4.6 KiB
promptly
Simple command line prompting utility.
Installation
$ npm install promptly
API
.prompt(message, [opts], [fn])
Prompts for a value, printing the message
and waiting for the input.
When done, calls fn
with error
and value
or returns a Promise
if no fn
is provided.
Default options:
{
// The default value. If not supplied, the input is mandatory
'default': null,
// Automatically trim the input
'trim': true,
// A validator or an array of validators.
'validator': null,
// Automatically retry if a validator fails
'retry': true,
// Do not print what the user types
'silent': false,
// Replace each character with the specified string when 'silent' is true
'replace': '',
// Input and output streams to read and write to
'input': process.stdin,
'output': process.stdout
}
The validators have two purposes:
function (value) {
// Validation example, throwing an error when invalid
if (value.length !== 2) {
throw new Error('Length must be 2');
}
// Parse the value, modifying it
return value.replace('aa', 'bb');
}
Example usages
Ask for a name:
promptly.prompt('Name: ', function (err, value) {
// err is always null in this case, because no validators are set
console.log(value);
});
Using Promise:
promptly.prompt('Name: ')
.then(function (value) {
// no need for catch in this case, because no validators are set
console.log(value);
});
Ask for a name with a constraint (non-empty value and length > 2):
var validator = function (value) {
if (value.length < 2) {
throw new Error('Min length of 2');
}
return value;
};
promptly.prompt('Name: ', { validator: validator }, function (err, value) {
// Since retry is true by default, err is always null
// because promptly will be prompting for a name until it validates
// Between each prompt, the error message from the validator will be printed
console.log('Name is:', value);
});
Same as above but do not retry automatically:
var validator = function (value) {
if (value.length < 2) {
throw new Error('Min length of 2');
}
return value;
};
promptly.prompt('Name: ', { validator: validator, retry: false }, function (err, value) {
if (err) {
console.error('Invalid name:', err.message);
// Manually call retry
// The passed error has a retry method to easily prompt again.
return err.retry();
}
console.log('Name is:', value);
});
.confirm(message, [opts], fn)
Ask the user to confirm something.
Calls fn
with error
and value
(true or false).
Truthy values are: y
, yes
and 1
.
Falsy values are n
, no
, and 0
.
Comparison is made in a case insensitive way.
Example usage:
promptly.confirm('Are you sure? ', function (err, value) {
console.log('Answer:', value);
});
.choose(message, choices, [opts], fn)
Ask the user to choose between multiple choices
(array of choices).
Calls fn
with error
and value
.
Example usage:
promptly.choose('Do you want an apple or an orange? ', ['apple', 'orange'], function (err, value) {
console.log('Answer:', value);
});
.password(message, [opts], fn)
Prompts for a password, printing the message
and waiting for the input.
When available, calls fn
with error
and value
.
The available options are the same, except that trim
and silent
default to false
and default
is an empty string (to allow empty passwords).
Example usage:
promptly.password('Type a password: ', { replace: '*' }, function (err, value) {
console.log('Password is:', value);
});
License
Released under the MIT License.