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- package altsrc
-
- import (
- "fmt"
- "strconv"
- "strings"
- "syscall"
-
- "gopkg.in/urfave/cli.v1"
- )
-
- // 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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