Add Zend_Media_Id3v2 class proposal

git-svn-id: http://php-reader.googlecode.com/svn/branches/zend@153 51a70ab9-7547-0410-9469-37e369ee0574

src/Zend/Media/Id3/Frame/Link.php

@@ -0,0 +1,188 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Media
+ * @subpackage ID3
+ * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com) 
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id$
+ */
+
+/**#@+ @ignore */
+require_once 'Zend/Media/Id3/Frame.php';
+/**#@-*/
+
+/**
+ * The <i>Linked information</i> frame is used to keep information duplication
+ * as low as possible by linking information from another ID3v2 tag that might
+ * reside in another audio file or alone in a binary file. It is recommended
+ * that this method is only used when the files are stored on a CD-ROM or other
+ * circumstances when the risk of file separation is low.
+ *
+ * Data should be retrieved from the first tag found in the file to which this
+ * link points. There may be more than one LINK frame in a tag, but only one
+ * with the same contents.
+ *
+ * A linked frame is to be considered as part of the tag and has the same
+ * restrictions as if it was a physical part of the tag (i.e. only one
+ * {@link Zend_Media_Id3_Frame_Rvrb RVRB} frame allowed, whether it's linked or
+ * not).
+ *
+ * Frames that may be linked and need no additional data are
+ * {@link Zend_Media_Id3_Frame_Aspi ASPI},
+ * {@link Zend_Media_Id3_Frame_Etco ETCO},
+ * {@link Zend_Media_Id3_Frame_Equ2 EQU2},
+ * {@link Zend_Media_Id3_Frame_Mcdi MCDI},
+ * {@link Zend_Media_Id3_Frame_Mllt MLLT},
+ * {@link Zend_Media_Id3_Frame_Owne OWNE},
+ * {@link Zend_Media_Id3_Frame_Rva2 RVA2},
+ * {@link Zend_Media_Id3_Frame_Rvrb RVRB},
+ * {@link Zend_Media_Id3_Frame_Sytc SYTC}, the text information frames (ie
+ * frames descendats of {@link Zend_Media_Id3_TextFrame}) and the URL
+ * link frames (ie frames descendants of
+ * {@link Zend_Media_Id3_LinkFrame}).
+ *
+ * The {@link Zend_Media_Id3_Frame_Aenc AENC},
+ * {@link Zend_Media_Id3_Frame_Apic APIC},
+ * {@link Zend_Media_Id3_Frame_Geob GEOB}
+ * and {@link Zend_Media_Id3_Frame_Txxx TXXX} frames may be linked with the
+ * content descriptor as additional ID data.
+ *
+ * The {@link Zend_Media_Id3_Frame_User USER} frame may be linked with the
+ * language field as additional ID data.
+ *
+ * The {@link Zend_Media_Id3_Frame_Priv PRIV} frame may be linked with the owner
+ * identifier as additional ID data.
+ *
+ * The {@link Zend_Media_Id3_Frame_Comm COMM},
+ * {@link Zend_Media_Id3_Frame_Sylt SYLT} and
+ * {@link Zend_Media_Id3_Frame_Uslt USLT} frames may be linked with three bytes
+ * of language descriptor directly followed by a content descriptor as
+ * additional ID data.
+ *
+ * @category   Zend
+ * @package    Zend_Media
+ * @subpackage ID3
+ * @author     Sven Vollbehr <sven@vollbehr.eu>
+ * @author     Ryan Butterfield <buttza@gmail.com>
+ * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com) 
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id$
+ */
+final class Zend_Media_Id3_Frame_Link extends Zend_Media_Id3_Frame
+{
+    /** @var string */
+    private $_target;
+
+    /** @var string */
+    private $_url;
+
+    /** @var string */
+    private $_qualifier;
+
+    /**
+     * Constructs the class with given parameters and parses object related
+     * data.
+     *
+     * @param Zend_Io_Reader $reader The reader object.
+     * @param Array $options The options array.
+     */
+    public function __construct($reader = null, &$options = array())
+    {
+        parent::__construct($reader, $options);
+
+        if ($this->_reader === null) {
+            return;
+        }
+
+        $this->_target = $this->_reader->read(4);
+        list($this->_url, $this->_qualifier) =
+            $this->_explodeString8
+                ($this->_reader->read($this->_reader->getSize()), 2);
+    }
+
+    /**
+     * Returns the target tag identifier.
+     *
+     * @return string
+     */
+    public function getTarget() 
+    {
+        return $this->_target; 
+    }
+
+    /**
+     * Sets the target tag identifier.
+     *
+     * @param string $target The target tag identifier.
+     */
+    public function setTarget($target) 
+    {
+        $this->_target = $target; 
+    }
+
+    /**
+     * Returns the target tag URL.
+     *
+     * @return string
+     */
+    public function getUrl() 
+    {
+        return $this->_url; 
+    }
+
+    /**
+     * Sets the target tag URL.
+     *
+     * @param string $url The target URL.
+     */
+    public function setUrl($url) 
+    {
+        $this->_url = $url; 
+    }
+
+    /**
+     * Returns the additional data to identify further the tag.
+     *
+     * @return string
+     */
+    public function getQualifier() 
+    {
+        return $this->_qualifier; 
+    }
+
+    /**
+     * Sets the additional data to be used in tag identification.
+     *
+     * @param string $identifier The qualifier.
+     */
+    public function setQualifier($qualifier)
+    {
+        $this->_qualifier = $qualifier;
+    }
+
+    /**
+     * Writes the frame raw data without the header.
+     *
+     * @param Zend_Io_Writer $writer The writer object.
+     * @return void
+     */
+    protected function _writeFrame($writer)
+    {
+        $writer->writeString8(substr($this->_target, 0, 4), 4)
+               ->writeString8($this->_url, 1)
+               ->writeString8($this->_qualifier);
+    }
+}