Added epub export function

1 files changed, 1226 insertions, 0 deletions

diff --git a/inc/3rdparty/libraries/PHPePub/EPub.OPF.php b/inc/3rdparty/libraries/PHPePub/EPub.OPF.php
new file mode 100644
index 00000000..803a2108
--- /dev/null
+++ b/inc/3rdparty/libraries/PHPePub/EPub.OPF.php
@@ -0,0 +1,1226 @@
+<?php
+/**
+ * ePub OPF file structure
+ *
+ * @author A. Grandt <php@grandt.com>
+ * @copyright 2009-2014 A. Grandt
+ * @license GNU LGPL, Attribution required for commercial implementations, requested for everything else.
+ * @version 3.20
+ */
+class Opf {
+    const _VERSION = 3.20;
+
+    /* Core Media types.
+     * These types are the only guaranteed mime types any ePub reader must understand.
+    * Any other type muse define a fall back whose fallback chain will end in one of these.
+    */
+    const TYPE_GIF = "image/gif";
+    const TYPE_JPEG = "image/jpeg";
+    const TYPE_PNG = "image/png";
+    const TYPE_SVG = "image/svg+xml";
+    const TYPE_XHTML = "application/xhtml+xml";
+    const TYPE_DTBOOK = "application/x-dtbook+xml";
+    const TYPE_CSS = "text/css";
+    const TYPE_XML = "application/xml";
+    const TYPE_OEB1_DOC = "text/x-oeb1-document"; // Deprecated
+    const TYPE_OEB1_CSS = "text/x-oeb1-css"; // Deprecated
+    const TYPE_NCX = "application/x-dtbncx+xml";
+
+    private $bookVersion = EPub::BOOK_VERSION_EPUB2;
+        private $ident = "BookId";
+
+    public $date = NULL;
+    public $metadata = NULL;
+    public $manifest = NULL;
+    public $spine = NULL;
+    public $guide = NULL;
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct($ident = "BookId", $bookVersion = EPub::BOOK_VERSION_EPUB2) {
+        $this->setIdent($ident);
+        $this->setVersion($bookVersion);
+        $this->metadata = new Metadata();
+        $this->manifest = new Manifest();
+        $this->spine = new Spine();
+        $this->guide = new Guide();
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->bookVersion, $this->ident, $this->date, $this->metadata, $this->manifest, $this->spine, $this->guide);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $ident
+     */
+    function setVersion($bookVersion) {
+        $this->bookVersion = is_string($bookVersion) ? trim($bookVersion) : EPub::BOOK_VERSION_EPUB2;
+    }
+
+        function isEPubVersion2() {
+                return $this->bookVersion === EPub::BOOK_VERSION_EPUB2;
+        }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $ident
+     */
+    function setIdent($ident = "BookId") {
+        $this->ident = is_string($ident) ? trim($ident) : "BookId";
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @return string
+     */
+    function finalize() {
+        $opf = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
+                                . "<package xmlns=\"http://www.idpf.org/2007/opf\" unique-identifier=\"" . $this->ident . "\" version=\"" . $this->bookVersion . "\">\n";
+
+                $opf .= $this->metadata->finalize($this->bookVersion, $this->date);
+        $opf .= $this->manifest->finalize($this->bookVersion);
+        $opf .= $this->spine->finalize();
+
+        if ($this->guide->length() > 0) {
+            $opf .= $this->guide->finalize();
+        }
+
+        return $opf . "</package>\n";
+    }
+
+    // Convenience functions:
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $title
+     * @param string $language
+     * @param string $identifier
+     * @param string $identifierScheme
+     */
+    function initialize($title, $language, $identifier, $identifierScheme) {
+        $this->metadata->addDublinCore(new DublinCore("title", $title));
+        $this->metadata->addDublinCore(new DublinCore("language", $language));
+
+        $dc = new DublinCore("identifier", $identifier);
+        $dc->addAttr("id", $this->ident);
+        $dc->addOpfAttr("scheme", $identifierScheme);
+        $this->metadata->addDublinCore($dc);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $id
+     * @param string $href
+     * @param string $mediaType
+     */
+    function addItem($id, $href, $mediaType, $properties = NULL) {
+        $this->manifest->addItem(new Item($id, $href, $mediaType, $properties));
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $idref
+     * @param bool   $linear
+     */
+    function addItemRef($idref, $linear = TRUE) {
+        $this->spine->addItemref(new Itemref($idref, $linear));
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $type
+     * @param string $title
+     * @param string $href
+     */
+    function addReference($type, $title, $href) {
+        $this->guide->addReference(new Reference($type, $title, $href));
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $value
+     */
+    function addDCMeta($name, $value) {
+        $this->metadata->addDublinCore(new DublinCore($name, $value));
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $content
+     */
+    function addMeta($name, $content) {
+        $this->metadata->addMeta($name, $content);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $fileAs
+     * @param string $role Use the MarcCode constants
+     */
+    function addCreator($name, $fileAs = NULL, $role = NULL) {
+        $dc = new DublinCore(DublinCore::CREATOR, trim($name));
+
+        if ($fileAs !== NULL) {
+            $dc->addOpfAttr("file-as", trim($fileAs));
+        }
+
+        if ($role !== NULL) {
+            $dc->addOpfAttr("role", trim($role));
+        }
+
+        $this->metadata->addDublinCore($dc);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $fileAs
+     * @param string $role Use the MarcCode constants
+     */
+    function addColaborator($name, $fileAs = NULL, $role = NULL) {
+        $dc = new DublinCore(DublinCore::CONTRIBUTOR, trim($name));
+
+        if ($fileAs !== NULL) {
+            $dc->addOpfAttr("file-as", trim($fileAs));
+        }
+
+        if ($role !== NULL) {
+            $dc->addOpfAttr("role", trim($role));
+        }
+
+        $this->metadata->addDublinCore($dc);
+    }
+}
+
+/**
+ * ePub OPF Metadata structures
+ */
+class Metadata {
+    const _VERSION = 3.00;
+
+    private $dc = array();
+    private $meta = array();
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct() {
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->dc, $this->meta);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param DublinCore $dc
+     */
+    function addDublinCore($dc) {
+        if ($dc != NULL && is_object($dc) && get_class($dc) === "DublinCore") {
+            $this->dc[] = $dc;
+        }
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $content
+     */
+    function addMeta($name, $content) {
+        $name = is_string($name) ? trim($name) : NULL;
+        if (isset($name)) {
+            $content = is_string($content) ? trim($content) : NULL;
+        }
+        if (isset($content)) {
+            $this->meta[] = array ($name => $content);
+        }
+    }
+
+        /**
+         *
+         * @param string $bookVersion
+         * @param int    $date
+         * @return string
+         */
+    function finalize($bookVersion = EPub::BOOK_VERSION_EPUB2, $date = NULL) {
+        $metadata = "\t<metadata xmlns:dc=\"http://purl.org/dc/elements/1.1/\"\n";
+                if ($bookVersion === EPub::BOOK_VERSION_EPUB2) {
+                        $metadata .= "\t\txmlns:opf=\"http://www.idpf.org/2007/opf\"\n\t\txmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">\n";
+                } else {
+                        $metadata .= "\t\txmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">\n";
+                        if (!isset($date)) {
+                                $date = time();
+                        }
+                        $metadata .= "\t\t<meta property=\"dcterms:modified\">" . gmdate("Y-m-d\TH:i:s\Z", $date) . "</meta>\n";
+                }
+
+        foreach ($this->dc as $dc) {
+            $metadata .= $dc->finalize($bookVersion);
+        }
+
+        foreach ($this->meta as $data) {
+            list($name, $content) = each($data);
+            $metadata .= "\t\t<meta name=\"" . $name . "\" content=\"" . $content . "\" />\n";
+        }
+
+        return $metadata . "\t</metadata>\n";
+    }
+}
+
+/**
+ * ePub OPF Dublin Core (dc:) Metadata structures
+ */
+class DublinCore {
+    const _VERSION = 3.00;
+
+    const CONTRIBUTOR = "contributor";
+    const COVERAGE = "coverage";
+    const CREATOR = "creator";
+    const DATE = "date";
+    const DESCRIPTION = "description";
+    const FORMAT = "format";
+    const IDENTIFIER = "identifier";
+    const LANGUAGE = "language";
+    const PUBLISHER = "publisher";
+    const RELATION = "relation";
+    const RIGHTS = "rights";
+    const SOURCE = "source";
+    const SUBJECT = "subject";
+    const TITLE = "title";
+    const TYPE = "type";
+
+    private $dcName = NULL;
+    private $dcValue = NULL;
+    private $attr = array();
+    private $opfAttr = array();
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct($name, $value) {
+        $this->setDc($name, $value);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->dcName, $this->dcValue, $this->attr, $this->opfAttr);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $name
+     * @param string $value
+     */
+    function setDc($name, $value) {
+        $this->dcName = is_string($name) ? trim($name) : NULL;
+        if (isset($this->dcName)) {
+            $this->dcValue = isset($value) ? (string)$value : NULL;
+        }
+        if (! isset($this->dcValue)) {
+            $this->dcName = NULL;
+        }
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $attrName
+     * @param string $attrValue
+     */
+    function addAttr($attrName, $attrValue) {
+        $attrName = is_string($attrName) ? trim($attrName) : NULL;
+        if (isset($attrName)) {
+            $attrValue = is_string($attrValue) ? trim($attrValue) : NULL;
+        }
+        if (isset($attrValue)) {
+            $this->attr[$attrName] = $attrValue;
+        }
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $opfAttrName
+     * @param string $opfAttrValue
+     */
+    function addOpfAttr($opfAttrName, $opfAttrValue) {
+        $opfAttrName = is_string($opfAttrName) ? trim($opfAttrName) : NULL;
+        if (isset($opfAttrName)) {
+            $opfAttrValue = is_string($opfAttrValue) ? trim($opfAttrValue) : NULL;
+        }
+        if (isset($opfAttrValue)) {
+            $this->opfAttr[$opfAttrName] = $opfAttrValue;
+        }
+    }
+
+
+        /**
+         *
+         * @param string $bookVersion
+         * @return string
+         */
+    function finalize($bookVersion = EPub::BOOK_VERSION_EPUB2) {
+        $dc = "\t\t<dc:" . $this->dcName;
+
+        if (sizeof($this->attr) > 0) {
+            while (list($name, $content) = each($this->attr)) {
+                $dc .= " " . $name . "=\"" . $content . "\"";
+            }
+        }
+
+        if ($bookVersion === EPub::BOOK_VERSION_EPUB2 && sizeof($this->opfAttr) > 0) {
+            while (list($name, $content) = each($this->opfAttr)) {
+                $dc .= " opf:" . $name . "=\"" . $content . "\"";
+            }
+        }
+
+        return $dc . ">" . $this->dcValue . "</dc:" . $this->dcName . ">\n";
+    }
+}
+
+/**
+ * ePub OPF Manifest structure
+ */
+class Manifest {
+    const _VERSION = 3.00;
+
+    private $items = array();
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct() {
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->items);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param Item $item
+     */
+    function addItem($item) {
+        if ($item != NULL && is_object($item) && get_class($item) === "Item") {
+            $this->items[] = $item;
+        }
+    }
+
+        /**
+         *
+         * @param string $bookVersion
+         * @return string
+         */
+        function finalize($bookVersion = EPub::BOOK_VERSION_EPUB2) {
+        $manifest = "\n\t<manifest>\n";
+        foreach ($this->items as $item) {
+            $manifest .= $item->finalize($bookVersion);
+        }
+        return $manifest . "\t</manifest>\n";
+    }
+}
+
+/**
+ * ePub OPF Item structure
+ */
+class Item {
+    const _VERSION = 3.00;
+
+    private $id = NULL;
+    private $href = NULL;
+    private $mediaType = NULL;
+        private $properties = NULL;
+    private $requiredNamespace = NULL;
+    private $requiredModules = NULL;
+    private $fallback = NULL;
+    private $fallbackStyle = NULL;
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct($id, $href, $mediaType, $properties = NULL) {
+        $this->setId($id);
+        $this->setHref($href);
+        $this->setMediaType($mediaType);
+        $this->setProperties($properties);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->id, $this->href, $this->mediaType);
+        unset ($this->properties, $this->requiredNamespace, $this->requiredModules, $this->fallback, $this->fallbackStyle);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $id
+     */
+    function setId($id) {
+        $this->id = is_string($id) ? trim($id) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $href
+     */
+    function setHref($href) {
+        $this->href = is_string($href) ? trim($href) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $mediaType
+     */
+    function setMediaType($mediaType) {
+        $this->mediaType = is_string($mediaType) ? trim($mediaType) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $properties
+     */
+    function setProperties($properties) {
+        $this->properties = is_string($properties) ? trim($properties) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $requiredNamespace
+     */
+    function setRequiredNamespace($requiredNamespace) {
+        $this->requiredNamespace = is_string($requiredNamespace) ? trim($requiredNamespace) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $requiredModules
+     */
+    function setRequiredModules($requiredModules) {
+        $this->requiredModules = is_string($requiredModules) ? trim($requiredModules) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $fallback
+     */
+    function setfallback($fallback) {
+        $this->fallback = is_string($fallback) ? trim($fallback) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $fallbackStyle
+     */
+    function setFallbackStyle($fallbackStyle) {
+        $this->fallbackStyle = is_string($fallbackStyle) ? trim($fallbackStyle) : NULL;
+    }
+
+        /**
+         *
+         * @param string $bookVersion
+         * @return string
+         */
+    function finalize($bookVersion = EPub::BOOK_VERSION_EPUB2) {
+        $item = "\t\t<item id=\"" . $this->id . "\" href=\"" . $this->href . "\" media-type=\"" . $this->mediaType . "\" ";
+                if ($bookVersion === EPub::BOOK_VERSION_EPUB3 && isset($this->properties)) {
+            $item .= "properties=\"" . $this->properties . "\" ";
+        }
+        if (isset($this->requiredNamespace)) {
+            $item .= "\n\t\t\trequired-namespace=\"" . $this->requiredNamespace . "\" ";
+            if (isset($this->requiredModules)) {
+                $item .= "required-modules=\"" . $this->requiredModules . "\" ";
+            }
+        }
+        if (isset($this->fallback)) {
+            $item .= "\n\t\t\tfallback=\"" . $this->fallback . "\" ";
+        }
+        if (isset($this->fallbackStyle)) {
+            $item .= "\n\t\t\tfallback-style=\"" . $this->fallbackStyle . "\" ";
+        }
+        return $item . "/>\n";
+    }
+}
+
+/**
+ * ePub OPF Spine structure
+ */
+class Spine {
+    const _VERSION = 1.00;
+
+    private $itemrefs = array();
+    private $toc = NULL;
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct($toc = "ncx") {
+        $this->setToc($toc);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->itemrefs, $this->toc);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $toc
+     */
+    function setToc($toc) {
+        $this->toc = is_string($toc) ? trim($toc) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param Itemref $itemref
+     */
+    function addItemref($itemref) {
+        if ($itemref != NULL 
+                                && is_object($itemref) 
+                                && get_class($itemref) === "Itemref" 
+                                && !isset($this->itemrefs[$itemref->getIdref()])) {
+            $this->itemrefs[$itemref->getIdref()] = $itemref;
+        }
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @return string
+     */
+    function finalize() {
+        $spine = "\n\t<spine toc=\"" . $this->toc . "\">\n";
+        foreach ($this->itemrefs as $itemref) {
+            $spine .= $itemref->finalize();
+        }
+        return $spine . "\t</spine>\n";
+    }
+}
+
+/**
+ * ePub OPF ItemRef structure
+ */
+class Itemref {
+    const _VERSION = 3.00;
+
+    private $idref = NULL;
+    private $linear = TRUE;
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct($idref, $linear = TRUE) {
+        $this->setIdref($idref);
+        $this->setLinear($linear);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->idref, $this->linear);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $idref
+     */
+    function setIdref($idref) {
+        $this->idref = is_string($idref) ? trim($idref) : NULL;
+    }
+
+        /**
+     *
+     * Enter description here ...
+     *
+     * @return string $idref
+     */
+    function getIdref() {
+        return $this->idref;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param bool $linear
+     */
+    function setLinear($linear = TRUE) {
+        $this->linear = $linear === TRUE;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @return string
+     */
+    function finalize() {
+        $itemref = "\t\t<itemref idref=\"" . $this->idref . "\"";
+        if ($this->linear == FALSE) {
+            return $itemref .= " linear=\"no\" />\n";
+        }
+        return $itemref . " />\n";
+    }
+}
+
+/**
+ * ePub OPF Guide structure
+ */
+class Guide {
+    const _VERSION = 3.00;
+
+    private $references = array();
+
+    /**
+     * Class constructor.
+     *
+     * @return void
+     */
+    function __construct() {
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->references);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     */
+    function length() {
+        return sizeof($this->references);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param Reference $reference
+     */
+    function addReference($reference) {
+        if ($reference != NULL && is_object($reference) && get_class($reference) === "Reference") {
+            $this->references[] = $reference;
+        }
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @return string
+     */
+    function finalize() {
+        $ref = "";
+        if (sizeof($this->references) > 0) {
+            $ref = "\n\t<guide>\n";
+            foreach ($this->references as $reference) {
+                $ref .= $reference->finalize();
+            }
+            $ref .= "\t</guide>\n";
+        }
+        return $ref;
+    }
+}
+
+/**
+ * Reference constants
+ */
+class Reference {
+    const _VERSION = 1.00;
+
+    /* REFERENCE types are derived from the "Chicago Manual of Style"
+     */
+
+    /** Acknowledgements page */
+    const ACKNOWLEDGEMENTS = "acknowledgements";
+
+    /** Bibliography page */
+    const BIBLIOGRAPHY = "bibliography";
+
+    /** Colophon page */
+    const COLOPHON = "colophon";
+
+    /** Copyright page */
+    const COPYRIGHT_PAGE = "copyright-page";
+
+    /** Dedication */
+    const DEDICATION = "dedication";
+
+    /** Epigraph */
+    const EPIGRAPH = "epigraph";
+
+    /** Foreword */
+    const FOREWORD = "foreword";
+
+    /** Glossary page */
+    const GLOSSARY = "glossary";
+
+    /** back-of-book style index */
+    const INDEX = "index";
+
+    /** List of illustrations */
+    const LIST_OF_ILLUSTRATIONS = "loi";
+
+    /** List of tables */
+    const LIST_OF_TABLES = "lot";
+
+    /** Notes page */
+    const NOTES = "notes";
+
+    /** Preface page */
+    const PREFACE = "preface";
+
+    /** Table of contents */
+    const TABLE_OF_CONTENTS = "toc";
+
+    /** Page with possibly title, author, publisher, and other metadata */
+    const TITLE_PAGE = "titlepage";
+
+    /** First page of the book, ie. first page of the first chapter */
+    const TEXT = "text";
+
+        // ******************
+        // ePub3 constants
+        // ******************
+
+        // Document partitions
+        /** The publications cover(s), jacket information, etc. This is officially in ePub3, but works for ePub 2 as well */
+        const COVER = "cover";
+
+        /** Preliminary material to the content body, such as tables of contents, dedications, etc. */
+        const FRONTMATTER = "frontmatter";
+
+        /** The main (body) content of a document. */
+        const BODYMATTER = "bodymatter";
+
+        /** Ancillary material occurring after the document body, such as indices, appendices, etc. */
+        const BACKMATTER = "backmatter";
+
+
+        private $type = NULL;
+    private $title = NULL;
+    private $href = NULL;
+
+    /**
+     * Class constructor.
+         *
+         * @param string $type
+         * @param string $title
+         * @param string $href
+         */
+    function __construct($type, $title, $href) {
+        $this->setType($type);
+        $this->setTitle($title);
+        $this->setHref($href);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    function __destruct() {
+        unset ($this->type, $this->title, $this->href);
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $type
+     */
+    function setType($type) {
+        $this->type = is_string($type) ? trim($type) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $title
+     */
+    function setTitle($title) {
+        $this->title = is_string($title) ? trim($title) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @param string $href
+     */
+    function setHref($href) {
+        $this->href = is_string($href) ? trim($href) : NULL;
+    }
+
+    /**
+     *
+     * Enter description here ...
+     *
+     * @return string
+     */
+    function finalize() {
+        return "\t\t<reference type=\"" . $this->type . "\" title=\"" . $this->title . "\" href=\"" . $this->href . "\" />\n";
+    }
+}
+
+/**
+ * Common Marc codes.
+ * Ref: http://www.loc.gov/marc/relators/
+ */
+class MarcCode {
+    const _VERSION = 3.00;
+
+    /**
+     * Adapter
+     *
+     * Use for a person who
+     * 1) reworks a musical composition, usually for a different medium, or
+     * 2) rewrites novels or stories for motion pictures or other audiovisual medium.
+     */
+    const ADAPTER = "adp";
+
+    /**
+     * Annotator
+     *
+     * Use for a person who writes manuscript annotations on a printed item.
+     */
+    const ANNOTATOR = "ann";
+
+    /**
+     * Arranger
+     *
+     * Use for a person who transcribes a musical composition, usually for a different
+     *  medium from that of the original; in an arrangement the musical substance remains
+     *  essentially unchanged.
+     */
+    const ARRANGER = "arr";
+
+    /**
+     * Artist
+     *
+     * Use for a person (e.g., a painter) who conceives, and perhaps also implements,
+     *  an original graphic design or work of art, if specific codes (e.g., [egr],
+     *  [etr]) are not desired. For book illustrators, prefer Illustrator [ill].
+     */
+    const ARTIST = "art";
+
+    /**
+     * Associated name
+     *
+     * Use as a general relator for a name associated with or found in an item or
+     *  collection, or which cannot be determined to be that of a Former owner [fmo]
+     *  or other designated relator indicative of provenance.
+     */
+    const ASSOCIATED_NAME = "asn";
+
+    /**
+     * Author
+     *
+     * Use for a person or corporate body chiefly responsible for the intellectual
+     *  or artistic content of a work. This term may also be used when more than one
+     *  person or body bears such responsibility.
+     */
+    const AUTHOR = "aut";
+
+    /**
+     * Author in quotations or text extracts
+     *
+     * Use for a person whose work is largely quoted or extracted in a works to which
+     *  he or she did not contribute directly. Such quotations are found particularly
+     *  in exhibition catalogs, collections of photographs, etc.
+     */
+    const AUTHOR_IN_QUOTES = "aqt";
+
+    /**
+     * Author of afterword, colophon, etc.
+     *
+     * Use for a person or corporate body responsible for an afterword, postface,
+     *  colophon, etc. but who is not the chief author of a work.
+     */
+    const AUTHOR_OF_AFTERWORD = "aft";
+
+    /**
+     * Author of introduction, etc.
+     *
+     * Use for a person or corporate body responsible for an introduction, preface,
+     *  foreword, or other critical matter, but who is not the chief author.
+     */
+    const AUTHOR_OF_INTRO = "aui";
+
+    /**
+     * Bibliographic antecedent
+     *
+     * Use for the author responsible for a work upon which the work represented by
+     *  the catalog record is based. This can be appropriate for adaptations, sequels,
+     *  continuations, indexes, etc.
+     */
+    const BIB_ANTECEDENT = "ant";
+
+    /**
+     * Book producer
+     *
+     * Use for the person or firm responsible for the production of books and other
+     *  print media, if specific codes (e.g., [bkd], [egr], [tyd], [prt]) are not desired.
+     */
+    const BOOK_PRODUCER = "bkp";
+
+    /**
+     * Collaborator
+     *
+     * Use for a person or corporate body that takes a limited part in the elaboration
+     *  of a work of another author or that brings complements (e.g., appendices, notes)
+     *  to the work of another author.
+     */
+    const COLABORATOR = "clb";
+
+    /**
+     * Commentator
+     *
+     * Use for a person who provides interpretation, analysis, or a discussion of the
+     *  subject matter on a recording, motion picture, or other audiovisual medium.
+     *  Compiler [com] Use for a person who produces a work or publication by selecting
+     *  and putting together material from the works of various persons or bodies.
+     */
+    const COMMENTATOR = "cmm";
+
+    /**
+     * Designer
+     *
+     * Use for a person or organization responsible for design if specific codes (e.g.,
+     *  [bkd], [tyd]) are not desired.
+     */
+    const DESIGNER = "dsr";
+
+    /**
+     * Editor
+     *
+     * Use for a person who prepares for publication a work not primarily his/her own,
+     *  such as by elucidating text, adding introductory or other critical matter, or
+     *  technically directing an editorial staff.
+     */
+    const EDITORT = "edt";
+
+    /**
+     * Illustrator
+     *
+     * Use for the person who conceives, and perhaps also implements, a design or
+     *  illustration, usually to accompany a written text.
+     */
+    const ILLUSTRATOR = "ill";
+
+    /**
+     * Lyricist
+     *
+     * Use for the writer of the text of a song.
+     */
+    const LYRICIST = "lyr";
+
+    /**
+     * Metadata contact
+     *
+     * Use for the person or organization primarily responsible for compiling and
+     *  maintaining the original description of a metadata set (e.g., geospatial
+     *  metadata set).
+     */
+    const METADATA_CONTACT = "mdc";
+
+    /**
+     * Musician
+     *
+     * Use for the person who performs music or contributes to the musical content
+     *  of a work when it is not possible or desirable to identify the function more
+     *  precisely.
+     */
+    const MUSICIAN = "mus";
+
+    /**
+     * Narrator
+     *
+     * Use for the speaker who relates the particulars of an act, occurrence, or
+     *  course of events.
+     */
+    const NARRATOR = "nrt";
+
+    /**
+     * Other
+     *
+     * Use for relator codes from other lists which have no equivalent in the MARC
+     *  list or for terms which have not been assigned a code.
+     */
+    const OTHER = "oth";
+
+    /**
+     * Photographer
+     *
+     * Use for the person or organization responsible for taking photographs, whether
+     *  they are used in their original form or as reproductions.
+     */
+    const PHOTOGRAPHER = "pht";
+
+    /**
+     * Printer
+     *
+     * Use for the person or organization who prints texts, whether from type or plates.
+     */
+    const PRINTER = "prt";
+
+    /**
+     * Redactor
+     *
+     * Use for a person who writes or develops the framework for an item without
+     *  being intellectually responsible for its content.
+     */
+    const REDACTOR = "red";
+
+    /**
+     * Reviewer
+     *
+     * Use for a person or corporate body responsible for the review of book, motion
+     *  picture, performance, etc.
+     */
+    const REVIEWER = "rev";
+
+    /**
+     * Sponsor
+     *
+     * Use for the person or agency that issued a contract, or under whose auspices
+     *  a work has been written, printed, published, etc.
+     */
+    const SPONSOR = "spn";
+
+    /**
+     * Thesis advisor
+     *
+     * Use for the person under whose supervision a degree candidate develops and
+     *  presents a thesis, memoir, or text of a dissertation.
+     */
+    const THESIS_ADVISOR = "ths";
+
+    /**
+     * Transcriber
+     *
+     * Use for a person who prepares a handwritten or typewritten copy from original
+     *  material, including from dictated or orally recorded material.
+     */
+    const TRANSCRIBER = "trc";
+
+    /**
+     * Translator
+     *
+     * Use for a person who renders a text from one language into another, or from
+     *  an older form of a language into the modern form.
+     */
+    const TRANSLATOR = "trl";
+}
+?>