Extracting messages

Now, we have all the messages separated from the UI and we are ready for translation. We need to extract them from the source code into the external file with a special program called extract_to_arb.dart from the intl package, as shown in the following code:

pub run intl:extract_to_arb --output-dir=web web/registration_form.dart

The preceding program generates the intl_messages.arb file inside the specified web directory. This file contains all the messages in the ARB format. ARB is a localization resource format based on JSON. This format provides the following benefits:

• Simplicity: This format is simple and human-readable because it is based on JSON

• Extensibility: In this format, vocabulary can be added without affecting the existing tools and usage

• Direct usability: Applications can access the resource directly from this format without converting them to another form

You can find more about the ARB format in the specification available at https://code.google.com/p/arb...