Call FlagStringer in String() method of slice flags

The default help template relies on the String() method of Flag
to render the flag. For most flag types, String() indirects through
FlagStringer, so that is the best place to customize flag rendering.

FlagStringer was not called for slice flags because their help output
differs from other flags in two ways: there can be multiple default
values, and the flag name is shown two times to indicate that the flag
can be specified multiple times.

To make multiple values work in the FlagStringer, I simply changed
GetValue() to return all values.

Showing the flag more than once is achieved through a new interface,
DocGenerationSliceFlag, which the FlagStringer uses to decide whether
the flag is a slice flag type.
This commit is contained in:
Felix Lange 2022-09-30 15:01:22 +02:00
parent 6491ddec12
commit 72cbb3db6a
8 changed files with 97 additions and 119 deletions

29
flag.go
View File

@ -129,6 +129,14 @@ type DocGenerationFlag interface {
GetEnvVars() []string
}
// DocGenerationSliceFlag extends DocGenerationFlag for slice-based flags.
type DocGenerationSliceFlag interface {
DocGenerationFlag
// IsSliceFlag returns true for flags that can be given multiple times.
IsSliceFlag() bool
}
// VisibleFlag is an interface that allows to check if a flag is visible
type VisibleFlag interface {
Flag
@ -325,24 +333,13 @@ func stringifyFlag(f Flag) string {
usageWithDefault := strings.TrimSpace(usage + defaultValueString)
return withEnvHint(df.GetEnvVars(),
fmt.Sprintf("%s\t%s", prefixedNames(df.Names(), placeholder), usageWithDefault))
}
func stringifySliceFlag(usage string, names, defaultVals []string) string {
placeholder, usage := unquoteUsage(usage)
if placeholder == "" {
placeholder = defaultPlaceholder
pn := prefixedNames(df.Names(), placeholder)
sliceFlag, ok := f.(DocGenerationSliceFlag)
if ok && sliceFlag.IsSliceFlag() {
pn = pn + " [ " + pn + " ]"
}
defaultVal := ""
if len(defaultVals) > 0 {
defaultVal = fmt.Sprintf(formatDefault("%s"), strings.Join(defaultVals, ", "))
}
usageWithDefault := strings.TrimSpace(fmt.Sprintf("%s%s", usage, defaultVal))
pn := prefixedNames(names, placeholder)
return fmt.Sprintf("%s [ %s ]\t%s", pn, pn, usageWithDefault)
return withEnvHint(df.GetEnvVars(), fmt.Sprintf("%s\t%s", pn, usageWithDefault))
}
func hasFlag(flags []Flag, fl Flag) bool {

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@ -83,7 +83,7 @@ func (f *Float64Slice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *Float64SliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true if the flag takes a value, otherwise false
@ -104,10 +104,13 @@ func (f *Float64SliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *Float64SliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strings.TrimRight(strings.TrimRight(fmt.Sprintf("%f", i), "0"), "."))
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -123,6 +126,11 @@ func (f *Float64SliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *Float64SliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *Float64SliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -169,18 +177,6 @@ func (f *Float64SliceFlag) Get(ctx *Context) []float64 {
return ctx.Float64Slice(f.Name)
}
func (f *Float64SliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strings.TrimRight(strings.TrimRight(fmt.Sprintf("%f", i), "0"), "."))
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// RunAction executes flag action if set
func (f *Float64SliceFlag) RunAction(c *Context) error {
if f.Action != nil {

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@ -84,7 +84,7 @@ func (i *Int64Slice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *Int64SliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true of the flag takes a value, otherwise false
@ -105,10 +105,13 @@ func (f *Int64SliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *Int64SliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatInt(i, 10))
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -124,6 +127,11 @@ func (f *Int64SliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *Int64SliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *Int64SliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -168,17 +176,6 @@ func (f *Int64SliceFlag) Get(ctx *Context) []int64 {
return ctx.Int64Slice(f.Name)
}
func (f *Int64SliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatInt(i, 10))
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// RunAction executes flag action if set
func (f *Int64SliceFlag) RunAction(c *Context) error {
if f.Action != nil {

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@ -95,7 +95,7 @@ func (i *IntSlice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *IntSliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true of the flag takes a value, otherwise false
@ -116,10 +116,13 @@ func (f *IntSliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *IntSliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.Itoa(i))
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -135,6 +138,11 @@ func (f *IntSliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *IntSliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *IntSliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -188,17 +196,6 @@ func (f *IntSliceFlag) RunAction(c *Context) error {
return nil
}
func (f *IntSliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.Itoa(i))
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// IntSlice looks up the value of a local IntSliceFlag, returns
// nil if not found
func (cCtx *Context) IntSlice(name string) []int {

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@ -74,7 +74,7 @@ func (s *StringSlice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *StringSliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true of the flag takes a value, otherwise false
@ -95,10 +95,15 @@ func (f *StringSliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *StringSliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, s := range f.Value.Value() {
if len(s) > 0 {
defaultVals = append(defaultVals, strconv.Quote(s))
}
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -114,6 +119,11 @@ func (f *StringSliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *StringSliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *StringSliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -158,19 +168,6 @@ func (f *StringSliceFlag) Get(ctx *Context) []string {
return ctx.StringSlice(f.Name)
}
func (f *StringSliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, s := range f.Value.Value() {
if len(s) > 0 {
defaultVals = append(defaultVals, strconv.Quote(s))
}
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// RunAction executes flag action if set
func (f *StringSliceFlag) RunAction(c *Context) error {
if f.Action != nil {

View File

@ -307,12 +307,12 @@ func TestFlagStringifying(t *testing.T) {
{
name: "float64-slice-flag",
fl: &Float64SliceFlag{Name: "pizzas"},
expected: "--pizzas value\t",
expected: "--pizzas value [ --pizzas value ]\t",
},
{
name: "float64-slice-flag-with-default-text",
fl: &Float64SliceFlag{Name: "pepperonis", DefaultText: "shaved"},
expected: "--pepperonis value\t(default: shaved)",
expected: "--pepperonis value [ --pepperonis value ]\t(default: shaved)",
},
{
name: "generic-flag",
@ -337,7 +337,7 @@ func TestFlagStringifying(t *testing.T) {
{
name: "int-slice-flag",
fl: &IntSliceFlag{Name: "pencils"},
expected: "--pencils value\t",
expected: "--pencils value [ --pencils value ]\t",
},
{
name: "int-slice-flag-with-default-text",
@ -347,7 +347,7 @@ func TestFlagStringifying(t *testing.T) {
{
name: "uint-slice-flag",
fl: &UintSliceFlag{Name: "pencils"},
expected: "--pencils value\t",
expected: "--pencils value [ --pencils value ]\t",
},
{
name: "uint-slice-flag-with-default-text",
@ -367,22 +367,22 @@ func TestFlagStringifying(t *testing.T) {
{
name: "int64-slice-flag",
fl: &Int64SliceFlag{Name: "drawers"},
expected: "--drawers value\t",
expected: "--drawers value [ --drawers value ]\t",
},
{
name: "int64-slice-flag-with-default-text",
fl: &Int64SliceFlag{Name: "handles", DefaultText: "-2"},
expected: "--handles value\t(default: -2)",
expected: "--handles value [ --handles value ]\t(default: -2)",
},
{
name: "uint64-slice-flag",
fl: &Uint64SliceFlag{Name: "drawers"},
expected: "--drawers value\t",
expected: "--drawers value [ --drawers value ]\t",
},
{
name: "uint64-slice-flag-with-default-text",
fl: &Uint64SliceFlag{Name: "handles", DefaultText: "-2"},
expected: "--handles value\t(default: -2)",
expected: "--handles value [ --handles value ]\t(default: -2)",
},
{
name: "path-flag",
@ -407,12 +407,12 @@ func TestFlagStringifying(t *testing.T) {
{
name: "string-slice-flag",
fl: &StringSliceFlag{Name: "meow-sounds"},
expected: "--meow-sounds value\t",
expected: "--meow-sounds value [ --meow-sounds value ]\t",
},
{
name: "string-slice-flag-with-default-text",
fl: &StringSliceFlag{Name: "moo-sounds", DefaultText: "awoo"},
expected: "--moo-sounds value\t(default: awoo)",
expected: "--moo-sounds value [ --moo-sounds value ]\t(default: awoo)",
},
{
name: "timestamp-flag",

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@ -88,7 +88,7 @@ func (i *Uint64Slice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *Uint64SliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true of the flag takes a value, otherwise false
@ -109,10 +109,13 @@ func (f *Uint64SliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *Uint64SliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatUint(i, 10))
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -128,6 +131,11 @@ func (f *Uint64SliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *Uint64SliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *Uint64SliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -172,17 +180,6 @@ func (f *Uint64SliceFlag) Get(ctx *Context) []uint64 {
return ctx.Uint64Slice(f.Name)
}
func (f *Uint64SliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatUint(i, 10))
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// Uint64Slice looks up the value of a local Uint64SliceFlag, returns
// nil if not found
func (cCtx *Context) Uint64Slice(name string) []uint64 {

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@ -99,7 +99,7 @@ func (i *UintSlice) Get() interface{} {
// String returns a readable representation of this value
// (for usage defaults)
func (f *UintSliceFlag) String() string {
return withEnvHint(f.GetEnvVars(), f.stringify())
return FlagStringer(f)
}
// TakesValue returns true of the flag takes a value, otherwise false
@ -120,10 +120,13 @@ func (f *UintSliceFlag) GetCategory() string {
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *UintSliceFlag) GetValue() string {
if f.Value != nil {
return f.Value.String()
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatUint(uint64(i), 10))
}
}
return ""
return strings.Join(defaultVals, ", ")
}
// GetDefaultText returns the default text for this flag
@ -139,6 +142,11 @@ func (f *UintSliceFlag) GetEnvVars() []string {
return f.EnvVars
}
// IsSliceFlag implements DocGenerationSliceFlag.
func (f *UintSliceFlag) IsSliceFlag() bool {
return true
}
// Apply populates the flag given the flag set and environment
func (f *UintSliceFlag) Apply(set *flag.FlagSet) error {
// apply any default
@ -183,17 +191,6 @@ func (f *UintSliceFlag) Get(ctx *Context) []uint {
return ctx.UintSlice(f.Name)
}
func (f *UintSliceFlag) stringify() string {
var defaultVals []string
if f.Value != nil && len(f.Value.Value()) > 0 {
for _, i := range f.Value.Value() {
defaultVals = append(defaultVals, strconv.FormatUint(uint64(i), 10))
}
}
return stringifySliceFlag(f.Usage, f.Names(), defaultVals)
}
// UintSlice looks up the value of a local UintSliceFlag, returns
// nil if not found
func (cCtx *Context) UintSlice(name string) []uint {