Golang FlagSet.VisitAll方法代碼示例

// Merge all of the flags from fsFrom into fsTo.
func AddPFlagSetToPFlagSet(fsFrom *pflag.FlagSet, fsTo *pflag.FlagSet) {
	fsFrom.VisitAll(func(f *pflag.Flag) {
		if fsTo.Lookup(f.Name) == nil {
			fsTo.AddFlag(f)
		}
	})
}

// findConfigurationConflicts iterates over the provided flags searching for
// duplicated configurations and unknown keys. It returns an error with all the conflicts if
// it finds any.
func findConfigurationConflicts(config map[string]interface{}, flags *pflag.FlagSet) error {
	// 1. Search keys from the file that we don't recognize as flags.
	unknownKeys := make(map[string]interface{})
	for key, value := range config {
		if flag := flags.Lookup(key); flag == nil {
			unknownKeys[key] = value
		}
	}

	// 2. Discard values that implement NamedOption.
	// Their configuration name differs from their flag name, like `labels` and `label`.
	if len(unknownKeys) > 0 {
		unknownNamedConflicts := func(f *pflag.Flag) {
			if namedOption, ok := f.Value.(opts.NamedOption); ok {
				if _, valid := unknownKeys[namedOption.Name()]; valid {
					delete(unknownKeys, namedOption.Name())
				}
			}
		}
		flags.VisitAll(unknownNamedConflicts)
	}

	if len(unknownKeys) > 0 {
		var unknown []string
		for key := range unknownKeys {
			unknown = append(unknown, key)
		}
		return fmt.Errorf("the following directives don't match any configuration option: %s", strings.Join(unknown, ", "))
	}

	var conflicts []string
	printConflict := func(name string, flagValue, fileValue interface{}) string {
		return fmt.Sprintf("%s: (from flag: %v, from file: %v)", name, flagValue, fileValue)
	}

	// 3. Search keys that are present as a flag and as a file option.
	duplicatedConflicts := func(f *pflag.Flag) {
		// search option name in the json configuration payload if the value is a named option
		if namedOption, ok := f.Value.(opts.NamedOption); ok {
			if optsValue, ok := config[namedOption.Name()]; ok {
				conflicts = append(conflicts, printConflict(namedOption.Name(), f.Value.String(), optsValue))
			}
		} else {
			// search flag name in the json configuration payload
			for _, name := range []string{f.Name, f.Shorthand} {
				if value, ok := config[name]; ok {
					conflicts = append(conflicts, printConflict(name, f.Value.String(), value))
					break
				}
			}
		}
	}

	flags.Visit(duplicatedConflicts)

	if len(conflicts) > 0 {
		return fmt.Errorf("the following directives are specified both as a flag and in the configuration file: %s", strings.Join(conflicts, ", "))
	}
	return nil
}

func genFlagResult(flags *pflag.FlagSet) []cmdOption {
	result := make([]cmdOption, 0)

	flags.VisitAll(func(flag *pflag.Flag) {
		// Todo, when we mark a shorthand is deprecated, but specify an empty message.
		// The flag.ShorthandDeprecated is empty as the shorthand is deprecated.
		// Using len(flag.ShorthandDeprecated) > 0 can't handle this, others are ok.
		if !(len(flag.ShorthandDeprecated) > 0) && len(flag.Shorthand) > 0 {
			opt := cmdOption{
				flag.Name,
				flag.Shorthand,
				flag.DefValue,
				forceMultiLine(flag.Usage),
			}
			result = append(result, opt)
		} else {
			opt := cmdOption{
				Name:         flag.Name,
				DefaultValue: forceMultiLine(flag.DefValue),
				Usage:        forceMultiLine(flag.Usage),
			}
			result = append(result, opt)
		}
	})

	return result
}

func deploymentDefaults(fs *pflag.FlagSet, f *fg.Flags, args []string) {
	// Merge Options
	fs.VisitAll(func(flag *pflag.Flag) {
		if !flag.Changed {
			value, ok := f.Options.Get(flag.Name)
			if ok {
				svalue := fmt.Sprintf("%v", value)
				err := fs.Set(flag.Name, svalue)
				if err != nil {
					Exitf("Error in option '%s': %#v\n", flag.Name, err)
				}
			}
		}
	})

	if f.Local {
		f.StopDelay = 5 * time.Second
		f.DestroyDelay = 3 * time.Second
		f.SliceDelay = 5 * time.Second
	}

	if f.JobPath == "" && len(args) >= 1 {
		f.JobPath = args[0]
	}
	if f.ClusterPath == "" && len(args) >= 2 {
		f.ClusterPath = args[1]
	}
}

func manPrintFlags(out *bytes.Buffer, flags *pflag.FlagSet) {
	flags.VisitAll(func(flag *pflag.Flag) {
		if len(flag.Deprecated) > 0 {
			return
		}
		format := ""
		if len(flag.Shorthand) > 0 {
			format = "**-%s**, **--%s**"
		} else {
			format = "%s**--%s**"
		}
		if len(flag.NoOptDefVal) > 0 {
			format = format + "["
		}
		if flag.Value.Type() == "string" {
			// put quotes on the value
			format = format + "=%q"
		} else {
			format = format + "=%s"
		}
		if len(flag.NoOptDefVal) > 0 {
			format = format + "]"
		}
		format = format + "\n\t%s\n\n"
		fmt.Fprintf(out, format, flag.Shorthand, flag.Name, flag.DefValue, flag.Usage)
	})
}

func rktFlagUsages(flagSet *pflag.FlagSet) string {
	x := new(bytes.Buffer)

	flagSet.VisitAll(func(flag *pflag.Flag) {
		if len(flag.Deprecated) > 0 || flag.Hidden {
			return
		}
		format := ""
		if len(flag.Shorthand) > 0 && len(flag.ShorthandDeprecated) == 0 {
			format = "  -%s, --%s"
		} else {
			format = "   %s   --%s"
		}
		if len(flag.NoOptDefVal) > 0 {
			format = format + "["
		}
		if flag.Value.Type() == "string" {
			// put quotes on the value
			format = format + "=%q"
		} else {
			format = format + "=%s"
		}
		if len(flag.NoOptDefVal) > 0 {
			format = format + "]"
		}
		format = format + "\t%s\n"
		shorthand := flag.Shorthand
		fmt.Fprintf(x, format, shorthand, flag.Name, flag.DefValue, flag.Usage)
	})

	return x.String()
}

func printFlags(out *bytes.Buffer, flags *pflag.FlagSet) {
	flags.VisitAll(func(flag *pflag.Flag) {
		if flag.Hidden {
			return
		}
		format := "**--%s**=%s\n\t%s\n\n"
		if flag.Value.Type() == "string" {
			// put quotes on the value
			format = "**--%s**=%q\n\t%s\n\n"
		}

		defValue := flag.DefValue
		if flag.Value.Type() == "duration" {
			defValue = "0"
		}

		if len(flag.Annotations["manpage-def-value"]) > 0 {
			defValue = flag.Annotations["manpage-def-value"][0]
		}

		// Todo, when we mark a shorthand is deprecated, but specify an empty message.
		// The flag.ShorthandDeprecated is empty as the shorthand is deprecated.
		// Using len(flag.ShorthandDeprecated) > 0 can't handle this, others are ok.
		if !(len(flag.ShorthandDeprecated) > 0) && len(flag.Shorthand) > 0 {
			format = "**-%s**, " + format
			fmt.Fprintf(out, format, flag.Shorthand, flag.Name, defValue, flag.Usage)
		} else {
			fmt.Fprintf(out, format, flag.Name, defValue, flag.Usage)
		}
	})
}

func getFlags(flagset *pflag.FlagSet) (flags []*pflag.Flag) {
	flags = make([]*pflag.Flag, 0)
	flagset.VisitAll(func(f *pflag.Flag) {
		flags = append(flags, f)
	})
	return
}

func (v *Viper) BindPFlags(flags *pflag.FlagSet) (err error) {
	flags.VisitAll(func(flag *pflag.Flag) {
		if err = v.BindPFlag(flag.Name, flag); err != nil {
			return
		}
	})
	return nil
}

// getConflictFreeConfiguration loads the configuration from a JSON file.
// It compares that configuration with the one provided by the flags,
// and returns an error if there are conflicts.
func getConflictFreeConfiguration(configFile string, flags *pflag.FlagSet) (*Config, error) {
	b, err := ioutil.ReadFile(configFile)
	if err != nil {
		return nil, err
	}

	var config Config
	var reader io.Reader
	if flags != nil {
		var jsonConfig map[string]interface{}
		reader = bytes.NewReader(b)
		if err := json.NewDecoder(reader).Decode(&jsonConfig); err != nil {
			return nil, err
		}

		configSet := configValuesSet(jsonConfig)

		if err := findConfigurationConflicts(configSet, flags); err != nil {
			return nil, err
		}

		// Override flag values to make sure the values set in the config file with nullable values, like `false`,
		// are not overridden by default truthy values from the flags that were not explicitly set.
		// See https://github.com/docker/docker/issues/20289 for an example.
		//
		// TODO: Rewrite configuration logic to avoid same issue with other nullable values, like numbers.
		namedOptions := make(map[string]interface{})
		for key, value := range configSet {
			f := flags.Lookup(key)
			if f == nil { // ignore named flags that don't match
				namedOptions[key] = value
				continue
			}

			if _, ok := f.Value.(boolValue); ok {
				f.Value.Set(fmt.Sprintf("%v", value))
			}
		}
		if len(namedOptions) > 0 {
			// set also default for mergeVal flags that are boolValue at the same time.
			flags.VisitAll(func(f *pflag.Flag) {
				if opt, named := f.Value.(opts.NamedOption); named {
					v, set := namedOptions[opt.Name()]
					_, boolean := f.Value.(boolValue)
					if set && boolean {
						f.Value.Set(fmt.Sprintf("%v", v))
					}
				}
			})
		}

		config.valuesSet = configSet
	}

	reader = bytes.NewReader(b)
	err = json.NewDecoder(reader).Decode(&config)
	return &config, err
}

func sansAdditionalFlags(flags *flag.FlagSet) *flag.FlagSet {
	fs := &flag.FlagSet{}
	flags.VisitAll(func(f *flag.Flag) {
		if c.AdditionalFlags.Lookup(f.Name) == nil {
			fs.AddFlag(f)
		}
	})
	return fs
}

func (c *CLI) sansDriverFlags(flags *flag.FlagSet) *flag.FlagSet {
	fs := &flag.FlagSet{}
	flags.VisitAll(func(f *flag.Flag) {
		if c.driverFlags().Lookup(f.Name) == nil {
			fs.AddFlag(f)
		}
	})
	return fs
}

func flagsNotIntersected(l *flag.FlagSet, r *flag.FlagSet) *flag.FlagSet {
	f := flag.NewFlagSet("notIntersected", flag.ContinueOnError)
	l.VisitAll(func(flag *flag.Flag) {
		if r.Lookup(flag.Name) == nil {
			f.AddFlag(flag)
		}
	})
	return f
}

// Test if the named flag is a boolean flag.
func isBooleanShortFlag(name string, f *flag.FlagSet) bool {
	result := false
	f.VisitAll(func(f *flag.Flag) {
		if f.Shorthand == name && f.Value.Type() == "bool" {
			result = true
		}
	})
	return result
}

func visibleFlags(l *flag.FlagSet) *flag.FlagSet {
	hidden := "help"
	f := flag.NewFlagSet("visible", flag.ContinueOnError)
	l.VisitAll(func(flag *flag.Flag) {
		if flag.Name != hidden {
			f.AddFlag(flag)
		}
	})
	return f
}