an error
// instead of a user-friendly number
$upload->addValidator('Size',
                      false,
                      array('min' => '10kB',
                            'max' => '4MB',
                            'bytestring' => false));
]]></programlisting>
        </example>
    </sect2>

    <sect2 id="zend.file.transfer.validators.wordcount">
        <title>WordCount Validator</title>

        <para>
            The <code>WordCount</code> validator checks for the number of words within provided
            files. It supports the following option keys:
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <code>min</code>: Sets the minimum number of words to be found.
                </para>
            </listitem>

            <listitem>
                <para>
                    <code>max</code>: Sets the maximum number of words to be found.
                </para>
            </listitem>
        </itemizedlist>

        <para>
            If you initiate this validator with a string or integer, the value will be used as
            <code>max</code>. Or you can also use the methods <methodname>setMin()</methodname> and
            <methodname>setMax()</methodname> to set both options afterwards and
            <methodname>getMin()</methodname> and <methodname>getMax()</methodname> to retrieve the
            actual set values.
        </para>

        <example id="zend.file.transfer.validators.wordcount.example">
            <title>Using the WordCount Validator</title>

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

// Limit the amount of words within files to maximum 2000
$upload->addValidator('WordCount', false, 2000);

// Limit the amount of words within files to maximum 5000 and minimum 1000 words
$upload->addValidator('WordCount', false, array('min' => 1000, 'max' => 5000));
]]></programlisting>

        </example>
    </sect2>
</sect1>
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