4.3 KiB
Developer Guide
Getting Started
The most simple example is below.
package main
import (
"fmt"
"github.com/c-bata/go-prompt"
)
// executor executes command and print the output.
func executor(in string) {
fmt.Println("Your input: " + in)
}
// completer returns the completion items from user input.
func completer(d prompt.Document) []prompt.Suggest {
s := []prompt.Suggest{
{Text: "users", Description: "user table"},
{Text: "sites", Description: "sites table"},
{Text: "articles", Description: "articles table"},
{Text: "comments", Description: "comments table"},
}
return prompt.FilterHasPrefix(s, d.GetWordBeforeCursor(), true)
}
func main() {
p := prompt.New(
executor,
completer,
prompt.OptionPrefix(">>> "),
prompt.OptionTitle("sql-prompt"),
)
p.Run()
}
If you want to create CLI using go-prompt, I recommend you to look at the source code of kube-prompt. It is the most practical example.
Options
go-prompt has many color options. It is difficult to describe by text. So please see below figure:
- OptionPrefixTextColor(prompt.Color) : default
prompt.Blue - OptionPrefixBackgroundColor(prompt.Color) : default
prompt.DefaultColor - OptionInputTextColor(prompt.Color) : default
prompt.DefaultColor - OptionInputBGColor(prompt.Color) : default
prompt.DefaultColor - OptionPreviewSuggestionTextColor(prompt.Color) : default
prompt.Green - OptionPreviewSuggestionBGColor(prompt.Color) : default
prompt.DefaultColor - OptionSuggestionTextColor(prompt.Color) : default
prompt.White - OptionSuggestionBGColor(prompt.Color) : default
prompt.Cyan - OptionSelectedSuggestionTextColor(prompt.Color) :
default prompt.Black - OptionSelectedSuggestionBGColor(prompt.Color) :
default prompt.DefaultColor - OptionDescriptionTextColor(prompt.Color) : default
prompt.Black - OptionDescriptionBGColor(prompt.Color) : default
prompt.Turquoise - OptionSelectedDescriptionTextColor(prompt.Color) : default
prompt.White - OptionSelectedDescriptionBGColor(prompt.Color) : default
prompt.Cyan - OptionScrollbarThumbColor :
prompt.DarkGray - OptionScrollbarBGColor :
prompt.Cyan
Other Options
OptionTitle(string) : default ""
Option to set a title that wll be displayed on the header bar of terminal.
OptionHistory([]string) : default []string{}
Option to set history.
OptionPrefix(string) : default "> "
Option to set prefix string.
OptionLivePrefix(func() (prefix string, useLivePrefix bool)) : default nil
Option to set a callback function for updating prefix string dynamically.
OptionMaxSuggestions(x uint16) : default 6
The max number of displayed suggestions.
OptionParser(prompt.ConsoleParser) : default VT100Parser
To set a custom ConsoleParser object. The argument should implement ConsoleParser interface.
OptionWriter(prompt.ConsoleWriter) : default VT100Writer
To set a custom ConsoleWriter object. The argument should implement ConsoleWriter interface.
SwitchKeyBindMode(prompt.KeyBindMode) : default prompt.EmacsKeyBindMode
To set a key bind mode.
OptionAddKeyBind(...KeyBind) : default []KeyBind{}
To set a custom key bind.
Architecture of go-prompt
Caution: This section is WIP.
This is a short description of go-prompt implementation. go-prompt consists of three parts.
- Input parser
- Emulate user input with Buffer object.
- Render buffer object.
Input Parser
Input Parser only supports vt100-compatible console now.
- Set as the raw mode.
- Read a standard input.
- Parse to byte array
Emulate user input
go-prompt contains Buffer class. It represents input state by handling a key input by user.
Buffer object has text and cursor position.
TODO prepare the sample of buffer
package main
import "github.com/c-bata/go-prompt"
func main() {
b := prompt.NewBuffer()
... wip
}
Renderer
Renderer object renders a buffer object.
TODO prepare the sample of brender
package main
the output is below:
TODO prepare a screen shot