console

Documentation

Overview

Copyright 2018 DREP Foundation Ltd. This file is part of the drep-cli library.

The drep-cli library is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

The drep-cli library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the drep-cli library. If not, see <http://www.gnu.org/licenses/>.

Index

• Constants
• Variables
• type Config
• type Console
  • func New(config Config) (*Console, error)
  • func (c *Console) AutoCompleteInput(line string, pos int) (string, []string, string)
  • func (c *Console) Evaluate(statement string) error
  • func (c *Console) Execute(path string) error
  • func (c *Console) Interactive(exitCh chan struct{})
  • func (c *Console) Stop(graceful bool) error
  • func (c *Console) Welcome()
• type UserPrompter
• type WordCompleter

Constants

const DefaultPrompt = "> "

DefaultPrompt is the default prompt line prefix to use for user input querying.

const HistoryFile = "history"

HistoryFile is the file within the data directory to store input scrollback.

const RPC_JS = `` /* 151-byte string literal not displayed */

Variables

var Modules = map[string]string{

	"rpc": RPC_JS,
}

var Stdin = newTerminalPrompter()

Stdin holds the stdin line reader (also using stdout for printing prompts). Only this reader may be used for input because it keeps an internal buffer.

Types

type Config

type Config struct {
	HomeDir  string       `json:"homeDir"`  // Data directory to store the console history at
	DocRoot  string       `json:"docRoot"`  // Filesystem path from where to load JavaScript files from
	Client   *rpc.Client  `json:"client"`   // RPC client to execute Ethereum requests through
	Prompt   string       `json:"prompt"`   // Input prompt prefix string (defaults to DefaultPrompt)
	Prompter UserPrompter `json:"prompter"` // Input prompter to allow interactive user feedback (defaults to TerminalPrompter)
	Printer  io.Writer    `json:"printer"`  // Output writer to serialize any display strings to (defaults to os.Stdout)
	Preload  []string     `json:"preload"`  // Absolute paths to JavaScript files to preload
}

Config is the collection of configurations to fine tune the behavior of the JavaScript console.

type Console

type Console struct {
	// contains filtered or unexported fields
}

Console is a JavaScript interpreted runtime environment. It is a fully fledged JavaScript console attached to a running node via an external or in-process RPC client.

func New

func New(config Config) (*Console, error)

New initializes a JavaScript interpreted runtime environment and sets defaults with the config struct.

func (*Console) AutoCompleteInput

func (c *Console) AutoCompleteInput(line string, pos int) (string, []string, string)

AutoCompleteInput is a pre-assembled word completer to be used by the user input prompter to provide hints to the user about the methods available.

func (*Console) Evaluate

func (c *Console) Evaluate(statement string) error

Evaluate executes code and pretty prints the result to the specified output stream.

func (*Console) Execute

func (c *Console) Execute(path string) error

Execute runs the JavaScript file specified as the argument.

func (*Console) Interactive

func (c *Console) Interactive(exitCh chan struct{})

Interactive starts an interactive user session, where input is propted from the configured user prompter.

func (*Console) Stop

func (c *Console) Stop(graceful bool) error

Stop cleans up the console and terminates the runtime environment.

func (*Console) Welcome

func (c *Console) Welcome()

Welcome show summary of current Drep instance and some metadata about the console's available modules.

type UserPrompter

type UserPrompter interface {
	// PromptInput displays the given prompt to the user and requests some textual
	// data to be entered, returning the input of the user.
	PromptInput(prompt string) (string, error)

	// PromptPassword displays the given prompt to the user and requests some textual
	// data to be entered, but one which must not be echoed out into the terminal.
	// The method returns the input provided by the user.
	PromptPassword(prompt string) (string, error)

	// PromptConfirm displays the given prompt to the user and requests a boolean
	// choice to be made, returning that choice.
	PromptConfirm(prompt string) (bool, error)

	// SetHistory sets the input scrollback history that the prompter will allow
	// the user to scroll back to.
	SetHistory(history []string)

	// AppendHistory appends an entry to the scrollback history. It should be called
	// if and only if the prompt to append was a valid command.
	AppendHistory(command string)

	// ClearHistory clears the entire history
	ClearHistory()

	// SetWordCompleter sets the completion function that the prompter will call to
	// fetch completion candidates when the user presses tab.
	SetWordCompleter(completer WordCompleter)
}

UserPrompter defines the methods needed by the console to prompt the user for various types of inputs.

type WordCompleter

type WordCompleter func(line string, pos int) (string, []string, string)

WordCompleter takes the currently edited line with the cursor position and returns the completion candidates for the partial word to be completed. If the line is "Hello, wo!!!" and the cursor is before the first '!', ("Hello, wo!!!", 9) is passed to the completer which may returns ("Hello, ", {"world", "Word"}, "!!!") to have "Hello, world!!!".