inquirer

What is inquirer?

The inquirer npm package is a collection of common interactive command line user interfaces. It provides an easy way to capture user input in a variety of ways such as lists, confirmations, and text input, which are useful for building command-line tools and scripts.

What are inquirer's main functionalities?

Text Input

Captures freeform text input from the user.

const inquirer = require('inquirer');
inquirer.prompt([{ type: 'input', name: 'username', message: 'What is your username?' }]).then(answers => { console.log(`Hello, ${answers.username}!`); });

Confirmation

Asks the user a yes/no question.

const inquirer = require('inquirer');
inquirer.prompt([{ type: 'confirm', name: 'continue', message: 'Do you wish to continue?' }]).then(answers => { console.log(`You chose to ${answers.continue ? 'continue' : 'stop'}.`); });

List

Presents a list of options for the user to choose from.

const inquirer = require('inquirer');
inquirer.prompt([{ type: 'list', name: 'selection', message: 'Choose an option:', choices: ['Option 1', 'Option 2', 'Option 3'] }]).then(answers => { console.log(`You selected: ${answers.selection}`); });

Checkbox

Allows the user to select multiple options from a list.

const inquirer = require('inquirer');
inquirer.prompt([{ type: 'checkbox', name: 'features', message: 'What features do you want?', choices: ['Feature A', 'Feature B', 'Feature C'] }]).then(answers => { console.log(`You selected: ${answers.features.join(', ')}`); });

Password

Asks the user for a password, input is hidden on the terminal.

const inquirer = require('inquirer');
inquirer.prompt([{ type: 'password', name: 'password', message: 'Enter your password:' }]).then(answers => { console.log('Password captured'); });

Other packages similar to inquirer

prompt

Prompt is another command-line input collector with a slightly different API. It has a simpler interface but lacks some of the more advanced features and UI components that inquirer provides.

enquirer

Enquirer is a stylish, minimal alternative to inquirer with a more modern promise-based API. It offers similar functionality but with a focus on being lightweight and fast.

vorpal

Vorpal is a framework for building interactive CLI applications. It includes a command-line interface with a suite of interactive prompts, but it's more focused on building the entire CLI tool rather than just handling prompts.

README

Inquirer.js

A collection of common interactive command line user interfaces.

Goal and philosophy

We strive at providing easily embeddable and beatiful command line interface for Node.js ; some hope in becoming the CLI Xanadu.

Inquirer should ease the process of asking end user questions, parsing, validating answers, and providing error feedback.

Inquirer provide the user interface, and the inquiry session flow. If you're searching for a full blown command line program utility, then check out Commander.js (inspired by) or Cli-color (used internally).

Documentation

Installation

npm install inquirer

var inquirer = require("inquirer");
inquirer.prompt([/* Pass your questions in here */], function( answers ) {
	// Use user feedback for... whatever!!
});

Examples (Run it and see it)

Checkout the examples/ folder for code and interface examples.

node examples/pizza.js
# etc

Methods

inquirer.prompt( questions, callback )

Launch the prompt interface (inquiry session)

• questions (Array) containing Question Object
• callback (Function) first parameter is the Answers Object

Objects

Question

A question object is a hash containing question related values:

• type: (String) Type of the prompt. Defaults: input - Possible values: input, confirm, list, rawlist
• name: (String) The name to use when storing the answer in the anwers hash.
• message: (String) The question to print.
• default: (String) Default value to use if nothing is entered
• choices: (Array) Choices array.
  Values can be simple strings, or objects containing a name (to display) and a value properties (to save in the answers hash).
• validate: (Function) Receive the user input and should return true if the value is valid, and an error message (String) otherwise. If false is returned, a default error message is provided.
• filter: (Function) Receive the user input and return the filtered value to be used inside the program. The value returned will be added to the Answers hash.
• when: (Function) Receive the current user answers hash and should return true or false depending on wheter or not this question should be asked.

validate, filter and when functions can be asynchronously using this.async(). You just have to pass the value you'd normally return to the callback option.

{
  validate: function(input) {

    // Declare function as asynchronous, and save the done callback
    var done = this.async();

    // Do async stuff
    setTimeout(function() {
      if (typeof input !== "number") {
        // Pass the return value in the done callback
        done("You need to provide a number");
        return;
      }
      // Pass the return value in the done callback
      done(true);
    }, 3000);
  }
}

Answers

A key/value hash containing the client answers in each prompt.

• Key The name property of the question object
• Value (Depends on the prompt)
  • confirm: (Boolean)
  • input : User input (filtered if filter is defined) (String)
  • rawlist, list : Selected choice value (or name if no value specified) (String)

Prompts

List - { type: "list" }

Take type, name, message, choices[, default, filter] properties. (Note that default must the choice index in the array)

[?] What about the toping: (Use arrow key)
  [X] Peperonni and chesse
  [ ] All dressed
  [ ] Hawaïan

Raw List - { type: "rawlist" }

Take type, name, message, choices[, default, filter] properties. (Note that default must the choice index in the array)

[?] You also get a free 2L liquor: 
  1) Pepsi
  2) 7up
  3) Coke
  Answer: 

Confirm - { type: "confirm" }

Take type, name, message[, default] properties.

[?] Is it for a delivery: (Y/n)

Input - { type: "input" }

Take type, name, message[, default, filter, validate] properties.

[?] Any comments on your purchase experience: (Nope, all good!)

News on the march (Release notes)

• 0.1.7 : Add a hierarchical prompt API with when, allow lists from having a default
• 0.1.6 : Fix bug on unix and minor enhancement
• 0.1.5 : Enhance visual style; prompts are now more succint. Lots of bug fixes.
• 0.1.3 : Add async support for validation and filtering functions.
• 0.1.0 : First official release. There's 4 prompt types: input, confirm, list and rawlist. There's functionnality to allow the validation of input, and the filtering of values.

Contributing

Style Guide: Please base yourself on Idiomatic.js style guide with two space indent
Unit test: Unit test are wrote in Mocha. Please add a unit test for every new feature or bug fix. npm test to run the test suite.
Documentation: Add documentation for every API change. Feel free to send corrections or better docs!

License

Copyright (c) 2012 Simon Boudrias
Licensed under the MIT license.