Implement po compiler

Author: cah4a

README.md

@@ -1,14 +1,7 @@
 # Dart gettext mo/po parser
 
 Parse and compile gettext po and mo files with dart.
-Port of npm package [gettext-parser](https://github.com/smhg/gettext-parser).
-
-## Readiness
-
-- [x] Mo parse
-- [ ] Mo compile
-- [x] Po parse
-- [ ] Po compile
+Ported [gettext-parser](https://github.com/smhg/gettext-parser) npm package to dartlang.
 
 ## Usage
 
@@ -23,27 +16,42 @@ Import library:
 import 'package:gettext_parser/gettext_parser.dart' as gettextParser;
 ```
 
-### Parse Mo Files:
+### Parse .po files:
+```dart
+Map translateTable = gettextParser.po.parse(
+    file.readAsStringSync(),
+);
+```
+
+### Parse .mo files:
 ```dart
 Map translateTable = gettextParser.mo.parse(
     file.readAsBytesSync(),
 );
 ```
 
-### Parse Po Files:
+### Compile .po files:
 ```dart
-Map translateTable = gettextParser.po.parse(
-    file.readAsStringSync(),
+String data = gettextParser.po.compile(
+    translateTable,
+);
+```
+
+### Compile .mo files:
+```dart
+UInt8List data = gettextParser.mo.compile(
+    translateTable,
 );
 ```
 
 ## Encoding
-`gettext_parser` use `Encoding` interface for encoding and decoding charsets from `dart:convert` package with utf8, base64, latin1 built-in encoders. If you need other encoding you could implement `Encoding` interface by your own.
+`gettext_parser` use `Encoding` interface for encoding and decoding charsets from `dart:convert` package with utf8, base64, latin1 built-in encoders.
+If you need other encoding you could implement `Encoding` interface by your own.
 
 Example:
 ```
 gettextParser.mo.parse(buffer, encoding: latin1);
-gettextParser.po.parseRaw(buffer, encoding: latin1);
+gettextParser.po.parse(buffer, encoding: latin1);
 ```
 
 ## Data structure of parsed mo/po files
@@ -103,7 +111,10 @@ Example
 }
 ```
 
-Notice that the structure has both a `headers` object and a `""` translation with the header string. When compiling the structure to a *mo* or a *po* file, the `headers` object is used to define the header. Header string in the `""` translation is just for reference (includes the original unmodified data) but will not be used when compiling. So if you need to add or alter header values, use only the `headers` object.
+Notice that the structure has both a `headers` object and a `""` translation with the header string.
+When compiling the structure to a *mo* or a *po* file, the `headers` object is used to define the header.
+Header string in the `""` translation is just for reference (includes the original unmodified data) but
+will not be used when compiling. So if you need to add or alter header values, use only the `headers` object.
 
 ## License
 

lib/gettext_parser.dart

@@ -1,10 +1,12 @@
-library mo_parser;
+library gettext_parser;
 
 import 'dart:convert';
+import 'dart:typed_data';
 
 import './src/mo/parser.dart';
 import './src/mo/compiler.dart';
 import './src/po/parser.dart';
+import './src/po/compiler.dart';
 
 const mo = const _Mo();
 const po = const _Po();
@@ -13,15 +15,24 @@ class _Mo {
   const _Mo();
 
   /// Parse mo file data with encoding
-  Map parse(List<int> buffer, {Encoding encoding: utf8}) {
-    final parser = new MoParser(buffer, encoding: encoding);
+  Map<String, dynamic> parse(ByteData data, {Encoding encoding: utf8}) {
+    final parser = MoParser(data, encoding: encoding);
     return parser.parse();
   }
 
-  /// Exposes general compiler function. Takes a translation
-  /// Map as a parameter and returns binary MO object
-  List<int> compile(Map table) {
-    final compiler = new MoCompiler(table);
+  /// Parse mo file data with encoding
+  Map<String, dynamic> parseBytes(List<int> data, {Encoding encoding: utf8}) {
+    final parser = MoParser(
+      ByteData.view(Uint8List.fromList(data).buffer),
+      encoding: encoding,
+    );
+
+    return parser.parse();
+  }
+
+  /// Converts [table] to a binary MO object
+  Uint8List compile(Map table) {
+    final compiler = MoCompiler(table);
     return compiler.compile();
   }
 }
@@ -30,14 +41,20 @@ class _Po {
   const _Po();
 
   /// Parse po data file with encoding
-  Map parseBytes(List<int> data, {Encoding encoding: utf8}) {
-    final parser = new PoParser(encoding.decode(data));
+  Map<String, dynamic> parseBytes(List<int> data, {Encoding encoding: utf8}) {
+    final parser = PoParser(encoding.decode(data));
     return parser.parse(charset: encoding.name);
   }
 
   /// Parse po file string
-  Map parse(String text) {
-    final parser = new PoParser(text);
+  Map<String, dynamic> parse(String text) {
+    final parser = PoParser(text);
     return parser.parse(charset: utf8.name);
   }
+
+  /// Converts [table] to a PO object
+  String compile(Map table) {
+    final compiler = PoCompiler(table);
+    return compiler.compile();
+  }
 }

lib/src/mo/compiler.dart

@@ -4,31 +4,33 @@ import '../models/table.dart';
 import '../models/translation.dart';
 import '../models/sizeOfData.dart';
 
-/// Creates a MO compiler object.
+/// Converts table to mo file.
 class MoCompiler {
   Table _table;
   Endian _endian = Endian.little;
 
-  // Magic bytes for the generated binary data
+  /// Magic bytes for the generated binary data
   static const _MAGIC = 0x950412de;
 
   MoCompiler(Map table) {
     _table = Table(table);
   }
 
-  List<int> compile () {
+  Uint8List compile() {
     final List<TranslationInterface> list = _generateList();
     final SizeOfData size = SizeOfData(list);
 
     // sort by msgid
-    list.sort((a, b) => utf8.decode(a.msgid.asUint8List()).compareTo(utf8.decode(b.msgid.asUint8List())));
+    list.sort((a, b) => utf8
+        .decode(a.msgid.asUint8List())
+        .compareTo(utf8.decode(b.msgid.asUint8List())));
 
     return this._build(list, size);
   }
 
-  // Generates an List of translation strings
-  // in the form of [TranslationInterface, ...]
-  List<TranslationInterface> _generateList () {
+  /// Generates an List of translation strings
+  /// in the form of [TranslationInterface, ...]
+  List<TranslationInterface> _generateList() {
     List<TranslationInterface> list = [];
 
     list.add(HeaderTranslation(this._table.headers));
@@ -46,7 +48,8 @@ class MoCompiler {
           return;
         }
 
-        String msgidPlural = this._table.translations[msgctxt][msgid]['msgid_plural'];
+        String msgidPlural =
+            this._table.translations[msgctxt][msgid]['msgid_plural'];
         String key = msgid;
         String value;
         List msgstr = this._table.translations[msgctxt][msgid]['msgstr'] ?? [];
@@ -68,7 +71,7 @@ class MoCompiler {
     return list;
   }
 
-  List<int> _build (List<TranslationInterface> list, SizeOfData size) {
+  Uint8List _build(List<TranslationInterface> list, SizeOfData size) {
     ByteData returnBuffer = ByteData.view(Uint8List(size.total).buffer);
     int currentPosition = 0;
 
@@ -85,23 +88,25 @@ class MoCompiler {
     returnBuffer.setUint32(12, 28, _endian);
 
     // translation string table offset
-    returnBuffer.setUint32(16, 28 + (4 + 4)*list.length, _endian);
+    returnBuffer.setUint32(16, 28 + (4 + 4) * list.length, _endian);
 
     // hash table size
     returnBuffer.setUint32(20, 0, _endian);
 
     // hash table offset
-    returnBuffer.setUint32(24, 28 + (4 + 4)*list.length*2, _endian);
+    returnBuffer.setUint32(24, 28 + (4 + 4) * list.length * 2, _endian);
 
     // build originals table
-    currentPosition = 28 + 2*(4 + 4)*list.length;
+    currentPosition = 28 + 2 * (4 + 4) * list.length;
     for (int i = 0, len = list.length; i < len; i++) {
       final Uint8List copy = list[i].msgid.asUint8List();
 
-      returnBuffer.buffer.asUint8List().setRange(currentPosition, currentPosition + copy.length, copy);
+      returnBuffer.buffer
+          .asUint8List()
+          .setRange(currentPosition, currentPosition + copy.length, copy);
 
-      returnBuffer.setUint32(28 + i*8, copy.length, _endian);
-      returnBuffer.setUint32(28 + i*8 + 4, currentPosition, _endian);
+      returnBuffer.setUint32(28 + i * 8, copy.length, _endian);
+      returnBuffer.setUint32(28 + i * 8 + 4, currentPosition, _endian);
       returnBuffer.setUint8(currentPosition + copy.length, 0x00);
 
       currentPosition += copy.length + 1;
@@ -111,15 +116,19 @@ class MoCompiler {
     for (int i = 0, len = list.length; i < len; i++) {
       final Uint8List copy = list[i].msgstr.asUint8List();
 
-      returnBuffer.buffer.asUint8List().setRange(currentPosition, currentPosition + copy.length, copy);
+      returnBuffer.buffer
+          .asUint8List()
+          .setRange(currentPosition, currentPosition + copy.length, copy);
 
-      returnBuffer.setUint32(28 + (4 + 4)*list.length + i*8, copy.length, _endian);
-      returnBuffer.setUint32(28 + (4 + 4)*list.length + i*8 + 4, currentPosition, _endian);
+      returnBuffer.setUint32(
+          28 + (4 + 4) * list.length + i * 8, copy.length, _endian);
+      returnBuffer.setUint32(
+          28 + (4 + 4) * list.length + i * 8 + 4, currentPosition, _endian);
       returnBuffer.setUint8(currentPosition + copy.length, 0x00);
 
       currentPosition += copy.length + 1;
     }
 
     return returnBuffer.buffer.asUint8List();
   }
-}
+}

lib/src/mo/parser.dart

@@ -23,14 +23,13 @@ class MoParser {
   int _offsetTranslations;
 
   // GetText revision nr, usually 0
-  int _revision;
+  int _revision; // ignore: unused_field
 
   // Total count of translated strings
   int _total;
 
-  MoParser(List<int> fileContent, {Encoding encoding}) {
+  MoParser(this._fileContents, {Encoding encoding}) {
     this.encoding = encoding ?? utf8;
-    this._fileContents = ByteData.view(Uint8List.fromList(fileContent).buffer);
 
     this._table = Table.fromCharset(charset: encoding.name);
   }
@@ -107,7 +106,7 @@ class MoParser {
   }
 
   /// Parses the MO object and returns translation table
-  Map parse() {
+  Map<String, dynamic> parse() {
     if (!this._checkMagick()) {
       return null;
     }

lib/src/models/table.dart

@@ -1,24 +1,29 @@
 class Table {
-  String charset;
-  String contentType;
-  Map headers;
-  Map translations;
+  Map<String, String> headers = {};
+  Map<String, Map<String, dynamic>> translations = {};
+  String charset = "";
+  String contentType = 'utf-8';
 
   Table(Map table) {
-    this.headers = table['headers'] ?? {};
-    this.translations = table['translations'] ?? {};
+    assert(table["headers"] is Map &&
+        table["headers"].values.every((value) => value is String));
+    assert(table['translations'] is Map &&
+        table['translations'].values.every((value) => value is Map));
+
+    headers = Map.castFrom(table["headers"]);
+    translations = Map.castFrom(table['translations']);
 
     _handleCharset(table);
   }
 
   Table.fromCharset({String charset = 'utf-8'}) {
     this.charset = charset;
-    this.translations = {};
   }
 
   // Handles header values, replaces or adds (if needed) a charset property
   void _handleCharset(Map table) {
-    final List<String> parts = (headers['content-type'] ?? 'text/plain').split(';');
+    final List<String> parts =
+        (headers['content-type'] ?? 'text/plain').split(';');
     final String contentType = parts.first;
     parts.removeAt(0);
     // Support only utf-8 encoding
@@ -82,4 +87,4 @@ class Table {
       'translations': this.translations,
     };
   }
-}
+}