base/i18n/message_formatter.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_I18N_MESSAGE_FORMATTER_H_
   6 #define BASE_I18N_MESSAGE_FORMATTER_H_
   7
   8 #include <stdint.h>
   9 #include <string>
  10
  11 #include "base/i18n/base_i18n_export.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/strings/string16.h"
  14 #include "base/strings/string_piece.h"
  15 #include "third_party/icu/source/common/unicode/uversion.h"
  16
  17 U_NAMESPACE_BEGIN
  18 class Formattable;
  19 U_NAMESPACE_END
  20
  21 namespace base {
  22
  23 class Time;
  24
  25 namespace i18n {
  26
  27 class MessageFormatter;
  28
  29 namespace internal {
  30
  31 class BASE_I18N_EXPORT MessageArg {
  32  public:
  33   MessageArg(const char* s);
  34   MessageArg(StringPiece s);
  35   MessageArg(const std::string& s);
  36   MessageArg(const string16& s);
  37   MessageArg(int i);
  38   MessageArg(int64_t i);
  39   MessageArg(double d);
  40   MessageArg(const Time& t);
  41   ~MessageArg();
  42
  43  private:
  44   friend class base::i18n::MessageFormatter;
  45   MessageArg();
  46   // Tests if this argument has a value, and if so increments *count.
  47   bool has_value(int* count) const;
  48   scoped_ptr<icu::Formattable> formattable;
  49   DISALLOW_COPY_AND_ASSIGN(MessageArg);
  50 };
  51
  52 }  // namespace internal
  53
  54 // Message Formatter with the ICU message format syntax support.
  55 // It can format strings (UTF-8 and UTF-16), numbers and base::Time with
  56 // plural, gender and other 'selectors' support. This is handy if you
  57 // have multiple parameters of differnt types and some of them require
  58 // plural or gender/selector support.
  59 //
  60 // To use this API for locale-sensitive formatting, retrieve a 'message
  61 // template' in the ICU message format from a message bundle (e.g. with
  62 // l10n_util::GetStringUTF16()) and pass it to FormatWith{Named,Numbered}Args.
  63 //
  64 // MessageFormat specs:
  65 //   http://icu-project.org/apiref/icu4j/com/ibm/icu/text/MessageFormat.html
  66 //   http://icu-project.org/apiref/icu4c/classicu_1_1DecimalFormat.html#details
  67 // Examples:
  68 //   http://userguide.icu-project.org/formatparse/messages
  69 //   message_formatter_unittest.cc
  70 //   go/plurals inside Google.
  71 //   TODO(jshin): Document this API at sites.chromium.org and add a reference
  72 //   here.
  73
  74 class BASE_I18N_EXPORT MessageFormatter {
  75  public:
  76   static string16 FormatWithNamedArgs(
  77       StringPiece16 msg,
  78       StringPiece name0 = StringPiece(),
  79       const internal::MessageArg& arg0 = internal::MessageArg(),
  80       StringPiece name1 = StringPiece(),
  81       const internal::MessageArg& arg1 = internal::MessageArg(),
  82       StringPiece name2 = StringPiece(),
  83       const internal::MessageArg& arg2 = internal::MessageArg(),
  84       StringPiece name3 = StringPiece(),
  85       const internal::MessageArg& arg3 = internal::MessageArg(),
  86       StringPiece name4 = StringPiece(),
  87       const internal::MessageArg& arg4 = internal::MessageArg(),
  88       StringPiece name5 = StringPiece(),
  89       const internal::MessageArg& arg5 = internal::MessageArg(),
  90       StringPiece name6 = StringPiece(),
  91       const internal::MessageArg& arg6 = internal::MessageArg());
  92
  93   static string16 FormatWithNumberedArgs(
  94       StringPiece16 msg,
  95       const internal::MessageArg& arg0 = internal::MessageArg(),
  96       const internal::MessageArg& arg1 = internal::MessageArg(),
  97       const internal::MessageArg& arg2 = internal::MessageArg(),
  98       const internal::MessageArg& arg3 = internal::MessageArg(),
  99       const internal::MessageArg& arg4 = internal::MessageArg(),
 100       const internal::MessageArg& arg5 = internal::MessageArg(),
 101       const internal::MessageArg& arg6 = internal::MessageArg());
 102
 103  private:
 104   MessageFormatter() {}
 105   DISALLOW_COPY_AND_ASSIGN(MessageFormatter);
 106 };
 107
 108 }  // namespace i18n
 109 }  // namespace base
 110
 111 #endif  // BASE_I18N_MESSAGE_FORMATTER_H_