clap-i18n-richformatter

i18n support for clap::error::RichFormatter!

Usage

Add clap-i18n-richformatter to Cargo.toml:

clap-i18n-richformatter = "0.1.0"

Initialise clap-i18n-richformatter as such:

use clap::Parser;
use clap_i18n_richformatter::{ClapI18nRichFormatter, init_clap_rich_formatter_localizer};

#[derive(Debug, Parser)]
struct ExampleArg {
    #[arg(long, short)]
    a: bool,
    #[arg(long, short, requires = "a")]
    b: bool,
}

fn main() {
    init_clap_rich_formatter_localizer();
    let args = ExampleArg::try_parse()
        .map_err(|e| {
            let e = e.apply::<ClapI18nRichFormatter>();
            e.exit();
        })
        .unwrap();

    dbg!(args);
}

Running LANG=zh_CN.UTF-8 cargo run -- -b and LANG=C cargo run -- -b will now show localised (and non-localised below) error output for Clap:

错误: 未提供下列必要参数:
  --a

用法: arg_requires --a --b

如需了解更多信息，请输入 --help。

error: the following required arguments were not provided:
  --a

Usage: arg_requires --a --b

For more information, try '--help'.

Contribution

Your contribution are welcome via Pull Requests:

• Code improvement (of course).
• Localisation to other languages, see i18n/ for l10n metadata (in Fluent).

Inspiration

From https://github.com/clap-rs/clap/issues/380#issuecomment-1254059266:

In discussing this with someone on reddit, I think users can get something working, even if it isn't streamlined yet

• Replace Commands: header with a localized value via Command::subcommand_help_heading
• Replace value name with a localized value via Command::subcommand_value_name
• Replace Arguments and Options: headers with localized values via Command::next_help_heading and/or Arg::help_heading
• Disable the built-in flags (Command::disable_help_flag(false) and Command::disable_version_flag(false)) and provide your own versions with localized Arg::help
• If the help template has any hard coded strings, replace them with a localized version via Command::help_template
• Fork clap::error::RichFormatter, replacing any hard coded strings with localized values. Use Error::apply to swap the formatter (e.g. use Parser::try_parse to get the error, call apply, and then err.exit())

clap-i18n-richformatter follows the last suggesion from @epage to implement i18n support for Clap errors, since the error messages are quite finite and predictable.

Fork clap::error::RichFormatter, replacing any hard coded strings with localized values. Use Error::apply to swap the formatter (e.g. use Parser::try_parse to get the error, call apply, and then err.exit())