ICU msg format support with more than one arguments

base/i18n/message_formatter.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_I18N_MESSAGE_FORMATTER_H_
+#define BASE_I18N_MESSAGE_FORMATTER_H_
+
+#include <stdint.h>
+#include <string>
+
+#include "base/i18n/base_i18n_export.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
+#include "third_party/icu/source/common/unicode/uversion.h"
+
+U_NAMESPACE_BEGIN
+class Formattable;
+U_NAMESPACE_END
+
+namespace base {
+
+class Time;
+
+namespace i18n {
+
+class MessageFormatter;
+
+namespace internal {
+
+class BASE_I18N_EXPORT MessageArg {
+ public:
+  MessageArg(const char* s);
+  MessageArg(StringPiece s);
+  MessageArg(const std::string& s);
+  MessageArg(const string16& s);
+  MessageArg(int i);
+  MessageArg(int64_t i);
+  MessageArg(double d);
+  MessageArg(const Time& t);
+  ~MessageArg();
+
+ private:
+  friend class base::i18n::MessageFormatter;
+  MessageArg();
+  // Tests if this argument has a value, and if so increments *count.
+  bool has_value(int* count) const;
+  scoped_ptr<icu::Formattable> formattable;
+  DISALLOW_COPY_AND_ASSIGN(MessageArg);
+};
+
+}  // namespace internal
+
+// Message Formatter with the ICU message format syntax support.
+// It can format strings (UTF-8 and UTF-16), numbers and base::Time with
+// plural, gender and other 'selectors' support. This is handy if you
+// have multiple parameters of differnt types and some of them require
+// plural or gender/selector support.
+//
+// To use this API for locale-sensitive formatting, retrieve a 'message
+// template' in the ICU message format from a message bundle (e.g. with
+// l10n_util::GetStringUTF16()) and pass it to FormatWith{Named,Numbered}Args.
+//
+// MessageFormat specs:
+//   http://icu-project.org/apiref/icu4j/com/ibm/icu/text/MessageFormat.html
+//   http://icu-project.org/apiref/icu4c/classicu_1_1DecimalFormat.html#details
+// Examples:
+//   http://userguide.icu-project.org/formatparse/messages
+//   message_formatter_unittest.cc
+//   go/plurals inside Google.
+//   TODO(jshin): Document this API at sites.chromium.org and add a reference
+//   here.
+
+class BASE_I18N_EXPORT MessageFormatter {
+ public:
+  static string16 FormatWithNamedArgs(
+      StringPiece16 msg,
+      StringPiece name0 = StringPiece(),
+      const internal::MessageArg& arg0 = internal::MessageArg(),
+      StringPiece name1 = StringPiece(),
+      const internal::MessageArg& arg1 = internal::MessageArg(),
+      StringPiece name2 = StringPiece(),
+      const internal::MessageArg& arg2 = internal::MessageArg(),
+      StringPiece name3 = StringPiece(),
+      const internal::MessageArg& arg3 = internal::MessageArg(),
+      StringPiece name4 = StringPiece(),
+      const internal::MessageArg& arg4 = internal::MessageArg(),
+      StringPiece name5 = StringPiece(),
+      const internal::MessageArg& arg5 = internal::MessageArg(),
+      StringPiece name6 = StringPiece(),
+      const internal::MessageArg& arg6 = internal::MessageArg());
+
+  static string16 FormatWithNumberedArgs(
+      StringPiece16 msg,
+      const internal::MessageArg& arg0 = internal::MessageArg(),
+      const internal::MessageArg& arg1 = internal::MessageArg(),
+      const internal::MessageArg& arg2 = internal::MessageArg(),
+      const internal::MessageArg& arg3 = internal::MessageArg(),
+      const internal::MessageArg& arg4 = internal::MessageArg(),
+      const internal::MessageArg& arg5 = internal::MessageArg(),
+      const internal::MessageArg& arg6 = internal::MessageArg());
+
+ private:
+  MessageFormatter() {}
+  DISALLOW_COPY_AND_ASSIGN(MessageFormatter);
+};
+
+}  // namespace i18n
+}  // namespace base
+
+#endif  // BASE_I18N_MESSAGE_FORMATTER_H_