| Current File : //lib/node_modules/bower/lib/node_modules/promptly/README.md |
# promptly
[](http://travis-ci.org/IndigoUnited/node-promptly.png)
Simple command line prompting utility.
## Installation
`$ npm install promptly`
## API
Note that the `options` argument is optional for all the commands.
### .prompt(message, opts, fn)
Prompts for a value, printing the `message` and waiting for the input.
When done, calls `fn` with `error` and `value`.
Default options:
```js
{
// 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,
// Input and output streams to read and write to
'input': process.stdin,
'output': process.stdout
}
```
The validators have two purposes:
```js
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:
```js
promptly.prompt('Name: ', function (err, value) {
// err is always null in this case, because no validators are set
console.log(value);
});
```
Ask for a name with a constraint (non-empty value and length > 2):
```js
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:
```js
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:', e.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:
```js
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:
```js
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:
```js
promptly.password('Type a password: ', function (err, value) {
console.log('Password is:', value);
});
```
## License
Released under the [MIT License](http://www.opensource.org/licenses/mit-license.php).