gistfile1.txt

Setup:
// (actually this is module.exports)
var Prompt = new Blackbird(function (Promise) {
    function Prompt(opts, ctx) {
        this._opts = opts || { };
        
        // copy over initialization variables
        ctx = ctx || { };
        for (var key in ctx) {
            if (ctx.hasOwnProperty(key)) {
                this[key] = ctx[key];
            }
        }
    }
    
    Prompt.prototype.ask = function (res, msg, opts) {
        ..etc..
    };
    Prompt.prototype.etc...
    
    Promise.extend('ask');
    
    return Prompt;
});

----

Usage:

var prompt = new Prompt({}, {
    addrs: [ ],
    iface: null
});

prompt()
.ask('Interface to use:', {
    key: 'iface',
    validate: Object.keys(interfaces),
    default: 'eth0'
})

.ask('Add an IPv6 subnet?', {
    type: 'boolean',
    default: 'N',
    ifTrue: function () { return prompt().ask('Enter subnet:').then(addSubnet); }
})

.then(function () {
    var addrs = interfaces[this.iface];
    this.v4addrs = addrs.filter(function (a) {
        return a.family === 'IPv4' && a.internal === false;
    });
    this.v6addrs = addrs.filter(function (a) {
        return a.family === 'IPv6' && a.internal === false;
    });
})

.ask(function () {
    var count = this.v4addrs.length;
    return {
        type: 'boolean',
        question: 'Use ' + count + ' IPv4 addresses?',
        default: count <= 1 ? 'N' : 'Y',
        ifTrue: function () { this.addrs = this.addrs.concat(this.v4addrs); }
    };
})

.ask(function () {
    var count = this.v6addrs.length;
    return {
        type: 'boolean',
        question: 'Use ' + count + ' IPv6 addresses?',
        default: count <= 1 ? 'N' : 'Y',
        ifTrue: function () { this.addrs = this.addrs.concat(this.v6addrs); }
    };
})

.then(function () {
    console.log(this);
});