Intl_translation

This package provides message extraction and code generation from translated messages for the Intl package. It's a separate package so as to not require a dependency on analyzer for all users.

Extracting And Using Translated Messages

When your program contains messages that need translation, these must be extracted from the program source, sent to human translators, and the results need to be incorporated.

To extract messages, run the extract_to_arb.dart program.

  pub run intl_translation:extract_to_arb --output-dir=target/directory
      my_program.dart more_of_my_program.dart

This will produce a file intl_messages.arb with the messages from all of these programs. This is an ARB format file which can be used for input to translation tools like Localizely or (the deprecated) Google Translator Toolkit. The resulting translations can be used to generate a set of libraries using the generate_from_arb.dart program.

This expects to receive a series of files, one per locale.

pub run intl_translation:generate_from_arb --generated-file-prefix=<prefix>
    <my_dart_files> <translated_ARB_files>

This will generate Dart libraries, one per locale, which contain the translated versions. Your Dart libraries can import the primary file, named <prefix>messages_all.dart, and then call the initialization for a specific locale. Once that's done, any Intl.message calls made in the context of that locale will automatically print the translated version instead of the original.

import "my_prefix_messages_all.dart";
...
initializeMessages("dk").then(printSomeMessages);

Once the Future returned from the initialization call completes, the message data is available.

Libraries

extract_messages
This is for use in extracting messages from a Dart program using the Intl.message() mechanism and writing them to a file for translation. This provides only the stub of a mechanism, because it doesn't define how the file should be written. It provides an IntlMessage class that holds the extracted data and parseString and parseFile methods which can extract messages that conform to the expected pattern: (parameters) => Intl.message("Message $parameters", desc: ...); It uses the analyzer package to do the parsing, so may break if there are changes to the API that it provides. An example can be found in test/message_extraction/extract_to_json.dart [...]
generate_localized
This provides utilities for generating localized versions of messages. It does not stand alone, but expects to be given TranslatedMessage objects and generate code for a particular locale based on them. [...]