Add utility function to determine if a locale is valid syntax; this will

be used by the TTS extension API. Moved some locale utility functions from
extension_l10n_util to l10n_util.

BUG=none
TEST=Adds new unit test

Review URL: http://codereview.chromium.org/5643002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@69004 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 177 insertions, 0 deletions

diff --git a/app/l10n_util.cc b/app/l10n_util.cc
index 148151d..4d6b8b9 100644
--- a/app/l10n_util.cc
+++ b/app/l10n_util.cc
@@ -29,6 +29,7 @@
 #include "build/build_config.h"
 #include "gfx/canvas.h"
 #include "unicode/rbbi.h"
+#include "unicode/uloc.h"
 
 #if defined(OS_MACOSX)
 #include "app/l10n_util_mac.h"
@@ -475,6 +476,97 @@ string16 GetDisplayNameForLocale(const std::string& locale,
   return display_name;
 }
 
+std::string NormalizeLocale(const std::string& locale) {
+  std::string normalized_locale(locale);
+  std::replace(normalized_locale.begin(), normalized_locale.end(), '-', '_');
+
+  return normalized_locale;
+}
+
+void GetParentLocales(const std::string& current_locale,
+                      std::vector<std::string>* parent_locales) {
+  std::string locale(NormalizeLocale(current_locale));
+
+  const int kNameCapacity = 256;
+  char parent[kNameCapacity];
+  base::strlcpy(parent, locale.c_str(), kNameCapacity);
+  parent_locales->push_back(parent);
+  UErrorCode err = U_ZERO_ERROR;
+  while (uloc_getParent(parent, parent, kNameCapacity, &err) > 0) {
+    if (U_FAILURE(err))
+      break;
+    parent_locales->push_back(parent);
+  }
+}
+
+bool IsValidLocaleSyntax(const std::string& locale) {
+  // Check that the length is plausible.
+  if (locale.size() < 2 || locale.size() >= ULOC_FULLNAME_CAPACITY)
+    return false;
+
+  // Strip off the part after an '@' sign, which might contain keywords,
+  // as in en_IE@currency=IEP or fr@collation=phonebook;calendar=islamic-civil.
+  // We don't validate that part much, just check that there's at least one
+  // equals sign in a plausible place.
+  std::string prefix = locale;
+  if (locale.find("@") != std::string::npos) {
+    size_t split_point = locale.find("@");
+    std::string keywords = locale.substr(split_point + 1);
+    prefix = locale.substr(0, split_point);
+
+    size_t equals_loc = keywords.find("=");
+    if (equals_loc == std::string::npos ||
+        equals_loc < 1 || equals_loc > keywords.size() - 2)
+      return false;
+  }
+
+  // Check that all characters before the at-sign are alphanumeric, hyphen,
+  // or underscore.
+  for (size_t i = 0; i < prefix.size(); i++) {
+    char ch = prefix[i];
+    if (!IsAsciiAlpha(ch) && !IsAsciiDigit(ch) && ch != '-' && ch != '_')
+      return false;
+  }
+
+  // Check that the initial token (before the first hyphen/underscore)
+  // is 1 - 3 alphabetical characters (a language tag).
+  for (size_t i = 0; i < prefix.size(); i++) {
+    char ch = prefix[i];
+    if (ch == '-' || ch == '_') {
+      if (i < 1 || i > 3)
+        return false;
+      break;
+    }
+    if (!IsAsciiAlpha(ch))
+      return false;
+  }
+
+  // Check that the all tokens after the initial token are 1 - 8 characters.
+  // (Tokenize/StringTokenizer don't work here, they collapse multiple
+  // delimiters into one.)
+  int token_len = 0;
+  int token_index = 0;
+  for (size_t i = 0; i < prefix.size(); i++) {
+    char ch = prefix[i];
+    if (ch == '-' || ch == '_') {
+      if (token_index > 0 && (token_len < 1 || token_len > 8)) {
+        return false;
+      }
+      token_index++;
+      token_len = 0;
+    } else {
+      token_len++;
+    }
+  }
+  if (token_index == 0 && (token_len < 1 || token_len > 3)) {
+    return false;
+  } else if (token_len < 1 || token_len > 8) {
+    return false;
+  }
+
+  return true;
+}
+
 std::wstring GetString(int message_id) {
   return UTF16ToWide(GetStringUTF16(message_id));
 }
diff --git a/app/l10n_util.h b/app/l10n_util.h
index a1519b5..a71c21c 100644
--- a/app/l10n_util.h
+++ b/app/l10n_util.h
@@ -56,6 +56,25 @@ string16 GetDisplayNameForLocale(const std::string& locale,
                                  const std::string& display_locale,
                                  bool is_for_ui);
 
+// Converts all - into _, to be consistent with ICU and file system names.
+std::string NormalizeLocale(const std::string& locale);
+
+// Produce a vector of parent locales for given locale.
+// It includes the current locale in the result.
+// sr_Cyrl_RS generates sr_Cyrl_RS, sr_Cyrl and sr.
+void GetParentLocales(const std::string& current_locale,
+                      std::vector<std::string>* parent_locales);
+
+// Checks if a string is plausibly a syntactically-valid locale string,
+// for cases where we want the valid input to be a locale string such as
+// 'en', 'pt-BR', 'fil', 'es-419', 'zh-Hans-CN', 'i-klingon' or
+// 'de_DE@collation=phonebook', but we don't want to limit it to
+// locales that Chrome actually knows about, so 'xx-YY' should be
+// accepted, but 'z', 'German', 'en-$1', or 'abcd-1234' should not.
+// Case-insensitive. Based on BCP 47, see:
+//   http://unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers
+bool IsValidLocaleSyntax(const std::string& locale);
+
 //
 // Mac Note: See l10n_util_mac.h for some NSString versions and other support.
 //
diff --git a/app/l10n_util_unittest.cc b/app/l10n_util_unittest.cc
index fa4cc24..786f1f6 100644
--- a/app/l10n_util_unittest.cc
+++ b/app/l10n_util_unittest.cc
@@ -325,3 +325,69 @@ TEST_F(L10nUtilTest, LocaleDisplayName) {
   result = l10n_util::GetDisplayNameForLocale("es-419", "en", false);
   EXPECT_EQ(result, ASCIIToUTF16("Spanish (Latin America and the Caribbean)"));
 }
+
+TEST_F(L10nUtilTest, GetParentLocales) {
+  std::vector<std::string> locales;
+  const std::string top_locale("sr_Cyrl_RS");
+  l10n_util::GetParentLocales(top_locale, &locales);
+
+  ASSERT_EQ(3U, locales.size());
+  EXPECT_EQ("sr_Cyrl_RS", locales[0]);
+  EXPECT_EQ("sr_Cyrl", locales[1]);
+  EXPECT_EQ("sr", locales[2]);
+}
+
+TEST_F(L10nUtilTest, IsValidLocaleSyntax) {
+  // Test valid locales.
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("fr"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("de"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("pt"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("fil"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("haw"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en-US"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en_US"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en_GB"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("pt-BR"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh_CN"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh_Hans"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh_Hans_CN"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh_Hant"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zh_Hant_TW"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("fr_CA"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("i-klingon"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("es-419"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en_IE_PREEURO"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en_IE_u_cu_IEP"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("en_IE@currency=IEP"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("fr@x=y"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax("zn_CN@foo=bar"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax(
+      "fr@collation=phonebook;calendar=islamic-civil"));
+  EXPECT_EQ(true, l10n_util::IsValidLocaleSyntax(
+      "sr_Latn_RS_REVISED@currency=USD"));
+
+  // Test invalid locales.
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax(""));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("x"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("12"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("456"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("a1"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("enUS"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("zhcn"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en.US"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en#US"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("-en-US"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en-US-"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("123-en-US"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("Latin"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("German"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("pt--BR"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("sl-macedonia"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("@"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en-US@"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en-US@x"));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en-US@x="));
+  EXPECT_EQ(false, l10n_util::IsValidLocaleSyntax("en-US@=y"));
+}