build_cli 0.2.0

Parse command line arguments directly into an annotation class using the power of build_runner and source_gen.

Parse command line arguments directly into an annotation class using the Dart Build System.

Example

Annotate a class with @CliOptions() from package:build_cli_annotations.

import 'package:build_cli_annotations/build_cli_annotations.dart';

part 'example.g.dart';

@CliOptions()
class Options {
  @CliOption(abbr: 'n', help: 'Required. The name to use in the greeting.')
  final String name;

  final bool nameWasParsed;

  bool yell;

  @CliOption(defaultsTo: Language.en, abbr: 'l')
  Language displayLanguage;

  @CliOption(negatable: false, help: 'Prints usage information.')
  bool help;

  Options(this.name, {this.nameWasParsed});
}

enum Language { en, es }

Configure and run the Dart Build System and a set of helpers is created to parse the corresponding command line arguments and populate your class.

void main(List<String> args) {
  var options = parseOptions(args);
  if (!options.nameWasParsed) {
    throw new ArgumentError('You must set `name`.');
  }
  print(options.name);
}

Setup

Add three packages to pubspec.yaml:

dependencies:
  build_cli_annotations: ^0.1.0

dev_dependencies:
  build_cli: ^0.2.0
  build_runner: '>=0.7.10 <0.9.0'

• build_cli_annotations is a separate package containing the annotations you add to classes and members to tell build_cli what to do.
  • If the code you're annotating is in a published directory – lib, bin – put it in the dependencies section.
• build_cli contains the logic to generate the code.
  • It should almost always be put in dev_dependencies.
• build_runner contains the logic to run a build and generate code.
  • It should almost always be put in dev_dependencies.

Details

Uses package:args under the covers.

More examples:

• The package contains a fully documented end-to-end example.
• The test directory contains implementations that exercise most of the features of this package.
• Also look at the package:peanut source code. The options files in the src directory as the interesting files.