external-editor

What is external-editor?

The external-editor npm package allows you to easily invoke and manage external text editors from within your Node.js applications. It is particularly useful when you need to allow users to edit large multi-line texts, which can be cumbersome to handle within a command-line interface. The package takes care of launching the editor, capturing the text once the editor is closed, and handling temporary files.

What are external-editor's main functionalities?

Launch an external editor and get the edited text

This feature launches the default system editor, waits for the user to make changes and save, and then returns the edited text.

const { edit } = require('external-editor');

const text = edit();
console.log(text);

Launch an external editor with predefined text

This feature allows you to launch an external editor with predefined text, which the user can then edit.

const { edit } = require('external-editor');

const initialText = 'Initial content of the file.';
const text = edit(initialText);
console.log(text);

Create an instance of ExternalEditor

This feature provides more control by creating an instance of ExternalEditor, which can be used to run the editor and clean up temporary files manually.

const { ExternalEditor } = require('external-editor');

const editor = new ExternalEditor();
const text = editor.run();
editor.cleanup();
console.log(text);

Other packages similar to external-editor

inquirer

Inquirer is a comprehensive library for creating interactive command-line interfaces. While it does not directly provide functionality to launch external editors, it offers a wide range of input types, including an 'editor' input type that allows users to input multi-line text using an embedded editor.

open

The 'open' package is used to open files or URLs in the user's preferred application. While it is not specifically designed for text editing, it can be used to open text files in the default editor. However, it does not manage the editing process or handle temporary files like external-editor does.

enquirer

Enquirer is another library for creating stylish command-line interfaces with various prompts. Similar to Inquirer, it includes a prompt type for editing text, but it does not specifically focus on launching external editors or managing temporary files.

README

External Editor

A node module to edit a string with a users preferred text editor using $VISUAL or $ENVIRONMENT.

Version: 3.1.0

As of version 3.0.0, the minimum version of node supported is 4.

Install

npm install external-editor --save

Usage

A simple example using the .edit convenience method

import {edit} from "external-editor";
const data = edit('\n\n# Please write your text above');
console.log(data);

A full featured example

import {ExternalEditor, CreateFileError, ReadFileError, RemoveFileError} from "external-editor"

try {
    const editor = new ExternalEditor();
    const text = editor.run() // the text is also available in editor.text
    
    if (editor.last_exit_status !== 0) {
        console.log("The editor exited with a non-zero code");
    }
} catch (err) {
    if (err instanceOf CreateFileError) {
        console.log('Failed to create the temporary file');
    } else if (err instanceOf ReadFileError) {
        console.log('Failed to read the temporary file');
    } else if (err instanceOf LaunchEditorError) {
        console.log('Failed to launch your editor');
    } else {
        throw err;
    }
}

// Do things with the text

// Eventually call the cleanup to remove the temporary file
try {
    editor.cleanup();   
} catch (err) {
     if (err instanceOf RemoveFileError) {
         console.log('Failed to remove the temporary file');
     } else {
        throw err
    }
}

API

Convenience Methods

• edit(text, config)
  • text (string) Optional Defaults to empty string
  • config (Config) Optional Options for temporary file creation
  • Returns (string) The contents of the file
  • Could throw CreateFileError, ReadFileError, or LaunchEditorError, or RemoveFileError
• editAsync(text, callback, config)
  • text (string) Optional Defaults to empty string
  • callback (function (error, text))
    • error could be of type CreateFileError, ReadFileError, or LaunchEditorError, or RemoveFileError
    • text(string) The contents of the file
  • config (Config) Optional Options for temporary file creation

Errors

• CreateFileError Error thrown if the temporary file could not be created.
• ReadFileError Error thrown if the temporary file could not be read.
• RemoveFileError Error thrown if the temporary file could not be removed during cleanup.
• LaunchEditorError Error thrown if the editor could not be launched.

External Editor Public Methods

• new ExternalEditor(text, config)
  • text (string) Optional Defaults to empty string
  • config (Config) Optional Options for temporary file creation
  • Could throw CreateFileError
• run() Launches the editor.
  • Returns (string) The contents of the file
  • Could throw LaunchEditorError or ReadFileError
• runAsync(callback) Launches the editor in an async way
  • callback (function (error, text))
    • error could be of type ReadFileError or LaunchEditorError
    • text(string) The contents of the file
• cleanup() Removes the temporary file.
  • Could throw RemoveFileError

External Editor Public Properties

• text (string) readonly The text in the temporary file.
• editor.bin (string) The editor determined from the environment.
• editor.args (array) Default arguments for the bin
• tempFile (string) Path to temporary file. Can be changed, but be careful as the temporary file probably already exists and would need be removed manually.
• lastExitStatus (number) The last exit code emitted from the editor.

Config Options

• prefix (string) Optional A prefix for the file name.
• postfix (string; Optional A postfix for the file name. Useful if you want to provide an extension.
• mode (number) Optional Which mode to create the file with. e.g. 644
• template (string) Optional A template for the filename. See tmp.
• dir (string) Optional Which path to store the file.

Errors

All errors have a simple message explaining what went wrong. They all also have an originalError property containing the original error thrown for debugging purposes.

Why Synchronous?

Everything is synchronous to make sure the editor has complete control of the stdin and stdout. Testing has shown async launching of the editor can lead to issues when using readline or other packages which try to read from stdin or write to stdout. Seeing as this will be used in an interactive CLI environment, I made the decision to force the package to be synchronous. If you know a reliable way to force all stdin and stdout to be limited only to the child_process, please submit a PR.

If async is really needed, you can use editAsync or runAsync. If you are using readline or have anything else listening to the stdin or you write to stdout, you will most likely have problem, so make sure to remove any other listeners on stdin, stdout, or stderr.

Demo

Breaking Changes from v2 to v3

• NodeJS 0.12 support dropped.
• Switched to named imports.
• All "snake_cased" variables and properties are now "camelCased".
  • ExternalEditor.temp_file is now ExternalEditor.tempFile.
  • ExternalEditor.last_exit_status is now ExternalEditor.lastExitStatus.
  • Error.original_error is now Error.originalError.

License

The MIT License (MIT)

Copyright (c) 2016-2018 Kevin Gravier

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.