timestamp flag

timestamp.go

package cli

import (
	"flag"
	"fmt"
	"time"

	"github.com/golang/protobuf/ptypes"
	protoTimestamp "github.com/golang/protobuf/ptypes/timestamp"
)

// TimestampFlag is a flag with type time.Duration (see https://golang.org/pkg/time/#ParseDuration)
type TimestampFlag struct {
	Name        string
	Aliases     []string
	Usage       string
	EnvVars     []string
	FilePath    string
	Required    bool
	Hidden      bool
	Value       protoTimestamp.Timestamp
	DefaultText string
	HasBeenSet  bool
}

// IsSet returns whether or not the flag has been set through env or file
func (f *TimestampFlag) IsSet() bool {
	return f.HasBeenSet
}

// String returns a readable representation of this value
// (for usage defaults)
func (f *TimestampFlag) String() string {
	return FlagStringer(f)
}

// Names returns the names of the flag
func (f *TimestampFlag) Names() []string {
	return flagNames(f)
}

// IsRequired returns whether or not the flag is required
func (f *TimestampFlag) IsRequired() bool {
	return f.Required
}

// TakesValue returns true of the flag takes a value, otherwise false
func (f *TimestampFlag) TakesValue() bool {
	return true
}

// GetUsage returns the usage string for the flag
func (f *TimestampFlag) 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 *TimestampFlag) GetValue() string {
	return ""//f.Value.String()
}

// Apply populates the flag given the flag set and environment
func (f *TimestampFlag) Apply(set *flag.FlagSet) error {
	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {
		if val != "" {

			layout := "2006-01-02T15:04:05"
			parsedTime, err := time.Parse(layout, val)
			if err != nil {
				return fmt.Errorf("could not parse %q as timestamp value for flag %s: %s", val, f.Name, err)
			}

			timestamp, err := ptypes.TimestampProto(parsedTime)
			if err != nil {
				return fmt.Errorf("could not parse %q as a proto timestamp value for flag %s: %s", val, f.Name, err)
			}

			f.Value = *timestamp
			f.HasBeenSet = true
		}
	}

	for _, name := range f.Names() {
		set.Var(f.Value, name, f.Usage)
	}
	return nil
}