odin-javascript-exercises/node_modules/inquirer/lib/prompts/base.js
2017-12-15 12:56:14 -06:00

139 lines
3.4 KiB
JavaScript

/**
* Base prompt implementation
* Should be extended by prompt types.
*/
var _ = require('lodash');
var chalk = require('chalk');
var runAsync = require('run-async');
var Choices = require('../objects/choices');
var ScreenManager = require('../utils/screen-manager');
var Prompt = module.exports = function (question, rl, answers) {
// Setup instance defaults property
_.assign(this, {
answers: answers,
status: 'pending'
});
// Set defaults prompt options
this.opt = _.defaults(_.clone(question), {
validate: function () {
return true;
},
filter: function (val) {
return val;
},
when: function () {
return true;
},
suffix: '',
prefix: chalk.green('?')
});
// Check to make sure prompt requirements are there
if (!this.opt.message) {
this.throwParamError('message');
}
if (!this.opt.name) {
this.throwParamError('name');
}
// Normalize choices
if (Array.isArray(this.opt.choices)) {
this.opt.choices = new Choices(this.opt.choices, answers);
}
this.rl = rl;
this.screen = new ScreenManager(this.rl);
};
/**
* Start the Inquiry session and manage output value filtering
* @return {Promise}
*/
Prompt.prototype.run = function () {
return new Promise(function (resolve) {
this._run(function (value) {
resolve(value);
});
}.bind(this));
};
// default noop (this one should be overwritten in prompts)
Prompt.prototype._run = function (cb) {
cb();
};
/**
* Throw an error telling a required parameter is missing
* @param {String} name Name of the missing param
* @return {Throw Error}
*/
Prompt.prototype.throwParamError = function (name) {
throw new Error('You must provide a `' + name + '` parameter');
};
/**
* Called when the UI closes. Override to do any specific cleanup necessary
*/
Prompt.prototype.close = function () {
this.screen.releaseCursor();
};
/**
* Run the provided validation method each time a submit event occur.
* @param {Rx.Observable} submit - submit event flow
* @return {Object} Object containing two observables: `success` and `error`
*/
Prompt.prototype.handleSubmitEvents = function (submit) {
var self = this;
var validate = runAsync(this.opt.validate);
var filter = runAsync(this.opt.filter);
var validation = submit.flatMap(function (value) {
return filter(value, self.answers).then(function (filteredValue) {
return validate(filteredValue, self.answers).then(function (isValid) {
return {isValid: isValid, value: filteredValue};
}, function (err) {
return {isValid: err};
});
}, function (err) {
return {isValid: err};
});
}).share();
var success = validation
.filter(function (state) {
return state.isValid === true;
})
.take(1);
var error = validation
.filter(function (state) {
return state.isValid !== true;
})
.takeUntil(success);
return {
success: success,
error: error
};
};
/**
* Generate the prompt question string
* @return {String} prompt question string
*/
Prompt.prototype.getQuestion = function () {
var message = this.opt.prefix + ' ' + chalk.bold(this.opt.message) + this.opt.suffix + chalk.reset(' ');
// Append the default if available, and if question isn't answered
if (this.opt.default != null && this.status !== 'answered') {
message += chalk.dim('(' + this.opt.default + ') ');
}
return message;
};