37 lines
1.4 KiB
Go
37 lines
1.4 KiB
Go
|
// Copyright (c) 2016 The btcsuite developers
|
||
|
|
// Use of this source code is governed by an ISC
|
||
|
|
// license that can be found in the LICENSE file.
|
||
|
|
|
||
|
|
package cfgutil
|
||
|
|
|
||
|
|
// ExplicitString is a string value implementing the flags.Marshaler and
|
||
|
|
// flags.Unmarshaler interfaces so it may be used as a config struct field. It
|
||
|
|
// records whether the value was explicitly set by the flags package. This is
|
||
|
|
// useful when behavior must be modified depending on whether a flag was set by
|
||
|
|
// the user or left as a default. Without recording this, it would be
|
||
|
|
// impossible to determine whether flag with a default value was unmodified or
|
||
|
|
// explicitly set to the default.
|
||
|
|
type ExplicitString struct {
|
||
|
|
Value string
|
||
|
|
explicitlySet bool
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewExplicitString creates a string flag with the provided default value.
|
||
|
|
func NewExplicitString(defaultValue string) *ExplicitString {
|
||
|
|
return &ExplicitString{Value: defaultValue, explicitlySet: false}
|
||
|
|
}
|
||
|
|
|
||
|
|
// ExplicitlySet returns whether the flag was explicitly set through the
|
||
|
|
// flags.Unmarshaler interface.
|
||
|
|
func (e *ExplicitString) ExplicitlySet() bool { return e.explicitlySet }
|
||
|
|
|
||
|
|
// MarshalFlag implements the flags.Marshaler interface.
|
||
|
|
func (e *ExplicitString) MarshalFlag() (string, error) { return e.Value, nil }
|
||
|
|
|
||
|
|
// UnmarshalFlag implements the flags.Unmarshaler interface.
|
||
|
|
func (e *ExplicitString) UnmarshalFlag(value string) error {
|
||
|
|
e.Value = value
|
||
|
|
e.explicitlySet = true
|
||
|
|
return nil
|
||
|
|
}
|