Cli: Enum Support

Created on 26 Feb 2017 · 11Comments · Source: urfave/cli

Option values often only support a limited set of valid values. It would be helpful to have CLI enforce valid options and auto generate help docs listing valid options.

arev2 kinfeature statuclaimed statustale

Source

coen-hyde

👍6

Most helpful comment

The following might be helpful:

type EnumValue struct {
    Enum     []string
    Default  string
    selected string
}

func (e *EnumValue) Set(value string) error {
    for _, enum := range e.Enum {
        if enum == value {
            e.selected = value
            return nil
        }
    }

    return fmt.Errorf("allowed values are %s", strings.Join(e.Enum, ", "))
}

func (e EnumValue) String() string {
    if e.selected == "" {
        return e.Default
    }
    return e.selected
}

Usage:

app.Flags = []cli.Flag{
    cli.GenericFlag{
        Name: "format, f",
        Value: &EnumValue{
            Enum:    []string{"json", "plist", "xml"},
            Default: "json",
        },
        Usage: "output in json, plist or xml format",
    },
}

alyyousuf7 on 26 Aug 2018

👍6

All 11 comments

:+1: this is possible via the GenericFlag, but I'll mark this as a possible enhancement.

Thanks!

jszwedko on 27 Feb 2017

BlueBeN82 on 19 Aug 2017

maheshvra on 19 Jan 2018

The following might be helpful:

type EnumValue struct {
    Enum     []string
    Default  string
    selected string
}

func (e *EnumValue) Set(value string) error {
    for _, enum := range e.Enum {
        if enum == value {
            e.selected = value
            return nil
        }
    }

    return fmt.Errorf("allowed values are %s", strings.Join(e.Enum, ", "))
}

func (e EnumValue) String() string {
    if e.selected == "" {
        return e.Default
    }
    return e.selected
}

Usage:

app.Flags = []cli.Flag{
    cli.GenericFlag{
        Name: "format, f",
        Value: &EnumValue{
            Enum:    []string{"json", "plist", "xml"},
            Default: "json",
        },
        Usage: "output in json, plist or xml format",
    },
}

alyyousuf7 on 26 Aug 2018

👍6

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