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::SimpleDateFormat* CreateDateTimeFormat(v8::Handle<v8::String>,
+                                                   v8::Handle<v8::String>);
+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.
+    millis = v8::Script::Compile(v8::String::New("eval('new Date()')"))->Run()

[Mads Ager (chromium), 2011/05/16 07:20:52]

Since we don't have a Date::New() method not taking a double this is the right
way to get the current date as a date object. I would split this over a couple
of lines with named variables instead of having one big line.

More seriously, creating a date can throw an exception, you need to handle that
here. Consider the case where a user overwrites Date:

function Date() { throw 42; }

[Nebojša Ćirić, 2011/05/17 20:40:37]

Done.

+        ->NumberValue();
+  } 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 narrow_count;
+  const icu::UnicodeString* narrow = symbols->getShortMonths(narrow_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getMonths(wide_count);
+
+  return GetSymbols(args, narrow, narrow_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 narrow_count;
+  const icu::UnicodeString* narrow = symbols->getShortWeekdays(narrow_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getWeekdays(wide_count);
+
+  // getXXXWeekdays always returns 8 elements.
+  CHECK_EQ(8, narrow_count);
+  CHECK_EQ(8, wide_count);
+
+  // ICU documentation says we should ignore element 0 of the returned array.
+  return GetSymbols(
+      args, narrow + 1, narrow_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 narrow_count;
+  const icu::UnicodeString* narrow = symbols->getNarrowEras(narrow_count);
+  int32_t wide_count;
+  const icu::UnicodeString* wide = symbols->getEraNames(wide_count);
+
+  return GetSymbols(args, narrow, narrow_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 narrow_count;
+  const icu::UnicodeString* narrow = symbols->getAmPmStrings(narrow_count);
+  int32_t wide_count = narrow_count;
+  const icu::UnicodeString* wide = narrow;
+
+  return GetSymbols(args, narrow, narrow_count, wide, wide_count);
+}
+
+v8::Handle<v8::Value> DateTimeFormat::JSDateTimeFormat(
+    const v8::Arguments& args) {
+  v8::HandleScope handle_scope;
+
+  icu::SimpleDateFormat* date_format =
+      CreateDateTimeFormat(args[0]->ToString(), args[1]->ToString());

[Mads Ager (chromium), 2011/05/16 07:20:52]

String conversions can throw exceptions. If you expect the arguments to be
strings you should check before converting. If not, you need to check for
exceptions and deal with the exception case.

 V8 version 3.3.7 (candidate)
 > var o = { valueOf: function() { throw 42; } }
 > o + ''

The string conversion of 'o' throws.

+
+  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::SimpleDateFormat* CreateDateTimeFormat(
+    v8::Handle<v8::String> locale, v8::Handle<v8::String> skeleton) {
+  v8::HandleScope handle_scope;
+
+  v8::String::AsciiValue ascii_locale(locale);
+  icu::Locale icu_locale(*ascii_locale);
+
+  v8::String::Value text_value(skeleton);
+  icu::UnicodeString skeleton_string(
+      reinterpret_cast<const UChar*>(*text_value), text_value.length());
+
+  UErrorCode status = U_ZERO_ERROR;
+  v8::Local<icu::DateTimePatternGenerator> generator(
+      icu::DateTimePatternGenerator::createInstance(icu_locale, status));
+  icu::UnicodeString pattern =
+      generator->getBestPattern(skeleton_string, status);
+
+  icu::SimpleDateFormat* date_format =
+      new icu::SimpleDateFormat(pattern, icu_locale, status);
+  if (U_SUCCESS(status)) {
+    return date_format;
+  } else {
+    delete date_format;
+    status = U_ZERO_ERROR;
+    return new icu::SimpleDateFormat(status);
+  }
+}
+
+// Creates a v8::Array of narrow or wide symbols.
+static v8::Handle<v8::Value> GetSymbols(const v8::Arguments& args,
+                                        const icu::UnicodeString* narrow,
+                                        int32_t narrow_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, "narrow") == 0) {
+      result = narrow;
+      count = narrow_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