1 // Copyright 2015 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef BASE_I18N_MESSAGE_FORMATTER_H_
6 #define BASE_I18N_MESSAGE_FORMATTER_H_
13 #include "base/i18n/base_i18n_export.h"
14 #include "base/strings/string_piece.h"
15 #include "third_party/icu/source/common/unicode/uversion.h"
27 class MessageFormatter;
31 class BASE_I18N_EXPORT MessageArg {
33 MessageArg(const char* s);
34 MessageArg(StringPiece s);
35 MessageArg(const std::string& s);
36 MessageArg(const std::u16string& s);
38 MessageArg(int64_t i);
40 MessageArg(const Time& t);
42 MessageArg(const MessageArg&) = delete;
43 MessageArg& operator=(const MessageArg&) = delete;
48 friend class base::i18n::MessageFormatter;
50 // Tests if this argument has a value, and if so increments *count.
51 bool has_value(int* count) const;
52 std::unique_ptr<icu::Formattable> formattable;
55 } // namespace internal
57 // Message Formatter with the ICU message format syntax support.
58 // It can format strings (UTF-8 and UTF-16), numbers and base::Time with
59 // plural, gender and other 'selectors' support. This is handy if you
60 // have multiple parameters of differnt types and some of them require
61 // plural or gender/selector support.
63 // To use this API for locale-sensitive formatting, retrieve a 'message
64 // template' in the ICU message format from a message bundle (e.g. with
65 // l10n_util::GetStringUTF16()) and pass it to FormatWith{Named,Numbered}Args.
67 // MessageFormat specs:
68 // http://icu-project.org/apiref/icu4j/com/ibm/icu/text/MessageFormat.html
69 // http://icu-project.org/apiref/icu4c/classicu_1_1DecimalFormat.html#details
71 // http://userguide.icu-project.org/formatparse/messages
72 // message_formatter_unittest.cc
73 // go/plurals inside Google.
74 // TODO(jshin): Document this API in md format docs.
76 // When plural/select/gender is used along with other format specifiers such
77 // as date or number, plural/select/gender should be at the top level. It's
78 // not an ICU restriction but a constraint imposed by Google's translation
79 // infrastructure. Message A does not work. It must be revised to Message B.
82 // Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph>
83 // by {1, plural, =1{a user} other{# users}}
87 // =1{Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph>
89 // other{Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph>
92 class BASE_I18N_EXPORT MessageFormatter {
94 MessageFormatter() = delete;
95 MessageFormatter(const MessageFormatter&) = delete;
96 MessageFormatter& operator=(const MessageFormatter&) = delete;
98 static std::u16string FormatWithNamedArgs(
100 StringPiece name0 = StringPiece(),
101 const internal::MessageArg& arg0 = internal::MessageArg(),
102 StringPiece name1 = StringPiece(),
103 const internal::MessageArg& arg1 = internal::MessageArg(),
104 StringPiece name2 = StringPiece(),
105 const internal::MessageArg& arg2 = internal::MessageArg(),
106 StringPiece name3 = StringPiece(),
107 const internal::MessageArg& arg3 = internal::MessageArg(),
108 StringPiece name4 = StringPiece(),
109 const internal::MessageArg& arg4 = internal::MessageArg(),
110 StringPiece name5 = StringPiece(),
111 const internal::MessageArg& arg5 = internal::MessageArg(),
112 StringPiece name6 = StringPiece(),
113 const internal::MessageArg& arg6 = internal::MessageArg());
115 static std::u16string FormatWithNumberedArgs(
117 const internal::MessageArg& arg0 = internal::MessageArg(),
118 const internal::MessageArg& arg1 = internal::MessageArg(),
119 const internal::MessageArg& arg2 = internal::MessageArg(),
120 const internal::MessageArg& arg3 = internal::MessageArg(),
121 const internal::MessageArg& arg4 = internal::MessageArg(),
122 const internal::MessageArg& arg5 = internal::MessageArg(),
123 const internal::MessageArg& arg6 = internal::MessageArg());
129 #endif // BASE_I18N_MESSAGE_FORMATTER_H_