Adding DateTimeFormat class to i18n API.

src/extensions/experimental/datetime-format.cc

+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "datetime-format.h"
+
+#include "i18n-utils.h"
+#include "unicode/dtfmtsym.h"
+#include "unicode/dtptngen.h"
+#include "unicode/locid.h"
+#include "unicode/smpdtfmt.h"
+
+namespace v8 {
+namespace internal {
+
+v8::Persistent<v8::FunctionTemplate> DateTimeFormat::datetime_format_template_;
+
+static icu::DateFormat* CreateDateTimeFormat(v8::Handle<v8::String>,
+                                             v8::Handle<v8::Object>);
+static v8::Handle<v8::Value> GetSymbols(
+    const v8::Arguments&, const icu::UnicodeString*, int32_t,
+    const icu::UnicodeString*, int32_t);
+static v8::Handle<v8::Value> ThrowUnexpectedObjectError();
+
+icu::SimpleDateFormat* DateTimeFormat::UnpackDateTimeFormat(
+    v8::Handle<v8::Object> obj) {
+  if (datetime_format_template_->HasInstance(obj)) {
+    return static_cast<icu::SimpleDateFormat*>(
+        obj->GetPointerFromInternalField(0));
+  }
+
+  return NULL;
+}
+
+void DateTimeFormat::DeleteDateTimeFormat(v8::Persistent<v8::Value> object,
+                                          void* param) {
+  v8::Persistent<v8::Object> persistent_object =
+      v8::Persistent<v8::Object>::Cast(object);
+
+  // First delete the hidden C++ object.
+  // Unpacking should never return NULL here. That would only happen if
+  // this method is used as the weak callback for persistent handles not
+  // pointing to a date time formatter.
+  delete UnpackDateTimeFormat(persistent_object);
+
+  // Then dispose of the persistent handle to JS object.
+  persistent_object.Dispose();
+}
+
+v8::Handle<v8::Value> DateTimeFormat::Format(const v8::Arguments& args) {
+  v8::HandleScope handle_scope;
+
+  double millis = 0.0;
+  if (args.Length() != 1 || !args[0]->IsDate()) {
+    // Create a new date.
+    v8::TryCatch try_catch;
+    v8::Local<v8::Script> date_script =
+        v8::Script::Compile(v8::String::New("eval('new Date()')"));
+    millis = date_script->Run()->NumberValue();
+    if (try_catch.HasCaught()) {
+      return try_catch.ReThrow();
+    }
+  } else {
+    millis = v8::Date::Cast(*args[0])->NumberValue();
+  }
+
+  icu::SimpleDateFormat* date_format = UnpackDateTimeFormat(args.Holder());
+  if (!date_format) {
+    return ThrowUnexpectedObjectError();
+  }
+
+  icu::UnicodeString result;
+  date_format->format(millis, result);
+
+  return v8::String::New(
+      reinterpret_cast<const uint16_t*>(result.getBuffer()), result.length());
+}
+
+v8::Handle<v8::Value> DateTimeFormat::GetMonths(const v8::Arguments& args) {
+  icu::SimpleDateFormat* date_format = UnpackDateTimeFormat(args.Holder());
+  if (!date_format) {
+    return ThrowUnexpectedObjectError();
+  }
+
+  const icu::DateFormatSymbols* symbols = date_format->getDateFormatSymbols();
+
+  int32_t abbrev_count;
+  const icu::UnicodeString* abbrev = symbols->getShortMonths(abbrev_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getMonths(wide_count);

[jungshik at Google, 2011/05/19 18:24:05]

Again, how about 'narrow'? 

More importantly, using getMonths/getShortMonths method, you're returning month
names of 'context = format' instead of 'context=stand-alone'. (see the ICU
source code ( i18n/dtfmtsym.cpp). ICU documentation needs to make it clear. I've
filed a bug against ICU ( http://bugs.icu-project.org/trac/ticket/8587)

Please, use a version of getMonths accepting 'context' and 'width' : 

getMonths(int32_t & 	count, DtContextType 	context, DtWidthType) 

The same is true of GetWeekDays

[Nebojša Ćirić, 2011/05/19 20:44:41]

Narrow was not part of the proposed standard, but I added support for it (now).

Switched to getMonths(, DtContext...) methods.

On 2011/05/19 18:24:05, Jungshik Shin wrote:

+
+  return GetSymbols(args, abbrev, abbrev_count, wide, wide_count);
+}
+
+v8::Handle<v8::Value> DateTimeFormat::GetWeekdays(const v8::Arguments& args) {
+  icu::SimpleDateFormat* date_format = UnpackDateTimeFormat(args.Holder());
+  if (!date_format) {
+    ThrowUnexpectedObjectError();
+  }
+
+  const icu::DateFormatSymbols* symbols = date_format->getDateFormatSymbols();
+
+  int32_t abbrev_count;
+  const icu::UnicodeString* abbrev = symbols->getShortWeekdays(abbrev_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getWeekdays(wide_count);
+
+  // getXXXWeekdays always returns 8 elements.
+  CHECK_EQ(8, abbrev_count);
+  CHECK_EQ(8, wide_count);
+
+  // ICU documentation says we should ignore element 0 of the returned array.
+  return GetSymbols(
+      args, abbrev + 1, abbrev_count -1 , wide + 1, wide_count - 1);
+}
+
+v8::Handle<v8::Value> DateTimeFormat::GetEras(const v8::Arguments& args) {
+  icu::SimpleDateFormat* date_format = UnpackDateTimeFormat(args.Holder());
+  if (!date_format) {
+    return ThrowUnexpectedObjectError();
+  }
+
+  const icu::DateFormatSymbols* symbols = date_format->getDateFormatSymbols();
+
+  int32_t abbrev_count;
+  const icu::UnicodeString* abbrev = symbols->getEras(abbrev_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getEraNames(wide_count);
+
+  return GetSymbols(args, abbrev, abbrev_count, wide, wide_count);
+}
+
+v8::Handle<v8::Value> DateTimeFormat::GetAmPm(const v8::Arguments& args) {
+  icu::SimpleDateFormat* date_format = UnpackDateTimeFormat(args.Holder());
+  if (!date_format) {
+    return ThrowUnexpectedObjectError();
+  }
+
+  const icu::DateFormatSymbols* symbols = date_format->getDateFormatSymbols();
+
+  int32_t abbrev_count;
+  const icu::UnicodeString* abbrev = symbols->getAmPmStrings(abbrev_count);
+  int32_t wide_count = abbrev_count;
+  const icu::UnicodeString* wide = abbrev;
+
+  return GetSymbols(args, abbrev, abbrev_count, wide, wide_count);
+}
+
+v8::Handle<v8::Value> DateTimeFormat::JSDateTimeFormat(
+    const v8::Arguments& args) {
+  v8::HandleScope handle_scope;
+
+  ASSERT_EQ(2, args.Length());
+  // LanguageID string.
+  ASSERT(args[0]->IsString());
+  // Settings object.
+  ASSERT(args[1]->IsObject());
+
+  icu::SimpleDateFormat* date_format = static_cast<icu::SimpleDateFormat*>(
+      CreateDateTimeFormat(args[0]->ToString(), args[1]->ToObject()));
+
+  if (datetime_format_template_.IsEmpty()) {
+    v8::Local<v8::FunctionTemplate> raw_template(v8::FunctionTemplate::New());
+
+    raw_template->SetClassName(v8::String::New("v8Locale.DateTimeFormat"));
+
+    // Define internal field count on instance template.
+    v8::Local<v8::ObjectTemplate> object_template =
+        raw_template->InstanceTemplate();
+
+    // Set aside internal field for icu date time formatter.
+    object_template->SetInternalFieldCount(1);
+
+    // Define all of the prototype methods on prototype template.
+    v8::Local<v8::ObjectTemplate> proto = raw_template->PrototypeTemplate();
+    proto->Set(v8::String::New("format"),
+               v8::FunctionTemplate::New(Format));
+    proto->Set(v8::String::New("getMonths"),
+               v8::FunctionTemplate::New(GetMonths));
+    proto->Set(v8::String::New("getWeekdays"),
+               v8::FunctionTemplate::New(GetWeekdays));
+    proto->Set(v8::String::New("getEras"),
+               v8::FunctionTemplate::New(GetEras));
+    proto->Set(v8::String::New("getAmPm"),
+               v8::FunctionTemplate::New(GetAmPm));
+
+    datetime_format_template_ =
+        v8::Persistent<v8::FunctionTemplate>::New(raw_template);
+  }
+
+  // Create an empty object wrapper.
+  v8::Local<v8::Object> local_object =
+      datetime_format_template_->GetFunction()->NewInstance();
+  v8::Persistent<v8::Object> wrapper =
+      v8::Persistent<v8::Object>::New(local_object);
+
+  // Set date time formatter as internal field of the resulting JS object.
+  wrapper->SetPointerInInternalField(0, date_format);
+
+  // Set resolved pattern in options.pattern.
+  icu::UnicodeString pattern;
+  date_format->toPattern(pattern);
+  v8::Local<v8::Object> options = v8::Object::New();
+  options->Set(v8::String::New("pattern"),
+               v8::String::New(reinterpret_cast<const uint16_t*>(
+                   pattern.getBuffer()), pattern.length()));
+  wrapper->Set(v8::String::New("options"), options);
+
+  // Make object handle weak so we can delete iterator once GC kicks in.
+  wrapper.MakeWeak(NULL, DeleteDateTimeFormat);
+
+  return wrapper;
+}
+
+// Returns SimpleDateFormat.
+static icu::DateFormat* CreateDateTimeFormat(
+    v8::Handle<v8::String> locale, v8::Handle<v8::Object> settings) {
+  v8::HandleScope handle_scope;
+
+  v8::String::AsciiValue ascii_locale(locale);
+  icu::Locale icu_locale(*ascii_locale);
+
+  // Make formatter from skeleton.
+  icu::SimpleDateFormat* date_format = NULL;
+  UErrorCode status = U_ZERO_ERROR;
+  icu::UnicodeString skeleton;
+  if (I18NUtils::ExtractStringSetting(settings, "skeleton", &skeleton)) {
+    v8::Local<icu::DateTimePatternGenerator> generator(
+        icu::DateTimePatternGenerator::createInstance(icu_locale, status));
+    icu::UnicodeString pattern =
+        generator->getBestPattern(skeleton, status);
+
+    date_format = new icu::SimpleDateFormat(pattern, icu_locale, status);
+    if (U_SUCCESS(status)) {
+      return date_format;
+    } else {
+      delete date_format;
+    }
+  }
+
+  // Extract date type and time type from settings.
+  icu::UnicodeString short_dt = icu::UnicodeString::fromUTF8("short");

[jungshik at Google, 2011/05/19 18:24:05]

short_dt("short", -1, US_INV);


is more succinct. 

BTW, wouldn't you just go ahead to support all the types - full, long, medium
and short ?  Perhaps, those not yet standardized can have "v8" prefixes. 

[Nebojša Ćirić, 2011/05/19 20:44:41]

I support all types now. We should state in proposal that those names should be
reserved.

Also, I don't really like , -1, US_INV part of that method. It's not readable
vs. fromUTF8. It's gone anyways.

On 2011/05/19 18:24:05, Jungshik Shin wrote:

+  icu::UnicodeString date_type;
+  icu::DateFormat::EStyle date_style = icu::DateFormat::kNone;
+  if (I18NUtils::ExtractStringSetting(settings, "dateType", &date_type)) {
+    if (date_type == short_dt) {
+      date_style = icu::DateFormat::kShort;
+    } else {
+      date_style = icu::DateFormat::kLong;
+    }
+  }
+
+  icu::UnicodeString time_type;
+  icu::DateFormat::EStyle time_style = icu::DateFormat::kNone;
+  if (I18NUtils::ExtractStringSetting(settings, "timeType", &time_type)) {
+    if (time_type == short_dt) {
+      time_style = icu::DateFormat::kShort;
+    } else {
+      time_style = icu::DateFormat::kMedium;
+    }
+  }
+
+  // Try all combinations of date/time types.
+  if (date_style == icu::DateFormat::kNone &&
+      time_style == icu::DateFormat::kNone) {
+    // Return default short date, short
+    return icu::DateFormat::createDateTimeInstance(
+        icu::DateFormat::kShort, icu::DateFormat::kShort, icu_locale);
+  } else if (date_style != icu::DateFormat::kNone &&
+             time_style != icu::DateFormat::kNone) {
+    return icu::DateFormat::createDateTimeInstance(
+        date_style, time_style, icu_locale);
+  } else if (date_style != icu::DateFormat::kNone) {
+    return icu::DateFormat::createDateInstance(date_style, icu_locale);
+  } else {
+    // time_style != icu::DateFormat::kNone
+    return icu::DateFormat::createTimeInstance(time_style, icu_locale);
+  }
+}
+
+// Creates a v8::Array of abbrev or wide symbols.
+static v8::Handle<v8::Value> GetSymbols(const v8::Arguments& args,
+                                        const icu::UnicodeString* abbrev,
+                                        int32_t abbrev_count,
+                                        const icu::UnicodeString* wide,
+                                        int32_t wide_count) {
+  v8::HandleScope handle_scope;
+
+  const icu::UnicodeString* result = wide;
+  int32_t count = wide_count;
+
+  if (args.Length() == 1 && args[0]->IsString()) {
+    v8::String::AsciiValue ascii_value(args[0]);
+    if (strcmp(*ascii_value, "abbreviated") == 0) {
+      result = abbrev;
+      count = abbrev_count;
+    }
+  }
+
+  v8::Handle<v8::Array> symbols = v8::Array::New();
+  for (int32_t i = 0; i < count; ++i) {
+    symbols->Set(i, v8::String::New(
+        reinterpret_cast<const uint16_t*>(result[i].getBuffer()),
+        result[i].length()));
+  }
+
+  return handle_scope.Close(symbols);
+}
+
+// Throws a JavaScript exception.
+static v8::Handle<v8::Value> ThrowUnexpectedObjectError() {
+  // Returns undefined, and schedules an exception to be thrown.
+  return v8::ThrowException(v8::Exception::Error(
+      v8::String::New("DateTimeFormat method called on an object "
+                      "that is not a DateTimeFormat.")));
+}
+
+} }  // namespace v8::internal