namespace_example_test.go

package verbs_test

import (
	"fmt"
	"os"

	"github.com/revl/verbs"
)

var cloudCLI = &verbs.CLI{
	ProgramName:      "cloud",
	Summary:          "Manage cloud resources",
	Version:          "1.0.0",
	OptionResolution: verbs.Global,
	Options: []*verbs.Option{{
		Name:        "v|verbose",
		Description: "Show more output",
		Tag:         "verbose",
	}},
	Namespaces: []*verbs.Namespace{{
		Name:    "vm",
		Summary: "Virtual machine operations",
		Options: []*verbs.Option{{
			Name:        "r|region",
			Param:       "REGION",
			Description: "Target region",
			Tag:         "region",
		}},
		Commands: []*verbs.Command{{
			Name:        "create",
			Summary:     "Provision a VM",
			Description: "Creates a VM with an image and size.",
			Options: []*verbs.Option{{
				Name:        "i|image",
				Param:       "IMAGE",
				Description: "Image ID",
				Tag:         "image",
			}},
			Args: []*verbs.Arg{{Name: "NAME", Tag: "name"}},
			Tag:  "vm-create",
		}},
	}},
	HelpTopics: []*verbs.HelpTopic{{
		Keyword: "examples",
		Summary: "Try these common tasks",
		Text:    "cloud vm create demo --image=ubuntu --region=us-east-1",
	}},
}

// This example demonstrates how to use namespaces to organize commands and
// options hierarchically. Nested commands must be prefixed with the namespace
// name on the command line in order to be resolved.
func ExampleNamespace() {
	result := verbs.NewParser(cloudCLI).Parse(os.Args)

	fmt.Println("Selected command:", result.Command.Tag)
	for _, arg := range result.OptsAndArgs {
		fmt.Printf("%v: %q\n", arg.Tag, arg.Value)
	}
}