Text Help Generators

The Text help generator, also referred to as the CLI help generator, is the default help generator built into the core Airline library. It provides a full range of help generator implementations that can be used to generate help for CLIs, command groups and commands.

Available Implementations

The following implementations are available:

CliGlobalUsageGenerator - Full blown CLI help
CliGlobalUsageSummaryGenerator - Quick summary help for CLIs
CliCommandGroupUsageGenerator - Help for command groups
CliCommandUsageGenerator - Help for individual commands

Example Usage

Global Help

Using CliGlobalUsageGenerator:

   Cli<ExampleRunnable> cli = new Cli<ExampleRunnable>(ShipItCli.class);
        
   GlobalUsageGenerator<ExampleRunnable> helpGenerator = new CliGlobalUsageGenerator<>();
   try {
       helpGenerator.usage(cli.getMetadata(), System.out);
   } catch (IOException e) {
       e.printStackTrace();
   }

Using CliGlobalUsageSummaryGenerator:

   Cli<ExampleRunnable> cli = new Cli<ExampleRunnable>(ShipItCli.class);
        
   GlobalUsageGenerator<ExampleRunnable> helpGenerator = new CliGlobalUsageSummaryGenerator<>();
   try {
       helpGenerator.usage(cli.getMetadata(), System.out);
   } catch (IOException e) {
       e.printStackTrace();
   }

Command Group Help

Using CliCommandGroupUsageGenerator:

   Cli<ExampleRunnable> cli = new Cli<ExampleRunnable>(GroupCli.class);
        
   CommandGroupUsageGenerator<ExampleRunnable> helpGenerator = new CliCommandGroupUsageGenerator<>();
   try {
       helpGenerator.usage(cli.getMetadata(), new CommandGroupMetadata[] { cli.getMetadata().getCommandGroups().get(0) }, System.out);
   } catch (IOException e) {
       e.printStackTrace();
   }

Command Help

Using CliCommandUsageGenerator:

SingleCommand<Price> command = new SingleCommand<Price>(Price.class);

CommandUsageGenerator generator = new CliCommandUsageGenerator();
try {
    generator.usage(null, null, "price", command.getCommandMetadata(), command.getParserConfiguration(), System.out);
} catch (IOException e) {
    e.printStackTrace();
}

### Customisation

The main point of customisation for text based help is the number of columns to output i.e. the max number of character per line. This defaults to 79 which results in maximum line lengths of 80 characters barring some exceptions.

If you prefer you can create instances of the help generators with a different number of columns e.g.

CommandUsageGenerator = new CliCommandUsageGenerator(120);

Improving this Documentation

This documentation is itself open source and lives in GitHub under the docs/ directory.

I am not a professional technical writer and as the developer of this software I can often make assumptions of knowledge that you as a user reading this may not have. Improvements to the documentation are always welcome, if you have suggestions for the documentation please submit pull requests to the main branch.