when_aggregate

var redis = require('redis');
var client = redis.createClient();
var pg = require('pg');
var async = require('async');
var _ = require('underscore');
var when = require('when');

connect("tcp://erp:erp@localhost/poc")
    .then(getFeedFromRedis)
    .then(getReport)
    .then(getComment)
    .then(function(result) {
        console.log(result);
        client.quit();
        conn.end();
    });

var conn;

function connect(uri) {
    conn = new pg.Client(uri);
    var deferred = when.defer();
    conn.connect(function(err) {
        deferred.resolve();
    });
    return deferred.promise;
}

function getFeedFromRedis() {
    var deferred = when.defer();
    client.zrange("c1", 0, -1, function(err, results) {
        deferred.resolve(results);
    });
    return deferred.promise;
}

function getReport(ids) {
    return when.map(ids, function(id) {
        var deferred = when.defer();
        conn.query('select title from report where id = $1', [id], function(err, result) {
            deferred.resolve({
                id: id,
                title: result.rows[0].title
            });
        });
        return deferred.promise;
    });
}

function getComment(reports) {
    return when.map(reports, function(report) {
        var deferred = when.defer();
        conn.query('select id, title from comment where report_id = $1', [report.id], function(err, result) {
            report.comments = result.rows;
            deferred.resolve(report);
        })
        return deferred.promise;
    })
}