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package altsrc
import (
"fmt"
"strconv"
"strings"
"syscall"
"github.com/urfave/cli"
)
// FlagInputSourceExtension is an extension interface of cli.Flag that
// allows a value to be set on the existing parsed flags.
type FlagInputSourceExtension interface {
cli.Flag
ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error
}
// ApplyInputSourceValues iterates over all provided flags and
// executes ApplyInputSourceValue on flags implementing the
// FlagInputSourceExtension interface to initialize these flags
// to an alternate input source.
func ApplyInputSourceValues(context *cli.Context, inputSourceContext InputSourceContext, flags []cli.Flag) error {
for _, f := range flags {
inputSourceExtendedFlag, isType := f.(FlagInputSourceExtension)
if isType {
err := inputSourceExtendedFlag.ApplyInputSourceValue(context, inputSourceContext)
if err != nil {
return err
}
}
}
return nil
}
// InitInputSource is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
// input source based on the func provided. If there is no error it will then apply the new input source to any flags
// that are supported by the input source
func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceContext, error)) cli.BeforeFunc {
return func(context *cli.Context) error {
inputSource, err := createInputSource()
if err != nil {
return fmt.Errorf("Unable to create input source: inner error: \n'%v'", err.Error())
}
return ApplyInputSourceValues(context, inputSource, flags)
}
}
// InitInputSourceWithContext is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
// input source based on the func provided with potentially using existing cli.Context values to initialize itself. If there is
// no error it will then apply the new input source to any flags that are supported by the input source
func InitInputSourceWithContext(flags []cli.Flag, createInputSource func(context *cli.Context) (InputSourceContext, error)) cli.BeforeFunc {
return func(context *cli.Context) error {
inputSource, err := createInputSource(context)
if err != nil {
return fmt.Errorf("Unable to create input source with context: inner error: \n'%v'", err.Error())
}
return ApplyInputSourceValues(context, inputSource, flags)
}
}
// ApplyInputSourceValue applies a generic value to the flagSet if required
func (f *GenericFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
value, err := isc.Generic(f.GenericFlag.Name)
if err != nil {
return err
}
if value != nil {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, value.String())
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a StringSlice value to the flagSet if required
func (f *StringSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
value, err := isc.StringSlice(f.StringSliceFlag.Name)
if err != nil {
return err
}
if value != nil {
var sliceValue cli.StringSlice = value
eachName(f.Name, func(name string) {
underlyingFlag := f.set.Lookup(f.Name)
if underlyingFlag != nil {
underlyingFlag.Value = &sliceValue
}
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a IntSlice value if required
func (f *IntSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
value, err := isc.IntSlice(f.IntSliceFlag.Name)
if err != nil {
return err
}
if value != nil {
var sliceValue cli.IntSlice = value
eachName(f.Name, func(name string) {
underlyingFlag := f.set.Lookup(f.Name)
if underlyingFlag != nil {
underlyingFlag.Value = &sliceValue
}
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a Bool value to the flagSet if required
func (f *BoolFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
value, err := isc.Bool(f.BoolFlag.Name)
if err != nil {
return err
}
if value {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, strconv.FormatBool(value))
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a BoolT value to the flagSet if required
func (f *BoolTFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
value, err := isc.BoolT(f.BoolTFlag.Name)
if err != nil {
return err
}
if !value {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, strconv.FormatBool(value))
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a String value to the flagSet if required
func (f *StringFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
value, err := isc.String(f.StringFlag.Name)
if err != nil {
return err
}
if value != "" {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, value)
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a int value to the flagSet if required
func (f *IntFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
value, err := isc.Int(f.IntFlag.Name)
if err != nil {
return err
}
if value > 0 {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, strconv.FormatInt(int64(value), 10))
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a Duration value to the flagSet if required
func (f *DurationFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
value, err := isc.Duration(f.DurationFlag.Name)
if err != nil {
return err
}
if value > 0 {
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, value.String())
})
}
}
}
return nil
}
// ApplyInputSourceValue applies a Float64 value to the flagSet if required
func (f *Float64Flag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
if f.set != nil {
if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
value, err := isc.Float64(f.Float64Flag.Name)
if err != nil {
return err
}
if value > 0 {
floatStr := float64ToString(value)
eachName(f.Name, func(name string) {
_ = f.set.Set(f.Name, floatStr)
})
}
}
}
return nil
}
func isEnvVarSet(envVars string) bool {
for _, envVar := range strings.Split(envVars, ",") {
envVar = strings.TrimSpace(envVar)
if _, ok := syscall.Getenv(envVar); ok {
// TODO: Can't use this for bools as
// set means that it was true or false based on
// Bool flag type, should work for other types
return true
}
}
return false
}
func float64ToString(f float64) string {
return fmt.Sprintf("%v", f)
}
func eachName(longName string, fn func(string)) {
parts := strings.Split(longName, ",")
for _, name := range parts {
name = strings.Trim(name, " ")
fn(name)
}
}
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