k3s/vendor/github.com/urfave/cli/v2/flag_generic.go

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2020-03-26 21:07:15 +00:00
package cli
import (
"flag"
"fmt"
)
// Generic is a generic parseable type identified by a specific flag
type Generic interface {
Set(value string) error
String() string
}
// GenericFlag is a flag with type Generic
type GenericFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
FilePath string
Required bool
Hidden bool
TakesFile bool
Value Generic
DefaultText string
HasBeenSet bool
}
// IsSet returns whether or not the flag has been set through env or file
func (f *GenericFlag) IsSet() bool {
return f.HasBeenSet
}
// String returns a readable representation of this value
// (for usage defaults)
func (f *GenericFlag) String() string {
return FlagStringer(f)
}
// Names returns the names of the flag
func (f *GenericFlag) Names() []string {
return flagNames(f.Name, f.Aliases)
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}
// IsRequired returns whether or not the flag is required
func (f *GenericFlag) IsRequired() bool {
return f.Required
}
// TakesValue returns true of the flag takes a value, otherwise false
func (f *GenericFlag) TakesValue() bool {
return true
}
// GetUsage returns the usage string for the flag
func (f *GenericFlag) GetUsage() string {
return f.Usage
}
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *GenericFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
}
return ""
}
// Apply takes the flagset and calls Set on the generic flag with the value
// provided by the user for parsing by the flag
func (f GenericFlag) Apply(set *flag.FlagSet) error {
if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {
if val != "" {
if err := f.Value.Set(val); err != nil {
return fmt.Errorf("could not parse %q as value for flag %s: %s", val, f.Name, err)
}
f.HasBeenSet = true
}
}
for _, name := range f.Names() {
set.Var(f.Value, name, f.Usage)
}
return nil
}
// Generic looks up the value of a local GenericFlag, returns
// nil if not found
func (c *Context) Generic(name string) interface{} {
if fs := lookupFlagSet(name, c); fs != nil {
return lookupGeneric(name, fs)
}
return nil
}
func lookupGeneric(name string, set *flag.FlagSet) interface{} {
f := set.Lookup(name)
if f != nil {
parsed, err := f.Value, error(nil)
if err != nil {
return nil
}
return parsed
}
return nil
}