/* GNU gettext for C#
* Copyright (C) 2003, 2005, 2007, 2015 Free Software Foundation, Inc.
* Written by Bruno Haible <bruno@clisp.org>, 2003.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Using the GNU gettext approach, compiled message catalogs are assemblies
* containing just one class, a subclass of GettextResourceSet. They are thus
* interoperable with standard ResourceManager based code.
*
* The main differences between the common .NET resources approach and the
* GNU gettext approach are:
* - In the .NET resource approach, the keys are abstract textual shortcuts.
* In the GNU gettext approach, the keys are the English/ASCII version
* of the messages.
* - In the .NET resource approach, the translation files are called
* "Resource.locale.resx" and are UTF-8 encoded XML files. In the GNU gettext
* approach, the translation files are called "Resource.locale.po" and are
* in the encoding the translator has chosen. There are at least three GUI
* translating tools (Emacs PO mode, KDE KBabel, GNOME gtranslator).
* - In the .NET resource approach, the function ResourceManager.GetString
* returns an empty string or throws an InvalidOperationException when no
* translation is found. In the GNU gettext approach, the GetString function
* returns the (English) message key in that case.
* - In the .NET resource approach, there is no support for plural handling.
* In the GNU gettext approach, we have the GetPluralString function.
* - In the .NET resource approach, there is no support for context specific
* translations.
* In the GNU gettext approach, we have the GetParticularString function.
*
* To compile GNU gettext message catalogs into C# assemblies, the msgfmt
* program can be used.
*/
using System; /* String, InvalidOperationException, Console */
using System.Globalization; /* CultureInfo */
using System.Resources; /* ResourceManager, ResourceSet, IResourceReader */
using System.Reflection; /* Assembly, ConstructorInfo */
using System.Collections; /* Hashtable, ICollection, IEnumerator, IDictionaryEnumerator */
using System.IO; /* Path, FileNotFoundException, Stream */
using System.Text; /* StringBuilder */
namespace GNU.Gettext {
/// <summary>
/// Each instance of this class can be used to lookup translations for a
/// given resource name. For each <c>CultureInfo</c>, it performs the lookup
/// in several assemblies, from most specific over territory-neutral to
/// language-neutral.
/// </summary>
public class GettextResourceManager : ResourceManager {
// ======================== Public Constructors ========================
/// <summary>
/// Constructor.
/// </summary>
/// <param name="baseName">the resource name, also the assembly base
/// name</param>
public GettextResourceManager (String baseName)
: base (baseName, Assembly.GetCallingAssembly(), typeof (GettextResourceSet)) {
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="baseName">the resource name, also the assembly base
/// name</param>
public GettextResourceManager (String baseName, Assembly assembly)
: base (baseName, assembly, typeof (GettextResourceSet)) {
}
// ======================== Implementation ========================
/// <summary>
/// Loads and returns a satellite assembly.
/// </summary>
// This is like Assembly.GetSatelliteAssembly, but uses resourceName
// instead of assembly.GetName().Name, and works around a bug in
// mono-0.28.
private static Assembly GetSatelliteAssembly (Assembly assembly, String resourceName, CultureInfo culture) {
String satelliteExpectedLocation =
Path.GetDirectoryName(assembly.Location)
+ Path.DirectorySeparatorChar + culture.Name
+ Path.DirectorySeparatorChar + resourceName + ".resources.dll";
return Assembly.LoadFrom(satelliteExpectedLocation);
}
/// <summary>
/// Loads and returns the satellite assembly for a given culture.
/// </summary>
private Assembly MySatelliteAssembly (CultureInfo culture) {
return GetSatelliteAssembly(MainAssembly, BaseName, culture);
}
/// <summary>
/// Converts a resource name to a class name.
/// </summary>
/// <returns>a nonempty string consisting of alphanumerics and underscores
/// and starting with a letter or underscore</returns>
private static String ConstructClassName (String resourceName) {
// We could just return an arbitrary fixed class name, like "Messages",
// assuming that every assembly will only ever contain one
// GettextResourceSet subclass, but this assumption would break the day
// we want to support multi-domain PO files in the same format...
bool valid = (resourceName.Length > 0);
for (int i = 0; valid && i < resourceName.Length; i++) {
char c = resourceName[i];
if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c == '_')
|| (i > 0 && c >= '0' && c <= '9')))
valid = false;
}
if (valid)
return resourceName;
else {
// Use hexadecimal escapes, using the underscore as escape character.
String hexdigit = "0123456789abcdef";
StringBuilder b = new StringBuilder();
b.Append("__UESCAPED__");
for (int i = 0; i < resourceName.Length; i++) {
char c = resourceName[i];
if (c >= 0xd800 && c < 0xdc00
&& i+1 < resourceName.Length
&& resourceName[i+1] >= 0xdc00 && resourceName[i+1] < 0xe000) {
// Combine two UTF-16 words to a character.
char c2 = resourceName[i+1];
int uc = 0x10000 + ((c - 0xd800) << 10) + (c2 - 0xdc00);
b.Append('_');
b.Append('U');
b.Append(hexdigit[(uc >> 28) & 0x0f]);
b.Append(hexdigit[(uc >> 24) & 0x0f]);
b.Append(hexdigit[(uc >> 20) & 0x0f]);
b.Append(hexdigit[(uc >> 16) & 0x0f]);
b.Append(hexdigit[(uc >> 12) & 0x0f]);
b.Append(hexdigit[(uc >> 8) & 0x0f]);
b.Append(hexdigit[(uc >> 4) & 0x0f]);
b.Append(hexdigit[uc & 0x0f]);
i++;
} else if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')
|| (c >= '0' && c <= '9'))) {
int uc = c;
b.Append('_');
b.Append('u');
b.Append(hexdigit[(uc >> 12) & 0x0f]);
b.Append(hexdigit[(uc >> 8) & 0x0f]);
b.Append(hexdigit[(uc >> 4) & 0x0f]);
b.Append(hexdigit[uc & 0x0f]);
} else
b.Append(c);
}
return b.ToString();
}
}
/// <summary>
/// Instantiates a resource set for a given culture.
/// </summary>
/// <exception cref="ArgumentException">
/// The expected type name is not valid.
/// </exception>
/// <exception cref="ReflectionTypeLoadException">
/// satelliteAssembly does not contain the expected type.
/// </exception>
/// <exception cref="NullReferenceException">
/// The type has no no-arguments constructor.
/// </exception>
private static GettextResourceSet InstantiateResourceSet (Assembly satelliteAssembly, String resourceName, CultureInfo culture) {
// We expect a class with a culture dependent class name.
Type clazz = satelliteAssembly.GetType(ConstructClassName(resourceName)+"_"+culture.Name.Replace('-','_'));
// We expect it has a no-argument constructor, and invoke it.
ConstructorInfo constructor = clazz.GetConstructor(Type.EmptyTypes);
return (GettextResourceSet) constructor.Invoke(null);
}
private static GettextResourceSet[] EmptyResourceSetArray = new GettextResourceSet[0];
// Cache for already loaded GettextResourceSet cascades.
private Hashtable /* CultureInfo -> GettextResourceSet[] */ Loaded = new Hashtable();
/// <summary>
/// Returns the array of <c>GettextResourceSet</c>s for a given culture,
/// loading them if necessary, and maintaining the cache.
/// </summary>
private GettextResourceSet[] GetResourceSetsFor (CultureInfo culture) {
//Console.WriteLine(">> GetResourceSetsFor "+culture);
// Look up in the cache.
GettextResourceSet[] result = (GettextResourceSet[]) Loaded[culture];
if (result == null) {
lock(this) {
// Look up again - maybe another thread has filled in the entry
// while we slept waiting for the lock.
result = (GettextResourceSet[]) Loaded[culture];
if (result == null) {
// Determine the GettextResourceSets for the given culture.
if (culture.Parent == null || culture.Equals(CultureInfo.InvariantCulture))
// Invariant culture.
result = EmptyResourceSetArray;
else {
// Use a satellite assembly as primary GettextResourceSet, and
// the result for the parent culture as fallback.
GettextResourceSet[] parentResult = GetResourceSetsFor(culture.Parent);
Assembly satelliteAssembly;
try {
satelliteAssembly = MySatelliteAssembly(culture);
} catch (FileNotFoundException e) {
satelliteAssembly = null;
}
if (satelliteAssembly != null) {
GettextResourceSet satelliteResourceSet;
try {
satelliteResourceSet = InstantiateResourceSet(satelliteAssembly, BaseName, culture);
} catch (Exception e) {
Console.Error.WriteLine(e);
Console.Error.WriteLine(e.StackTrace);
satelliteResourceSet = null;
}
if (satelliteResourceSet != null) {
result = new GettextResourceSet[1+parentResult.Length];
result[0] = satelliteResourceSet;
Array.Copy(parentResult, 0, result, 1, parentResult.Length);
} else
result = parentResult;
} else
result = parentResult;
}
// Put the result into the cache.
Loaded.Add(culture, result);
}
}
}
//Console.WriteLine("<< GetResourceSetsFor "+culture);
return result;
}
/*
/// <summary>
/// Releases all loaded <c>GettextResourceSet</c>s and their assemblies.
/// </summary>
// TODO: No way to release an Assembly?
public override void ReleaseAllResources () {
...
}
*/
/// <summary>
/// Returns the translation of <paramref name="msgid"/> in a given culture.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or
/// <paramref name="msgid"/> if none is found</returns>
public override String GetString (String msgid, CultureInfo culture) {
foreach (GettextResourceSet rs in GetResourceSetsFor(culture)) {
String translation = rs.GetString(msgid);
if (translation != null)
return translation;
}
// Fallback.
return msgid;
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> and
/// <paramref name="msgidPlural"/> in a given culture, choosing the right
/// plural form depending on the number <paramref name="n"/>.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <param name="msgidPlural">the English plural of <paramref name="msgid"/>,
/// an ASCII string</param>
/// <param name="n">the number, should be >= 0</param>
/// <returns>the translation, or <paramref name="msgid"/> or
/// <paramref name="msgidPlural"/> if none is found</returns>
public virtual String GetPluralString (String msgid, String msgidPlural, long n, CultureInfo culture) {
foreach (GettextResourceSet rs in GetResourceSetsFor(culture)) {
String translation = rs.GetPluralString(msgid, msgidPlural, n);
if (translation != null)
return translation;
}
// Fallback: Germanic plural form.
return (n == 1 ? msgid : msgidPlural);
}
// ======================== Public Methods ========================
/// <summary>
/// Returns the translation of <paramref name="msgid"/> in the context
/// of <paramref name="msgctxt"/> a given culture.
/// </summary>
/// <param name="msgctxt">the context for the key string, an ASCII
/// string</param>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or
/// <paramref name="msgid"/> if none is found</returns>
public String GetParticularString (String msgctxt, String msgid, CultureInfo culture) {
String combined = msgctxt + "\u0004" + msgid;
foreach (GettextResourceSet rs in GetResourceSetsFor(culture)) {
String translation = rs.GetString(combined);
if (translation != null)
return translation;
}
// Fallback.
return msgid;
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> and
/// <paramref name="msgidPlural"/> in the context of
/// <paramref name="msgctxt"/> in a given culture, choosing the right
/// plural form depending on the number <paramref name="n"/>.
/// </summary>
/// <param name="msgctxt">the context for the key string, an ASCII
/// string</param>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <param name="msgidPlural">the English plural of <paramref name="msgid"/>,
/// an ASCII string</param>
/// <param name="n">the number, should be >= 0</param>
/// <returns>the translation, or <paramref name="msgid"/> or
/// <paramref name="msgidPlural"/> if none is found</returns>
public virtual String GetParticularPluralString (String msgctxt, String msgid, String msgidPlural, long n, CultureInfo culture) {
String combined = msgctxt + "\u0004" + msgid;
foreach (GettextResourceSet rs in GetResourceSetsFor(culture)) {
String translation = rs.GetPluralString(combined, msgidPlural, n);
if (translation != null)
return translation;
}
// Fallback: Germanic plural form.
return (n == 1 ? msgid : msgidPlural);
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> in the current
/// culture.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or
/// <paramref name="msgid"/> if none is found</returns>
public override String GetString (String msgid) {
return GetString(msgid, CultureInfo.CurrentUICulture);
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> and
/// <paramref name="msgidPlural"/> in the current culture, choosing the
/// right plural form depending on the number <paramref name="n"/>.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <param name="msgidPlural">the English plural of <paramref name="msgid"/>,
/// an ASCII string</param>
/// <param name="n">the number, should be >= 0</param>
/// <returns>the translation, or <paramref name="msgid"/> or
/// <paramref name="msgidPlural"/> if none is found</returns>
public virtual String GetPluralString (String msgid, String msgidPlural, long n) {
return GetPluralString(msgid, msgidPlural, n, CultureInfo.CurrentUICulture);
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> in the context
/// of <paramref name="msgctxt"/> in the current culture.
/// </summary>
/// <param name="msgctxt">the context for the key string, an ASCII
/// string</param>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or
/// <paramref name="msgid"/> if none is found</returns>
public String GetParticularString (String msgctxt, String msgid) {
return GetParticularString(msgctxt, msgid, CultureInfo.CurrentUICulture);
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> and
/// <paramref name="msgidPlural"/> in the context of
/// <paramref name="msgctxt"/> in the current culture, choosing the
/// right plural form depending on the number <paramref name="n"/>.
/// </summary>
/// <param name="msgctxt">the context for the key string, an ASCII
/// string</param>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <param name="msgidPlural">the English plural of <paramref name="msgid"/>,
/// an ASCII string</param>
/// <param name="n">the number, should be >= 0</param>
/// <returns>the translation, or <paramref name="msgid"/> or
/// <paramref name="msgidPlural"/> if none is found</returns>
public virtual String GetParticularPluralString (String msgctxt, String msgid, String msgidPlural, long n) {
return GetParticularPluralString(msgctxt, msgid, msgidPlural, n, CultureInfo.CurrentUICulture);
}
}
/// <summary>
/// <para>
/// Each instance of this class encapsulates a single PO file.
/// </para>
/// <para>
/// This API of this class is not meant to be used directly; use
/// <c>GettextResourceManager</c> instead.
/// </para>
/// </summary>
// We need this subclass of ResourceSet, because the plural formula must come
// from the same ResourceSet as the object containing the plural forms.
public class GettextResourceSet : ResourceSet {
/// <summary>
/// Creates a new message catalog. When using this constructor, you
/// must override the <c>ReadResources</c> method, in order to initialize
/// the <c>Table</c> property. The message catalog will support plural
/// forms only if the <c>ReadResources</c> method installs values of type
/// <c>String[]</c> and if the <c>PluralEval</c> method is overridden.
/// </summary>
protected GettextResourceSet ()
: base (DummyResourceReader) {
}
/// <summary>
/// Creates a new message catalog, by reading the string/value pairs from
/// the given <paramref name="reader"/>. The message catalog will support
/// plural forms only if the reader can produce values of type
/// <c>String[]</c> and if the <c>PluralEval</c> method is overridden.
/// </summary>
public GettextResourceSet (IResourceReader reader)
: base (reader) {
}
/// <summary>
/// Creates a new message catalog, by reading the string/value pairs from
/// the given <paramref name="stream"/>, which should have the format of
/// a <c>.resources</c> file. The message catalog will not support plural
/// forms.
/// </summary>
public GettextResourceSet (Stream stream)
: base (stream) {
}
/// <summary>
/// Creates a new message catalog, by reading the string/value pairs from
/// the file with the given <paramref name="fileName"/>. The file should
/// be in the format of a <c>.resources</c> file. The message catalog will
/// not support plural forms.
/// </summary>
public GettextResourceSet (String fileName)
: base (fileName) {
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/>.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or <c>null</c> if
/// none is found</returns>
// The default implementation essentially does (String)Table[msgid].
// Here we also catch the plural form case.
public override String GetString (String msgid) {
Object value = GetObject(msgid);
if (value == null || value is String)
return (String)value;
else if (value is String[])
// A plural form, but no number is given.
// Like the C implementation, return the first plural form.
return ((String[]) value)[0];
else
throw new InvalidOperationException("resource for \""+msgid+"\" in "+GetType().FullName+" is not a string");
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/>, with possibly
/// case-insensitive lookup.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <returns>the translation of <paramref name="msgid"/>, or <c>null</c> if
/// none is found</returns>
// The default implementation essentially does (String)Table[msgid].
// Here we also catch the plural form case.
public override String GetString (String msgid, bool ignoreCase) {
Object value = GetObject(msgid, ignoreCase);
if (value == null || value is String)
return (String)value;
else if (value is String[])
// A plural form, but no number is given.
// Like the C implementation, return the first plural form.
return ((String[]) value)[0];
else
throw new InvalidOperationException("resource for \""+msgid+"\" in "+GetType().FullName+" is not a string");
}
/// <summary>
/// Returns the translation of <paramref name="msgid"/> and
/// <paramref name="msgidPlural"/>, choosing the right plural form
/// depending on the number <paramref name="n"/>.
/// </summary>
/// <param name="msgid">the key string to be translated, an ASCII
/// string</param>
/// <param name="msgidPlural">the English plural of <paramref name="msgid"/>,
/// an ASCII string</param>
/// <param name="n">the number, should be >= 0</param>
/// <returns>the translation, or <c>null</c> if none is found</returns>
public virtual String GetPluralString (String msgid, String msgidPlural, long n) {
Object value = GetObject(msgid);
if (value == null || value is String)
return (String)value;
else if (value is String[]) {
String[] choices = (String[]) value;
long index = PluralEval(n);
return choices[index >= 0 && index < choices.Length ? index : 0];
} else
throw new InvalidOperationException("resource for \""+msgid+"\" in "+GetType().FullName+" is not a string");
}
/// <summary>
/// Returns the index of the plural form to be chosen for a given number.
/// The default implementation is the Germanic plural formula:
/// zero for <paramref name="n"/> == 1, one for <paramref name="n"/> != 1.
/// </summary>
protected virtual long PluralEval (long n) {
return (n == 1 ? 0 : 1);
}
/// <summary>
/// Returns the keys of this resource set, i.e. the strings for which
/// <c>GetObject()</c> can return a non-null value.
/// </summary>
public virtual ICollection Keys {
get {
return Table.Keys;
}
}
/// <summary>
/// A trivial instance of <c>IResourceReader</c> that does nothing.
/// </summary>
// Needed by the no-arguments constructor.
private static IResourceReader DummyResourceReader = new DummyIResourceReader();
}
/// <summary>
/// A trivial <c>IResourceReader</c> implementation.
/// </summary>
class DummyIResourceReader : IResourceReader {
// Implementation of IDisposable.
void System.IDisposable.Dispose () {
}
// Implementation of IEnumerable.
IEnumerator System.Collections.IEnumerable.GetEnumerator () {
return null;
}
// Implementation of IResourceReader.
void System.Resources.IResourceReader.Close () {
}
IDictionaryEnumerator System.Resources.IResourceReader.GetEnumerator () {
return null;
}
}
}