File: helpValues.go

package info (click to toggle)
golang-github-integrii-flaggy 1.4.0-1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, sid
  • size: 292 kB
  • sloc: makefile: 3
file content (289 lines) | stat: -rw-r--r-- 8,018 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
package flaggy

import (
	"log"
	"reflect"
	"strings"
	"unicode/utf8"
)

// Help represents the values needed to render a Help page
type Help struct {
	Subcommands    []HelpSubcommand
	Positionals    []HelpPositional
	Flags          []HelpFlag
	UsageString    string
	CommandName    string
	PrependMessage string
	AppendMessage  string
	Message        string
	Description    string
}

// HelpSubcommand is used to template subcommand Help output
type HelpSubcommand struct {
	ShortName   string
	LongName    string
	Description string
	Position    int
	Spacer      string
}

// HelpPositional is used to template positional Help output
type HelpPositional struct {
	Name         string
	Description  string
	Required     bool
	Position     int
	DefaultValue string
	Spacer       string
}

// HelpFlag is used to template string flag Help output
type HelpFlag struct {
	ShortName    string
	LongName     string
	Description  string
	DefaultValue string
	Spacer       string
}

// ExtractValues extracts Help template values from a subcommand and its parent
// parser. The parser is required in order to detect default flag settings
// for help and version output.
func (h *Help) ExtractValues(p *Parser, message string) {

	// accept message string for output
	h.Message = message

	// extract Help values from the current subcommand in context
	// prependMessage string
	h.PrependMessage = p.subcommandContext.AdditionalHelpPrepend
	// appendMessage  string
	h.AppendMessage = p.subcommandContext.AdditionalHelpAppend
	// command name
	h.CommandName = p.subcommandContext.Name
	// description
	h.Description = p.subcommandContext.Description

	maxLength := getLongestNameLength(p.subcommandContext.Subcommands, 0)

	// subcommands    []HelpSubcommand
	for _, cmd := range p.subcommandContext.Subcommands {
		if cmd.Hidden {
			continue
		}
		newHelpSubcommand := HelpSubcommand{
			ShortName:   cmd.ShortName,
			LongName:    cmd.Name,
			Description: cmd.Description,
			Position:    cmd.Position,
			Spacer:      makeSpacer(cmd.Name, maxLength),
		}
		h.Subcommands = append(h.Subcommands, newHelpSubcommand)
	}

	maxLength = getLongestNameLength(p.subcommandContext.PositionalFlags, 0)

	// parse positional flags into help output structs
	for _, pos := range p.subcommandContext.PositionalFlags {
		if pos.Hidden {
			continue
		}
		newHelpPositional := HelpPositional{
			Name:         pos.Name,
			Position:     pos.Position,
			Description:  pos.Description,
			Required:     pos.Required,
			DefaultValue: pos.defaultValue,
			Spacer:       makeSpacer(pos.Name, maxLength),
		}
		h.Positionals = append(h.Positionals, newHelpPositional)
	}

	maxLength = len(versionFlagLongName)
	if len(helpFlagLongName) > maxLength {
		maxLength = len(helpFlagLongName)
	}
	maxLength = getLongestNameLength(p.subcommandContext.Flags, maxLength)
	maxLength = getLongestNameLength(p.Flags, maxLength)

	// if the built-in version flag is enabled, then add it as a help flag
	if p.ShowVersionWithVersionFlag {
		defaultVersionFlag := HelpFlag{
			ShortName:    "",
			LongName:     versionFlagLongName,
			Description:  "Displays the program version string.",
			DefaultValue: "",
			Spacer:       makeSpacer(versionFlagLongName, maxLength),
		}
		h.Flags = append(h.Flags, defaultVersionFlag)
	}

	// if the built-in help flag exists, then add it as a help flag
	if p.ShowHelpWithHFlag {
		defaultHelpFlag := HelpFlag{
			ShortName:    helpFlagShortName,
			LongName:     helpFlagLongName,
			Description:  "Displays help with available flag, subcommand, and positional value parameters.",
			DefaultValue: "",
			Spacer:       makeSpacer(helpFlagLongName, maxLength),
		}
		h.Flags = append(h.Flags, defaultHelpFlag)
	}

	// go through every flag in the subcommand and add it to help output
	h.parseFlagsToHelpFlags(p.subcommandContext.Flags, maxLength)

	// go through every flag in the parent parser and add it to help output
	h.parseFlagsToHelpFlags(p.Flags, maxLength)

	// formulate the usage string
	// first, we capture all the command and positional names by position
	commandsByPosition := make(map[int]string)
	for _, pos := range p.subcommandContext.PositionalFlags {
		if pos.Hidden {
			continue
		}
		if len(commandsByPosition[pos.Position]) > 0 {
			commandsByPosition[pos.Position] = commandsByPosition[pos.Position] + "|" + pos.Name
		} else {
			commandsByPosition[pos.Position] = pos.Name
		}
	}
	for _, cmd := range p.subcommandContext.Subcommands {
		if cmd.Hidden {
			continue
		}
		if len(commandsByPosition[cmd.Position]) > 0 {
			commandsByPosition[cmd.Position] = commandsByPosition[cmd.Position] + "|" + cmd.Name
		} else {
			commandsByPosition[cmd.Position] = cmd.Name
		}
	}

	// find the highest position count in the map
	var highestPosition int
	for i := range commandsByPosition {
		if i > highestPosition {
			highestPosition = i
		}
	}

	// only have a usage string if there are positional items
	var usageString string
	if highestPosition > 0 {
		// find each positional value and make our final string
		usageString = p.subcommandContext.Name
		for i := 1; i <= highestPosition; i++ {
			if len(commandsByPosition[i]) > 0 {
				usageString = usageString + " [" + commandsByPosition[i] + "]"
			} else {
				// dont keep listing after the first position without any properties
				// it will be impossible to reach anything beyond here anyway
				break
			}
		}
	}

	h.UsageString = usageString

}

// parseFlagsToHelpFlags parses the specified slice of flags into
// help flags on the the calling help command
func (h *Help) parseFlagsToHelpFlags(flags []*Flag, maxLength int) {

	for _, f := range flags {
		if f.Hidden {
			continue
		}

		// parse help values out if the flag hasn't been parsed yet
		if !f.parsed {
			f.parsed = true
			// parse the default value as a string and remember it for help output
			f.defaultValue, _ = f.returnAssignmentVarValueAsString()
		}

		// determine the default value based on the assignment variable
		defaultValue := f.defaultValue

		// dont show nils
		if defaultValue == "<nil>" {
			defaultValue = ""
		}

		// for bools, dont show a default of false
		_, isBool := f.AssignmentVar.(*bool)
		if isBool {
			b := f.AssignmentVar.(*bool)
			if *b == false {
				defaultValue = ""
			}
		}

		newHelpFlag := HelpFlag{
			ShortName:    f.ShortName,
			LongName:     f.LongName,
			Description:  f.Description,
			DefaultValue: defaultValue,
			Spacer:       makeSpacer(f.LongName, maxLength),
		}
		h.AddFlagToHelp(newHelpFlag)
	}
}

// AddFlagToHelp adds a flag to help output if it does not exist
func (h *Help) AddFlagToHelp(f HelpFlag) {
	for _, existingFlag := range h.Flags {
		if len(existingFlag.ShortName) > 0 && existingFlag.ShortName == f.ShortName {
			return
		}
		if len(existingFlag.LongName) > 0 && existingFlag.LongName == f.LongName {
			return
		}
	}
	h.Flags = append(h.Flags, f)
}

// getLongestNameLength takes a slice of any supported flag and returns the length of the longest of their names
func getLongestNameLength(slice interface{}, min int) int {
	var maxLength = min

	s := reflect.ValueOf(slice)
	if s.Kind() != reflect.Slice {
		log.Panicf("Paremeter given to getLongestNameLength() is of type %s. Expected slice", s.Kind())
	}

	for i := 0; i < s.Len(); i++ {
		option := s.Index(i).Interface()
		var name string
		switch t := option.(type) {
		case *Subcommand:
			name = t.Name
		case *Flag:
			name = t.LongName
		case *PositionalValue:
			name = t.Name
		default:
			log.Panicf("Unexpected type %T found in slice passed to getLongestNameLength(). Possible types: *Subcommand, *Flag, *PositionalValue", t)
		}
		length := len(name)
		if length > maxLength {
			maxLength = length
		}
	}

	return maxLength
}

// makeSpacer creates a string of whitespaces, with a length of the given
// maxLength minus the length of the given name
func makeSpacer(name string, maxLength int) string {
	length := maxLength - utf8.RuneCountInString(name)
	if length < 0 {
		length = 0
	}
	return strings.Repeat(" ", length)
}