thumbnail generator for epubs

1 files changed, 536 insertions, 0 deletions

diff --git a/library/epub-meta/epub.php b/library/epub-meta/epub.php
new file mode 100644
index 000000000..6895a6797
--- /dev/null
+++ b/library/epub-meta/epub.php
@@ -0,0 +1,536 @@
+<?php
+/**
+ * PHP EPub Meta library
+ *
+ * @author Andreas Gohr <andi@splitbrain.org>
+ */
+class EPub {
+    public $xml; //FIXME change to protected, later
+    protected $xpath;
+    protected $file;
+    protected $meta;
+    protected $namespaces;
+    protected $imagetoadd='';
+
+    /**
+     * Constructor
+     *
+     * @param string $file path to epub file to work on
+     * @throws Exception if metadata could not be loaded
+     */
+    public function __construct($file){
+        // open file
+        $this->file = $file;
+        $zip = new ZipArchive();
+        if(!@$zip->open($this->file)){
+            throw new Exception('Failed to read epub file');
+        }
+
+        // read container data
+        $data = $zip->getFromName('META-INF/container.xml');
+        if($data == false){
+            throw new Exception('Failed to access epub container data');
+        }
+        $xml = new DOMDocument();
+        $xml->registerNodeClass('DOMElement','EPubDOMElement');
+        $xml->loadXML($data);
+        $xpath = new EPubDOMXPath($xml);
+        $nodes = $xpath->query('//n:rootfiles/n:rootfile[@media-type="application/oebps-package+xml"]');
+        $this->meta = $nodes->item(0)->attr('full-path');
+
+        // load metadata
+        $data = $zip->getFromName($this->meta);
+        if(!$data){
+            throw new Exception('Failed to access epub metadata');
+        }
+        $this->xml =  new DOMDocument();
+        $this->xml->registerNodeClass('DOMElement','EPubDOMElement');
+        $this->xml->loadXML($data);
+        $this->xml->formatOutput = true;
+        $this->xpath = new EPubDOMXPath($this->xml);
+
+        $zip->close();
+    }
+
+    /**
+     * file name getter
+     */
+    public function file(){
+        return $this->file;
+    }
+
+    /**
+     * Writes back all meta data changes
+     */
+    public function save(){
+        $zip = new ZipArchive();
+        $res = @$zip->open($this->file, ZipArchive::CREATE);
+        if($res === false){
+            throw new Exception('Failed to write back metadata');
+        }
+        $zip->addFromString($this->meta,$this->xml->saveXML());
+        // add the cover image
+        if($this->imagetoadd){
+            $path = dirname('/'.$this->meta).'/php-epub-meta-cover.img'; // image path is relative to meta file
+            $path = ltrim($path,'/');
+
+            $zip->addFromString($path,file_get_contents($this->imagetoadd));
+            $this->imagetoadd='';
+        }
+        $zip->close();
+    }
+
+    /**
+     * Get or set the book author(s)
+     *
+     * Authors should be given with a "file-as" and a real name. The file as
+     * is used for sorting in e-readers.
+     *
+     * Example:
+     *
+     * array(
+     *      'Pratchett, Terry'   => 'Terry Pratchett',
+     *      'Simpson, Jacqeline' => 'Jacqueline Simpson',
+     * )
+     *
+     * @params array $authors
+     */
+    public function Authors($authors=false){
+        // set new data
+        if($authors !== false){
+            // Author where given as a comma separated list
+            if(is_string($authors)){
+                if($authors == ''){
+                    $authors = array();
+                }else{
+                    $authors = explode(',',$authors);
+                    $authors = array_map('trim',$authors);
+                }
+            }
+
+            // delete existing nodes
+            $nodes = $this->xpath->query('//opf:metadata/dc:creator[@opf:role="aut"]');
+            foreach($nodes as $node) $node->delete();
+
+            // add new nodes
+            $parent = $this->xpath->query('//opf:metadata')->item(0);
+            foreach($authors as $as => $name){
+                if(is_int($as)) $as = $name; //numeric array given
+                $node = $parent->newChild('dc:creator',$name);
+                $node->attr('opf:role', 'aut');
+                $node->attr('opf:file-as', $as);
+            }
+
+            $this->reparse();
+        }
+
+        // read current data
+        $rolefix = false;
+        $authors = array();
+        $nodes = $this->xpath->query('//opf:metadata/dc:creator[@opf:role="aut"]');
+        if($nodes->length == 0){
+            // no nodes where found, let's try again without role
+            $nodes = $this->xpath->query('//opf:metadata/dc:creator');
+            $rolefix = true;
+        }
+        foreach($nodes as $node){
+            $name = $node->nodeValue;
+            $as   = $node->attr('opf:file-as');
+            if(!$as){
+                $as = $name;
+                $node->attr('opf:file-as',$as);
+            }
+            if($rolefix){
+                $node->attr('opf:role','aut');
+            }
+            $authors[$as] = $name;
+        }
+        return $authors;
+    }
+
+    /**
+     * Set or get the book title
+     *
+     * @param string $title
+     */
+    public function Title($title=false){
+        return $this->getset('dc:title',$title);
+    }
+
+    /**
+     * Set or get the book's language
+     *
+     * @param string $lang
+     */
+    public function Language($lang=false){
+        return $this->getset('dc:language',$lang);
+    }
+
+    /**
+     * Set or get the book' publisher info
+     *
+     * @param string $publisher
+     */
+    public function Publisher($publisher=false){
+        return $this->getset('dc:publisher',$publisher);
+    }
+
+    /**
+     * Set or get the book's copyright info
+     *
+     * @param string $rights
+     */
+    public function Copyright($rights=false){
+        return $this->getset('dc:rights',$rights);
+    }
+
+    /**
+     * Set or get the book's description
+     *
+     * @param string $description
+     */
+    public function Description($description=false){
+        return $this->getset('dc:description',$description);
+    }
+
+    /**
+     * Set or get the book's ISBN number
+     *
+     * @param string $isbn
+     */
+    public function ISBN($isbn=false){
+        return $this->getset('dc:identifier',$isbn,'opf:scheme','ISBN');
+    }
+
+    /**
+     * Set or get the Google Books ID
+     *
+     * @param string $google
+     */
+    public function Google($google=false){
+        return $this->getset('dc:identifier',$google,'opf:scheme','GOOGLE');
+    }
+
+    /**
+     * Set or get the Amazon ID of the book
+     *
+     * @param string $amazon
+     */
+    public function Amazon($amazon=false){
+        return $this->getset('dc:identifier',$amazon,'opf:scheme','AMAZON');
+    }
+
+    /**
+     * Set or get the book's subjects (aka. tags)
+     *
+     * Subject should be given as array, but a comma separated string will also
+     * be accepted.
+     *
+     * @param array $subjects
+     */
+    public function Subjects($subjects=false){
+        // setter
+        if($subjects !== false){
+            if(is_string($subjects)){
+                if($subjects === ''){
+                    $subjects = array();
+                }else{
+                    $subjects = explode(',',$subjects);
+                    $subjects = array_map('trim',$subjects);
+                }
+            }
+
+            // delete previous
+            $nodes = $this->xpath->query('//opf:metadata/dc:subject');
+            foreach($nodes as $node){
+                $node->delete();
+            }
+            // add new ones
+            $parent = $this->xpath->query('//opf:metadata')->item(0);
+            foreach($subjects as $subj){
+                $node = $this->xml->createElement('dc:subject',htmlspecialchars($subj));
+                $node = $parent->appendChild($node);
+            }
+
+            $this->reparse();
+        }
+
+        //getter
+        $subjects = array();
+        $nodes = $this->xpath->query('//opf:metadata/dc:subject');
+        foreach($nodes as $node){
+            $subjects[] =  $node->nodeValue;
+        }
+        return $subjects;
+    }
+
+    /**
+     * Read the cover data
+     *
+     * Returns an associative array with the following keys:
+     *
+     *   mime  - filetype (usually image/jpeg)
+     *   data  - the binary image data
+     *   found - the internal path, or false if no image is set in epub
+     *
+     * When no image is set in the epub file, the binary data for a transparent
+     * GIF pixel is returned.
+     *
+     * When adding a new image this function return no or old data because the
+     * image contents are not in the epub file, yet. The image will be added when
+     * the save() method is called.
+     *
+     * @param  string $path local filesystem path to a new cover image
+     * @param  string $mime mime type of the given file
+     * @return array
+     */
+    public function Cover($path=false, $mime=false){
+        // set cover
+        if($path !== false){
+            // remove current pointer
+            $nodes = $this->xpath->query('//opf:metadata/opf:meta[@name="cover"]');
+            foreach($nodes as $node) $node->delete();
+            // remove previous manifest entries if they where made by us
+            $nodes = $this->xpath->query('//opf:manifest/opf:item[@id="php-epub-meta-cover"]');
+            foreach($nodes as $node) $node->delete();
+
+            if($path){
+                // add pointer
+                $parent = $this->xpath->query('//opf:metadata')->item(0);
+                $node = $parent->newChild('opf:meta');
+                $node->attr('opf:name','cover');
+                $node->attr('opf:content','php-epub-meta-cover');
+
+                // add manifest
+                $parent = $this->xpath->query('//opf:manifest')->item(0);
+                $node = $parent->newChild('opf:item');
+                $node->attr('id','php-epub-meta-cover');
+                $node->attr('opf:href','php-epub-meta-cover.img');
+                $node->attr('opf:media-type',$mime);
+
+                // remember path for save action
+                $this->imagetoadd = $path;
+            }
+
+            $this->reparse();
+        }
+
+        // load cover
+        $nodes = $this->xpath->query('//opf:metadata/opf:meta[@name="cover"]');
+        if(!$nodes->length) return $this->no_cover();
+        $coverid = (String) $nodes->item(0)->attr('opf:content');
+        if(!$coverid) return $this->no_cover();
+
+        $nodes = $this->xpath->query('//opf:manifest/opf:item[@id="'.$coverid.'"]');
+        if(!$nodes->length) return $this->no_cover();
+        $mime = $nodes->item(0)->attr('opf:media-type');
+        $path = $nodes->item(0)->attr('opf:href');
+        $path = dirname('/'.$this->meta).'/'.$path; // image path is relative to meta file
+        $path = ltrim($path,'/');
+
+        $zip = new ZipArchive();
+        if(!@$zip->open($this->file)){
+            throw new Exception('Failed to read epub file');
+        }
+        $data = $zip->getFromName($path);
+
+        return array(
+            'mime'  => $mime,
+            'data'  => $data,
+            'found' => $path
+        );
+    }
+
+    /**
+     * A simple getter/setter for simple meta attributes
+     *
+     * It should only be used for attributes that are expected to be unique
+     *
+     * @param string $item   XML node to set/get
+     * @param string $value  New node value
+     * @param string $att    Attribute name
+     * @param string $aval   Attribute value
+     */
+    protected function getset($item,$value=false,$att=false,$aval=false){
+        // construct xpath
+        $xpath = '//opf:metadata/'.$item;
+        if($att){
+            $xpath .= "[@$att=\"$aval\"]";
+        }
+
+        // set value
+        if($value !== false){
+            $value = htmlspecialchars($value);
+            $nodes = $this->xpath->query($xpath);
+            if($nodes->length == 1 ){
+                if($value === ''){
+                    // the user want's to empty this value -> delete the node
+                    $nodes->item(0)->delete();
+                }else{
+                    // replace value
+                    $nodes->item(0)->nodeValue = $value;
+                }
+            }else{
+                // if there are multiple matching nodes for some reason delete
+                // them. we'll replace them all with our own single one
+                foreach($nodes as $n) $n->delete();
+                // readd them
+                if($value){
+                    $parent = $this->xpath->query('//opf:metadata')->item(0);
+                    $node   = $this->xml->createElement($item,$value);
+                    $node   = $parent->appendChild($node);
+                    if($att) $node->attr($att,$aval);
+                }
+            }
+
+            $this->reparse();
+        }
+
+        // get value
+        $nodes = $this->xpath->query($xpath);
+        if($nodes->length){
+            return $nodes->item(0)->nodeValue;
+        }else{
+            return '';
+        }
+    }
+
+    /**
+     * Return a not found response for Cover()
+     */
+    protected function no_cover(){
+        return array(
+            'data'  => base64_decode('R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAEALAAAAAABAAEAAAIBTAA7'),
+            'mime'  => 'image/gif',
+            'found' => false
+        );
+    }
+
+    /**
+     * Reparse the DOM tree
+     *
+     * I had to rely on this because otherwise xpath failed to find the newly
+     * added nodes
+     */
+    protected function reparse() {
+        $this->xml->loadXML($this->xml->saveXML());
+        $this->xpath = new EPubDOMXPath($this->xml);
+    }
+}
+
+class EPubDOMXPath extends DOMXPath {
+    public function __construct(DOMDocument $doc){
+        parent::__construct($doc);
+
+        if(is_a($doc->documentElement, 'EPubDOMElement')){
+            foreach($doc->documentElement->namespaces as $ns => $url){
+                $this->registerNamespace($ns,$url);
+            }
+        }
+    }
+}
+
+class EPubDOMElement extends DOMElement {
+    public $namespaces = array(
+        'n'   => 'urn:oasis:names:tc:opendocument:xmlns:container',
+        'opf' => 'http://www.idpf.org/2007/opf',
+        'dc'  => 'http://purl.org/dc/elements/1.1/'
+    );
+
+
+    public function __construct($name, $value='', $namespaceURI=''){
+        list($ns,$name) = $this->splitns($name);
+        $value = htmlspecialchars($value);
+        if(!$namespaceURI && $ns){
+            $namespaceURI = $this->namespaces[$ns];
+        }
+        parent::__construct($name, $value, $namespaceURI);
+    }
+
+
+    /**
+     * Create and append a new child
+     *
+     * Works with our epub namespaces and omits default namespaces
+     */
+    public function newChild($name, $value=''){
+        list($ns,$local) = $this->splitns($name);
+        if($ns){
+            $nsuri = $this->namespaces[$ns];
+            if($this->isDefaultNamespace($nsuri)){
+                $name  = $local;
+                $nsuri = '';
+            }
+        }
+
+        // this doesn't call the construcor: $node = $this->ownerDocument->createElement($name,$value);
+        $node = new EPubDOMElement($name,$value,$nsuri);
+        return $this->appendChild($node);
+    }
+
+    /**
+     * Split given name in namespace prefix and local part
+     *
+     * @param  string $name
+     * @return array  (namespace, name)
+     */
+    public function splitns($name){
+        $list = explode(':',$name,2);
+        if(count($list) < 2) array_unshift($list,'');
+        return $list;
+    }
+
+    /**
+     * Simple EPub namespace aware attribute accessor
+     */
+    public function attr($attr,$value=null){
+        list($ns,$attr) = $this->splitns($attr);
+
+        $nsuri = '';
+        if($ns){
+            $nsuri = $this->namespaces[$ns];
+            if(!$this->namespaceURI){
+                if($this->isDefaultNamespace($nsuri)){
+                    $nsuri = '';
+                }
+            }elseif($this->namespaceURI == $nsuri){
+                 $nsuri = '';
+            }
+        }
+
+        if(!is_null($value)){
+            if($value === false){
+                // delete if false was given
+                if($nsuri){
+                    $this->removeAttributeNS($nsuri,$attr);
+                }else{
+                    $this->removeAttribute($attr);
+                }
+            }else{
+                // modify if value was given
+                if($nsuri){
+                    $this->setAttributeNS($nsuri,$attr,$value);
+                }else{
+                    $this->setAttribute($attr,$value);
+                }
+            }
+        }else{
+            // return value if none was given
+            if($nsuri){
+                return $this->getAttributeNS($nsuri,$attr);
+            }else{
+                return $this->getAttribute($attr);
+            }
+        }
+    }
+
+    /**
+     * Remove this node from the DOM
+     */
+    public function delete(){
+        $this->parentNode->removeChild($this);
+    }
+
+}
+
+