Add metadata

ARCHITECTURE.md

@@ -44,7 +44,7 @@ It is structured mainly into:
 
 The Backend itself is divided into multiple parts
 
-- *Content* contains a minimal structure of supported structures by the backend (hence the "frontend" for the IR). It
+- *Structure* contains a minimal structure of supported structures by the backend (hence the "frontend" for the IR). It
   renders content types such as text / images into a stream consumable for PDFs, and creates the catalog structure of
   the PDF.
 - *Catalog* contains the logical structure of a PDF. It is capable of converting this logical structure into a structure

examples/book.php

@@ -11,8 +11,10 @@
 use Famoser\PdfGenerator\Frontend\Layout\Style\FlowDirection;
 use Famoser\PdfGenerator\Frontend\LinearDocument;
 use Famoser\PdfGenerator\Frontend\Resource\Font;
+use Famoser\PdfGenerator\IR\Document\Meta;
 
-$document = new LinearDocument([210, 297], 20);
+$meta = Meta::createMeta('en', 'Cat in the rain', ['Ernest Hemingway']);
+$document = new LinearDocument([210, 297], 20, $meta);
 
 $font = Font::createFromFile('cruft.ttf');
 $normalText = new TextStyle($font, 6.6);

examples/invoice.php

@@ -22,9 +22,11 @@
 use Famoser\PdfGenerator\Frontend\LinearDocument;
 use Famoser\PdfGenerator\Frontend\Resource\Font;
 use Famoser\PdfGenerator\IR\Document\Content\Common\Color;
+use Famoser\PdfGenerator\IR\Document\Meta;
 
 $margin = 15;
-$document = new LinearDocument([210, 297], $margin);
+$meta = Meta::createMeta('en', 'Invoice UZH-ZI-5', ['Florian Moser']);
+$document = new LinearDocument([210, 297], $margin, $meta);
 
 $normalFont = Font::createFromDefault();
 $normalText = new TextStyle($normalFont);

src/Backend/Catalog/Catalog.php

@@ -18,7 +18,7 @@
 
 readonly class Catalog extends BaseStructure
 {
-    public function __construct(private Pages $pages)
+    public function __construct(private Pages $pages, private Metadata $metadata)
     {
     }
 
@@ -32,6 +32,11 @@ public function getPages(): Pages
         return $this->pages;
     }
 
+    public function getMetadata(): Metadata
+    {
+        return $this->metadata;
+    }
+
     public function render(): File
     {
         $file = new File();

src/Backend/Catalog/Content.php

@@ -14,6 +14,7 @@
 use Famoser\PdfGenerator\Backend\Catalog\Base\BaseStructure;
 use Famoser\PdfGenerator\Backend\CatalogVisitor;
 use Famoser\PdfGenerator\Backend\File\Object\Base\BaseObject;
+use Famoser\PdfGenerator\Backend\File\Object\StreamObject;
 
 readonly class Content extends BaseStructure
 {
@@ -26,10 +27,7 @@ public function getContent(): string
         return $this->content;
     }
 
-    /**
-     * @return BaseObject|BaseObject[]
-     */
-    public function accept(CatalogVisitor $visitor): BaseObject|array
+    public function accept(CatalogVisitor $visitor): StreamObject
     {
         return $visitor->visitContent($this);
     }

src/Backend/Catalog/Font.php

@@ -12,6 +12,8 @@
 namespace Famoser\PdfGenerator\Backend\Catalog;
 
 use Famoser\PdfGenerator\Backend\Catalog\Base\BaseIdentifiableStructure;
+use Famoser\PdfGenerator\Backend\CatalogVisitor;
+use Famoser\PdfGenerator\Backend\File\Object\Base\BaseObject;
 
 abstract readonly class Font extends BaseIdentifiableStructure
 {
@@ -21,4 +23,6 @@ public function __construct(string $identifier)
     }
 
     abstract public function encode(string $value): string;
+
+    abstract public function accept(CatalogVisitor $visitor): BaseObject;
 }

src/Backend/Catalog/Font/Type1.php

@@ -14,6 +14,7 @@
 use Famoser\PdfGenerator\Backend\Catalog\Font;
 use Famoser\PdfGenerator\Backend\CatalogVisitor;
 use Famoser\PdfGenerator\Backend\File\Object\Base\BaseObject;
+use Famoser\PdfGenerator\Backend\File\Object\DictionaryObject;
 
 readonly class Type1 extends Font
 {
@@ -49,7 +50,7 @@ public function getEncoding(): string
         return self::ENCODING_WIN_ANSI_ENCODING;
     }
 
-    public function accept(CatalogVisitor $visitor): BaseObject
+    public function accept(CatalogVisitor $visitor): DictionaryObject
     {
         return $visitor->visitType1Font($this);
     }

src/Backend/Catalog/Metadata.php

@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the famoser/pdf-generator project.
+ *
+ * (c) Florian Moser <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Famoser\PdfGenerator\Backend\Catalog;
+
+use Famoser\PdfGenerator\Backend\Catalog\Base\BaseStructure;
+use Famoser\PdfGenerator\Backend\CatalogVisitor;
+use Famoser\PdfGenerator\Backend\File\Object\Base\BaseObject;
+
+readonly class Metadata extends BaseStructure
+{
+    public function __construct(private string $xml, private ?string $title, private ?string $author, private ?string $keywords)
+    {
+    }
+
+    public function getXml(): string
+    {
+        return $this->xml;
+    }
+
+    public function getTitle(): ?string
+    {
+        return $this->title;
+    }
+
+    public function getAuthor(): ?string
+    {
+        return $this->author;
+    }
+
+    public function getKeywords(): ?string
+    {
+        return $this->keywords;
+    }
+
+    public function accept(CatalogVisitor $visitor): BaseObject
+    {
+        return $visitor->visitMetadata($this);
+    }
+}

src/Backend/CatalogVisitor.php

@@ -25,6 +25,7 @@
 class CatalogVisitor
 {
     private ?DictionaryObject $currentPages = null;
+    public const GENERATOR_VERSION = '0.7';
 
     public function __construct(private readonly File $file)
     {
@@ -38,9 +39,17 @@ public function visitCatalog(Catalog\Catalog $structure): BaseObject
         $reference = $structure->getPages()->accept($this);
         $dictionary->addReferenceEntry('Pages', $reference);
 
+        $metadata = $structure->getMetadata()->accept($this);
+        $dictionary->addReferenceEntry('Metadata', $metadata);
+
         $dictionary = $this->file->addInfoDictionaryObject();
-        $dictionary->addTextEntry('Creator', 'famoser/pdf-generator/0.6');
+        $dictionary->addTextEntry('Producer', 'famoser/pdf-generator/'.self::GENERATOR_VERSION);
+        $dictionary->addTextEntry('Creator', 'famoser/pdf-generator/'.self::GENERATOR_VERSION);
         $dictionary->addDateEntry('CreationDate', new \DateTime());
+        $addTextIfNotNull = function (string $key, ?string $text) use ($dictionary) { if ($text) { $dictionary->addTextEntry($key, $text); }};
+        $addTextIfNotNull('Title', $structure->getMetadata()->getTitle());
+        $addTextIfNotNull('Author', $structure->getMetadata()->getAuthor());
+        $addTextIfNotNull('Keywords', $structure->getMetadata()->getKeywords());
 
         return $dictionary;
     }
@@ -81,6 +90,17 @@ public function visitPage(Page $structure): BaseObject
         return $dictionary;
     }
 
+    public function visitMetadata(Catalog\Metadata $structure): BaseObject
+    {
+        $stream = $this->file->addStreamObject($structure->getXml());
+
+        $dictionary = $stream->getMetaData();
+        $dictionary->setNameEntry('Type', 'Metadata');
+        $dictionary->setNameEntry('Subtype', 'XML');
+
+        return $stream;
+    }
+
     public function visitResources(Catalog\Resources $structure): BaseObject
     {
         $dictionary = $this->file->addDictionaryObject();
@@ -106,12 +126,12 @@ public function visitResources(Catalog\Resources $structure): BaseObject
     }
 
     /**
-     * @var BaseObject[]
+     * @var array<string, BaseObject>
      */
     private array $referenceLookup = [];
 
     /**
-     * @param BaseIdentifiableStructure[] $structures
+     * @param Catalog\Font[]|Catalog\Image[] $structures
      */
     private function createReferenceDictionary(array $structures): DictionaryToken
     {
@@ -145,7 +165,7 @@ public function visitContents(Catalog\Contents $structure): array
         return $baseObjects;
     }
 
-    public function visitType1Font(Catalog\Font\Type1 $structure): BaseObject
+    public function visitType1Font(Catalog\Font\Type1 $structure): DictionaryObject
     {
         $dictionary = $this->file->addDictionaryObject();
 

src/Backend/Structure/Document.php

@@ -16,6 +16,7 @@
 use Famoser\PdfGenerator\Backend\Catalog\Pages;
 use Famoser\PdfGenerator\Backend\Structure\Document\DocumentResources;
 use Famoser\PdfGenerator\Backend\Structure\Document\Page;
+use Famoser\PdfGenerator\Backend\Structure\Document\XmpMeta;
 use Famoser\PdfGenerator\Backend\Structure\Optimization\Configuration;
 
 class Document
@@ -27,7 +28,7 @@ class Document
 
     private readonly Configuration $configuration;
 
-    public function __construct()
+    public function __construct(private readonly XmpMeta $meta)
     {
         $this->configuration = new Configuration();
     }
@@ -40,17 +41,17 @@ public function addPage(Page $page): void
     public function render(): Catalog
     {
         $documentVisitor = new DocumentVisitor($this->configuration);
-        $documentResources = new DocumentResources($documentVisitor);
+        $meta = $this->meta->accept($documentVisitor);
 
-        /** @var CatalogPage[] $pageEntries */
+        $documentResources = new DocumentResources($documentVisitor);
         $pageEntries = [];
         foreach ($this->pages as $page) {
             $pageEntries[] = $page->render($documentResources);
         }
 
         $pages = new Pages($pageEntries);
 
-        return new Catalog($pages);
+        return new Catalog($pages, $meta);
     }
 
     public function save(): string