Adds facilities for extracting Intl.message calls and generating code from translations

pkg/intl/test/message_extraction/sample_with_messages.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/**
+ * This is a program with various [Intl.message] messages. It just prints
+ * all of them, and is used for testing of message extraction, translation,
+ * and code generation.
+ */
+library sample;
+
+import "package:intl/intl.dart";
+import "package:intl/message_lookup_by_library.dart";
+import "dart:async";
+import "package:intl/src/intl_helpers.dart";
+import "messages_all.dart";
+
+part 'part_of_sample_with_messages.dart';
+
+message1() => Intl.message("This is a message", name: 'message1', desc: 'foo' );
+
+message2(x) => Intl.message("Another message with parameter $x",
+    name: 'message2', desc: 'Description 2', args: [x]);
+
+multiLine() => Intl.message("This "
+    "string "
+    "extends "
+    "across "
+    "multiple "
+    "lines.",
+    name: "multiLine");
+
+types(int a, String b, List c) => Intl.message("$a, $b, $c", name: 'types',
+    args: [a, b, c]);
+
+alwaysAccented() =>
+    Intl.message("This string is always translated", locale: 'fr',
+        name: 'alwaysTranslated');
+
+trickyInterpolation(s) =>
+    Intl.message("Interpolation is tricky when it ends a sentence like ${s}.",

[Emily Fortuna, 2013/03/13 18:54:43]

how is this different from message2?

[Alan Knight, 2013/03/14 17:49:05]

The interpolation is ${s} rather than just $x and is followed by a period. At
one point I was thinking that "$x.y" was ambiguous as an interpolation and we
needed to allow "${x}.y" but I don't think that's true, so the only interesting
thing is the curly braces around the expression, and that it's followed by
something else.

Added comments for the test sentences to say what they're exercising.

+        name: 'trickyInterpolation', args: [s]);
+
+leadingQuotes() => Intl.message("\"So-called\"", name: 'leadingQuotes');
+
+originalNotInBMP() => Intl.message("Ancient Greek hangman characters: 𐅆𐅇.",

[Emily Fortuna, 2013/03/13 18:54:43]

bmp?

[Alan Knight, 2013/03/14 17:49:05]

Basic Multilingual Plane. Characters that fit in UTF-16. So this sentence
contains characters that require multiple UTF-16 code units. Added a comment
saying what BMP is.

+    name: "originalNotInBMP");
+
+notAlwaysTranslated() => Intl.message("This is missing some translations",
+    name: "notAlwaysTranslated");
+
+var someString = "No, it has to be a literal string";
+noVariables() => Intl.message(someString, name: "noVariables");
+
+escapable() => Intl.message("Escapable characters here: ", name: "escapable");
+
+printStuff(Intl locale) {
+
+  // Use a name that's not a literal so this will get skipped. Then we have
+  // a name that's not in the original but we include it in the French
+  // translation. Because it's not in the original it shouldn't get included
+  // in the generated catalog and shouldn't get translated.
+  if (locale.locale == 'fr') {
+    var badName = "thisNameIsNotInTheOriginal";
+    var notInOriginal = Intl.message("foo", name: badName);
+    if (notInOriginal != "foo") {
+      throw "You shouldn't be able to introduce a new message in a translation";
+    }
+  }
+
+  var messageVariable = (a, b, c) => Intl.message(
+      "Characters that need escaping, e.g slashes \\ dollars \${ (curly braces "
+      "are ok) and xml reserved characters <& and quotes \" "
+      "parameters $a, $b, and $c",
+      name: 'message3',
+      args: [a, b, c]);
+
+  print("-------------------------------------------");
+  print("Printing messages for ${locale.locale}");
+  Intl.withLocale(locale.locale, () {
+    print(message1());

[Emily Fortuna, 2013/03/13 18:54:43]

why print here instead of using expect?

[Alan Knight, 2013/03/14 17:49:05]

I can't directly expect a constant here, because it's being run repeatedly with
multiple different locales. But I also wanted to keep the standalone program
being internationalized separate from the test code. So this isn't a test at
all, and is run from another program that is a test, so it prints and the other
program consumes its stdout.

Running this program as the test itself would be tricky, because this program
won't even compile until the code generation step has been done, because it
imports messages_all.dart, which doesn't exist. We could run it as the last
phase of the test, but then how do we synchronize its expects with the other
program that's doing the extraction and code generation?

+    print(message2("hello"));
+    print(messageVariable(1,2,3));
+    print(multiLine());
+    print(types(1, "b", ["c", "d"]));
+    print(leadingQuotes());
+    print(alwaysAccented());
+    print(trickyInterpolation("this"));
+    var thing = new YouveGotMessages();
+    print(thing.method());
+    print(thing.nonLambda());
+    var x = YouveGotMessages.staticMessage();
+    print(YouveGotMessages.staticMessage());
+    print(notAlwaysTranslated());
+    print(originalNotInBMP());
+    // TODO(alanknight): Support named arguments.
+//    print(thing.namedArgs(thing: 'well...'));
+    // TODO(alanknight): Support plurals. Do we need to consider changing
+    // the form so as not to have a difficult to validate interpolation
+    // in our translation output?
+//    print(thing.plurals(1));
+//    print(thing.plurals(2));
+    print(escapable());
+  });
+}
+
+var localeToUse = 'en_US';
+
+main() {
+  var fr = new Intl("fr");
+  var english = new Intl("en_US");
+  var de = new Intl("de_DE");
+  initializeMessages(fr.locale).then((_) => printStuff(fr));
+  initializeMessages(de.locale).then((_) => printStuff(de));
+  printStuff(english);
+}