diff --git a/epub3/lib/src/model.dart b/epub3/lib/src/model.dart
index db95405..485a4c0 100644
--- a/epub3/lib/src/model.dart
+++ b/epub3/lib/src/model.dart
@@ -179,25 +179,22 @@ class ItemRef {
   }
 }
 
-class Manifest {
+class Package {
   final Version version;
   final Metadata metadata;
-  final List<Item> items;
+  final Manifest manifest;
   final Spine spine;
-  // TODO: guide
-  Manifest({
-    required this.version,
-    required this.metadata,
-    required this.items,
-    required this.spine,
-  });
+  Package(this.version, this.metadata, this.manifest, this.spine);
+}
 
-  String get identifier => metadata.identifier.first.identifier;
+class Manifest {
+  final List<Item> items;
+  Manifest(this.items);
 
-  String tocFile() {
+  String tocFile(Version version) {
     Item? entry;
     if (version == Version.epub2) {
-      entry = items.where((element) => element.id == spine.toc).firstOrNull;
+      entry = items.where((element) => element.id == 'ncx').firstOrNull;
     } else if (version == Version.epub3) {
       // TODO: this is better?
       // id="nav" first
@@ -215,14 +212,19 @@ class Manifest {
     }
     return p.join('', entry?.href ?? '');
   }
+
+  Item? find(String id) {
+    return items.firstWhere((i) => i.id == id);
+  }
 }
 
 class Chapter {
   final String title;
   final String? href;
   final List<Chapter> children;
+
   /// raw content, always content of html file
-  final String? content; 
+  String? content;
 
   /// TODO: extract text from html document
   String get text => '';
@@ -232,7 +234,7 @@ class Chapter {
         (prev, c) => prev + c.chapterCount,
       );
 
-  const Chapter({
+  Chapter({
     required this.title,
     this.href,
     this.children = const [],
@@ -242,7 +244,10 @@ class Chapter {
   factory Chapter.textContent(String title, String text) {
     final href = title; // TODO:
     return Chapter(
-        title: title, href: href, content: Chapter.toHtml(title, text));
+        title: title,
+        href: href,
+        content: Chapter.toHtml(title, text),
+        children: []);
   }
 
 // transform text to HTML
@@ -326,20 +331,24 @@ abstract class ContentReader {
 }
 
 class Book {
+  final Version version;
   final Manifest manifest;
+  final Metadata metadata;
+  final Spine spine;
   final Navigation navigation;
+
+  /// Read content later
   final ContentReader? reader;
-  Book(this.manifest, this.navigation, this.reader);
+  Book(this.version, this.manifest, this.metadata, this.spine, this.navigation,
+      this.reader);
 
   factory Book.create(
       {required String title, required String author, ContentReader? reader}) {
     return Book(
-      Manifest(
-        version: Version.epub3,
-        metadata: Metadata.create(title, author),
-        items: [],
-        spine: Spine.empty(),
-      ),
+      Version.epub3,
+      Manifest([]),
+      Metadata.create(title, author),
+      Spine.empty(),
       Navigation(title: title, author: author, chapters: []),
       reader,
     );
@@ -350,21 +359,20 @@ class Book {
     manifest.items.addAll(chapter.items);
   }
 
-  Version get version => manifest.version;
+  String get identifier => metadata.identifier.first.identifier;
+
   String get title {
     if (navigation.title != null) {
       return navigation.title!;
     }
-    return manifest.metadata.title.isNotEmpty ? manifest.metadata.title[0] : '';
+    return metadata.title.isNotEmpty ? metadata.title[0] : '';
   }
 
   String get author {
     if (navigation.author != null) {
       return navigation.author!;
     }
-    return manifest.metadata.creator.isNotEmpty
-        ? manifest.metadata.creator[0].creator
-        : '';
+    return metadata.creator.isNotEmpty ? metadata.creator[0].creator : '';
   }
 
   String? get cover =>
@@ -380,7 +388,7 @@ class Book {
   Item? get nav {
     if (version == Version.epub2) {
       return manifest.items
-          .where((element) => element.id == manifest.spine.toc)
+          .where((element) => element.id == spine.toc)
           .firstOrNull;
     } else if (version == Version.epub3) {
       return manifest.items
@@ -390,14 +398,18 @@ class Book {
     return null;
   }
 
-  String? toHref(String id) {
-    return manifest.items.where((i) => i.id == id).firstOrNull?.href;
-  }
-
   String pathOf(String href) {
     final pos = href.indexOf('#');
-    final path = pos == -1 ? href : href.substring(0, pos);
-    return p.join(p.dirname(manifest.tocFile()), path);
+    String path = pos == -1 ? href : href.substring(0, pos);
+
+    // id, not file
+    if (p.extension(path).isEmpty) {
+      final item = manifest.find(path);
+      if (item != null) {
+        path = item.href!;
+      }
+    }
+    return p.join(p.dirname(manifest.tocFile(version)), path);
   }
 
   String? readString(String href) {
diff --git a/epub3/lib/src/reader.dart b/epub3/lib/src/reader.dart
index d63835f..31c56da 100644
--- a/epub3/lib/src/reader.dart
+++ b/epub3/lib/src/reader.dart
@@ -7,7 +7,7 @@ import 'package:xml/xpath.dart' as xml;
 
 import 'model.dart';
 
-/// [Reader] read scheme and content from epub file.
+/// [Reader] read `package document` and content from zip file.
 class Reader extends ContentReader {
   factory Reader.open(Archive archive) {
     final rootFile = extractRootFileName(archive);
@@ -23,21 +23,31 @@ class Reader extends ContentReader {
 
   static const opfNS = 'http://www.idpf.org/2007/opf';
 
-  Book? read() {
-    final scheme = readSchema(rootFile);
-    if (scheme == null) {
+  Book? read({bool extractContent = false}) {
+    final package = parsePackage(rootFile);
+    if (package == null) {
       return null;
     }
 
-    final navfile = pathOf(scheme.tocFile());
-    final nav = scheme.version == Version.epub2
+    final navfile = package.manifest.tocFile(package.version);
+    final nav = package.version == Version.epub2
         ? readNavigation2(navfile)
         : readNavigation3(navfile);
-    return Book(scheme, nav ?? Navigation(chapters: []), this);
+    final book = Book(package.version, package.manifest, package.metadata,
+        package.spine, nav ?? Navigation(chapters: []), this);
+
+    if (extractContent) {
+      book.chapters.forEach((ch) => _loadContent(book, ch));
+    }
+    return book;
   }
 
-  /// Relative path by rootfile
-  String pathOf(String fp) => p.join(p.dirname(rootFile), fp);
+  void _loadContent(Book book, Chapter ch) {
+    ch.content = book.readString(ch.href!);
+    for (Chapter sub in ch.children) {
+      _loadContent(book, sub);
+    }
+  }
 
   static const containerFN = 'META-INF/container.xml';
 
@@ -59,8 +69,8 @@ class Reader extends ContentReader {
     return null;
   }
 
-  /// Read [Manifest] from OEBPS/content.opf
-  Manifest? readSchema(String path) {
+  /// Parse Package document normal as OEBPS/content.opf
+  Package? parsePackage(String path) {
     // root element, <package>
     var doc = _readAsXml(path);
     if (doc == null) return null;
@@ -76,13 +86,13 @@ class Reader extends ContentReader {
       throw Exception('Unsupported EPUB version: $vs.');
     }
 
-    return Manifest(
-      version: version,
-      metadata: _extractMetadata(
+    return Package(
+      version,
+      _extractMetadata(
           doc.findElements('metadata', namespace: opfNS).first, version),
-      items: _extractManifest(
-          doc.findElements('manifest', namespace: opfNS).first),
-      spine: _extractSpine(doc.findElements('spine', namespace: opfNS).first),
+      Manifest(_extractManifest(
+          doc.findElements('manifest', namespace: opfNS).first)),
+      _extractSpine(doc.findElements('spine', namespace: opfNS).first),
     );
   }
 
@@ -212,7 +222,7 @@ class Reader extends ContentReader {
       .toList();
 
   Navigation? readNavigation2(String path) {
-    final doc = _readAsXml(path);
+    final doc = _readAsXml(pathOf(path));
     if (doc == null) return null;
 
     return _readNav2(doc);
@@ -242,7 +252,7 @@ class Reader extends ContentReader {
   /// path maybe "EPUB/xhtml/epub30-nav.xhtml"
   /// nav / ol / li / span|a
   Navigation? readNavigation3(String path) {
-    final doc = _readAsXml(path);
+    final doc = _readAsXml(pathOf(path));
     if (doc == null) return null;
 
     if (doc.localName == 'ncx') {
@@ -269,23 +279,25 @@ class Reader extends ContentReader {
     final a = li.findElements('a').firstOrNull;
 
     final id = li.getAttribute('id');
-    final href = id == null ? id : a?.getAttribute('href');
+    final href = id != null ? id : a?.getAttribute('href');
 
     return Chapter(
       title: clean(span != null ? span.innerText : a?.innerText ?? ''),
       href: href,
       children: _readOl(li),
-      // TODO: content #2
     );
   }
 
+  /// Relative path by rootfile
+  String pathOf(String fp) => p.join(p.dirname(rootFile), fp);
+
   /// Read an [ArchiveFile]
   ArchiveFile? readFile(String path) {
     assert(path.indexOf('#') == -1);
 
     // pathOf for relative path
     // normalize for avoid ./
-    path = p.normalize(pathOf(path));
+    path = pathOf(p.normalize(path));
 
     return archive.files
         .firstWhereOrNull((ArchiveFile file) => file.name == path);
diff --git a/epub3/lib/src/writer.dart b/epub3/lib/src/writer.dart
index c075dcf..ce7c224 100644
--- a/epub3/lib/src/writer.dart
+++ b/epub3/lib/src/writer.dart
@@ -73,7 +73,7 @@ class Writer {
     final out = xml.XmlBuilder();
     out.processing('xml', 'version="1.0"');
 
-    final uid = manifest.metadata.identifier.first.id;
+    final uid = book.metadata.identifier.first.id;
     out.element(
       'package',
       namespaces: {Reader.opfNS: null},
@@ -86,7 +86,7 @@ class Writer {
             'identifier',
             namespace: dcuri,
             attributes: {'id': uid}, // same id as [1]
-            nest: manifest.metadata.identifier.first.identifier,
+            nest: book.metadata.identifier.first.identifier,
           );
           out.element('title', namespace: dcuri, nest: book.title);
           out.element('language', namespace: dcuri, nest: 'en');
@@ -116,7 +116,7 @@ class Writer {
 
         out.element('spine', // attributes: {'toc': manifest.spine.toc},
             nest: () {
-          for (var i in manifest.spine.refs) {
+          for (var i in book.spine.refs) {
             out.element('itemref', attributes: i.attributes);
           }
           out.element('itemref', attributes: {'idref': 'nav'});
diff --git a/epub3/pubspec.yaml b/epub3/pubspec.yaml
index 018b7dc..592ab90 100644
--- a/epub3/pubspec.yaml
+++ b/epub3/pubspec.yaml
@@ -1,7 +1,7 @@
 name: epub3
 description: Read and Write Epub3 files.
 homepage: https://github.com/pedia/epub3
-version: 0.2.2
+version: 0.3.0
 
 environment:
   sdk: '>=2.14.0 <4.0.0'
diff --git a/epub3/test/reader_test.dart b/epub3/test/reader_test.dart
index 552a3ce..2f381c7 100644
--- a/epub3/test/reader_test.dart
+++ b/epub3/test/reader_test.dart
@@ -30,17 +30,7 @@ void main() {
     'test/res/std/linear-algebra.epub',
   ];
 
-  const csharput = [
-    'test/res/53.epub',
-    'test/res/55.epub',
-    'test/res/57.epub',
-    'test/res/invalid-manifest-epub2.epub',
-    'test/res/invalid-manifest-epub3.epub',
-    'test/res/missing-navigation-point.epub',
-    'test/res/missing-toc.epub',
-    'test/res/remote-content.epub',
-    'test/res/xml11.epub',
-  ];
+  
 
   test('epub2', () {
     final r = Reader.open(
@@ -48,26 +38,26 @@ void main() {
     final book = r.read();
     expect(book!.version, Version.epub2);
     expect(
-        book.manifest.metadata.title, equals(['Test title 1', 'Test title 2']));
+        book.metadata.title, equals(['Test title 1', 'Test title 2']));
     expect(
       MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author') ==
           MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author'),
       isTrue,
     );
     expect(
-        book.manifest.metadata.creator,
+        book.metadata.creator,
         equals([
           MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author'),
           MetaCreator('Jane Doe', fileAs: 'Doe, Jane', role: 'author'),
         ]));
     expect(
-        book.manifest.metadata.contributor,
+        book.metadata.contributor,
         equals([
           MetaCreator('John Editor', fileAs: 'Editor, John', role: 'editor'),
           MetaCreator('Jane Editor', fileAs: 'Editor, Jane', role: 'editor'),
         ]));
     expect(
-        book.manifest.metadata.identifier,
+        book.metadata.identifier,
         equals([
           MetaIdentifier(
             identifier: 'https://example.com/books/123',
@@ -80,15 +70,15 @@ void main() {
             scheme: 'ISBN',
           ),
         ]));
-    expect(book.manifest.metadata.subject,
+    expect(book.metadata.subject,
         equals(['Test subject 1', 'Test subject 2']));
-    expect(book.manifest.metadata.publisher,
+    expect(book.metadata.publisher,
         equals(['Test publisher 1', 'Test publisher 2']));
-    expect(book.manifest.metadata.description, equals(['Test description']));
-    expect(book.manifest.metadata.type, equals(['dictionary', 'preview']));
-    expect(book.manifest.metadata.format, equals(['format-1', 'format-2']));
+    expect(book.metadata.description, equals(['Test description']));
+    expect(book.metadata.type, equals(['dictionary', 'preview']));
+    expect(book.metadata.format, equals(['format-1', 'format-2']));
     expect(
-        book.manifest.metadata.source,
+        book.metadata.source,
         equals([
           'https://example.com/books/123/content-1.html',
           'https://example.com/books/123/content-2.html',
@@ -128,25 +118,25 @@ void main() {
     final book = readFile('test/res/epub3.epub');
     expect(book!.version, Version.epub3);
     expect(
-        book.manifest.metadata.title, equals(['Test title 1', 'Test title 2']));
+        book.metadata.title, equals(['Test title 1', 'Test title 2']));
     expect(
       MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author'),
       MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author'),
     );
     expect(
-        book.manifest.metadata.creator,
+        book.metadata.creator,
         equals([
           MetaCreator('John Doe', fileAs: 'Doe, John', role: 'author'),
           MetaCreator('Jane Doe', fileAs: 'Doe, Jane', role: 'author'),
         ]));
     expect(
-        book.manifest.metadata.contributor,
+        book.metadata.contributor,
         equals([
           MetaCreator('John Editor', fileAs: 'Editor, John', role: 'editor'),
           MetaCreator('Jane Editor', fileAs: 'Editor, Jane', role: 'editor'),
         ]));
     expect(
-        book.manifest.metadata.identifier,
+        book.metadata.identifier,
         equals([
           MetaIdentifier(
             identifier: 'https://example.com/books/123',
@@ -159,15 +149,15 @@ void main() {
             scheme: 'ISBN',
           ),
         ]));
-    expect(book.manifest.metadata.subject,
+    expect(book.metadata.subject,
         equals(['Test subject 1', 'Test subject 2']));
-    expect(book.manifest.metadata.publisher,
+    expect(book.metadata.publisher,
         equals(['Test publisher 1', 'Test publisher 2']));
-    expect(book.manifest.metadata.description, equals(['Test description']));
-    expect(book.manifest.metadata.type, equals(['dictionary', 'preview']));
-    expect(book.manifest.metadata.format, equals(['format-1', 'format-2']));
+    expect(book.metadata.description, equals(['Test description']));
+    expect(book.metadata.type, equals(['dictionary', 'preview']));
+    expect(book.metadata.format, equals(['format-1', 'format-2']));
     expect(
-        book.manifest.metadata.source,
+        book.metadata.source,
         equals([
           'https://example.com/books/123/content-1.html',
           'https://example.com/books/123/content-2.html',
@@ -185,12 +175,12 @@ void main() {
 
     expect(book.navigation.chapterCount, 5);
     expect(
-        book.navigation.chapters[0],
+        book.chapters[0],
         equals(Chapter(title: 'Test span header 1', children: [
           Chapter(title: 'Chapter 1', href: 'chapter1.html', children: []),
         ])));
     expect(
-        book.navigation.chapters[1],
+        book.chapters[1],
         equals(Chapter(title: 'Test span header 2', children: [
           Chapter(title: 'Chapter 2', href: 'chapter2.html', children: []),
           Chapter(title: 'Chapter 3', href: 'chapter3.html', children: []),
@@ -227,7 +217,7 @@ void main() {
       readit(Chapter c) {
         if (c.href != null) {
           final af = book.readBytes(c.href!);
-          expect(af, isNotNull);
+          expect(af, isNotNull, reason: '$f ${c.href} "${c.title}"');
         }
         for (var cc in c.children) {
           readit(cc);
@@ -240,6 +230,18 @@ void main() {
     }
   });
 
+  const csharput = [
+    'test/res/53.epub',
+    'test/res/55.epub',
+    'test/res/57.epub',
+    'test/res/invalid-manifest-epub2.epub',
+    'test/res/invalid-manifest-epub3.epub',
+    'test/res/missing-navigation-point.epub',
+    'test/res/missing-toc.epub',
+    'test/res/remote-content.epub',
+    'test/res/xml11.epub',
+  ];
+
   test('malformed', () {
     csharput.forEach((f) {
       print('epub: $f');
diff --git a/epub3/test/writer_test.dart b/epub3/test/writer_test.dart
index a103c55..acec685 100644
--- a/epub3/test/writer_test.dart
+++ b/epub3/test/writer_test.dart
@@ -1,3 +1,5 @@
+import 'dart:io';
+import 'package:archive/archive_io.dart';
 import 'package:epub3/epub3_io.dart';
 import 'package:test/test.dart';
 import 'package:archive/archive.dart';
@@ -51,4 +53,26 @@ void main() {
       }
     }
   });
+
+  test('content with children', () {
+    final book1 = Book.create(title: 'title', author: 'author');
+    book1.add(Chapter(title: 'c1', content: 'c1-body', children: [
+      Chapter(title: 'c11', content: 'c11-body'),
+      Chapter(title: 'c12', content: 'c12-body'),
+    ]));
+    book1.add(Chapter(title: 'c2', content: 'c2-body', children: [
+      Chapter(title: 'c21', content: 'c21-body', children: [
+        Chapter(title: 'c211', content: 'c211-body'),
+      ]),
+      Chapter(title: 'c22', content: 'c22-body'),
+    ]));
+
+    final a = Archive();
+    Writer(book1).write(a);
+    File('foo.epub')..createSync()..writeAsBytesSync(ZipEncoder().encode(a)!);
+
+    final book2 = Reader.open(a).read(extractContent: true);
+    expect(book2?.chapters.length, 2);
+    expect(book2?.chapters.first.content, 'c1-body');
+  });
 }
diff --git a/epubview/lib/epubview.dart b/epubview/lib/epubview.dart
index fa294bd..34b341b 100644
--- a/epubview/lib/epubview.dart
+++ b/epubview/lib/epubview.dart
@@ -12,6 +12,7 @@ class Calculator {
   int addOne(int value) => value + 1;
 }
 
+/// none-tree-liked Chapter
 class Chapter {
   Chapter({required this.title, this.href, this.parent});
   final String title;
@@ -40,25 +41,24 @@ class Chapter {
   }
 }
 
-class ChapterView extends StatelessWidget {
+class ReaderState extends ChangeNotifier {
+  final epub.Book book;
   final List<Chapter> chapters;
-  final String? href;
-  final void Function(Chapter)? onChapterSelect;
-  const ChapterView({
-    required this.chapters,
-    this.href,
-    this.onChapterSelect,
-    super.key,
-  });
-
-  factory ChapterView.from(
-    epub.Book book, {
-    void Function(Chapter)? onChapterSelect,
-  }) =>
-      ChapterView(
-        chapters: Chapter.build(book),
-        onChapterSelect: onChapterSelect,
-      );
+  Chapter? chapter;
+
+  ReaderState(this.book) : chapters = Chapter.build(book);
+
+  void setCurrent(Chapter ch) {
+    chapter = ch;
+    notifyListeners();
+  }
+}
+
+class ChapterView extends StatelessWidget {
+  final ReaderState rs;
+  const ChapterView(this.rs, {super.key});
+
+  factory ChapterView.from(epub.Book book) => ChapterView(ReaderState(book));
 
   @override
   Widget build(BuildContext context) {
@@ -67,17 +67,18 @@ class ChapterView extends StatelessWidget {
         // print(
         //     'tile font: ${Theme.of(context).textTheme.bodyMedium?.fontFamily} '
         //     '${Theme.of(context).textTheme.bodyMedium?.fontFamilyFallback}');
-        final ch = chapters[index];
+        final ch = rs.chapters[index];
         return ListTile(
           leading: ch.parent == null ? null : const Text(''),
           title: Text(ch.title),
+          selected: rs.chapter == ch,
           onTap: () {
-            onChapterSelect?.call(ch);
+            rs.setCurrent(ch);
             print('click ${ch.href}');
           },
         );
       },
-      itemCount: chapters.length,
+      itemCount: rs.chapters.length,
     );
   }
 }