command flags usage

[emicklei]

I found unexpected behavior when working with command related flags. Perhaps I misunderstand it. I wrote a minimal example.

go run main.go test -s flag -g

and read

2018/02/21 14:29:25 s= false
2018/02/21 14:29:25 g= true

Why is s not set ? or what should the command line be ?

package main

import (
	"log"
	"os"

	"github.com/urfave/cli"
)

func main() {
	app := cli.NewApp()
	app.Commands = []cli.Command{
		{
			Name: "test",
			Flags: []cli.Flag{
				cli.BoolFlag{
					Name: "set, s",
				},
			},
			Subcommands: []cli.Command{
				{
					Name:   "flag",
					Action: cmdTestFlag,
					Flags: []cli.Flag{
						cli.BoolFlag{
							Name: "get, g",
						},
					},
				},
			},
		},
	}
	if err := app.Run(os.Args); err != nil {
		log.Fatalln(err)
	}
}

func cmdTestFlag(c *cli.Context) error {
	log.Println("s=", c.Bool("s"))
	log.Println("g=", c.Bool("g"))
	return nil
}

[daniel-nichter]

Had similar issue and c.GlobalBool worked. I can't find mention in the docs but I think each Command has its own context, so s doesn't exist in the (sub)command context, and given,

Bool looks up the value of a local BoolFlag, returns false if not found

accessing the bool var returns false not because it's actually false but because it doesn't exist in the context.

[coilysiren]

I'm marking this as a bug since it's a bug from a user PoV! From the PoV of the CLI, it'd be nice if all flags were functionally "global" 👍 I would be very interested in reviewing any PRs for this! 🙏

[coilysiren]

I've been thinking about this more, and I think we want to achieve this

it'd be nice if all flags were functionally "global"

with a config option, and then make that option the default value in v3. I'm tracking V3 here #833

[coilysiren]

I'm going to bucket this as a part of potential V3 work, and close this specific issue - but I fully intend on following up on this problem!