accumulator_getSpecificNodeByQuarter.js

// FIRST APPROACH: USE AN ACCUMULATOR.

function accumulator_getSpecificNodeByQuarter(givenNodeID, quarter) {
    // because this analytics is fixed I check the first quarter
    var quarterlyResults = [];
    dbA.utilization.find({nodeID: givenNodeID}, {_id: 0, day: 1, spaces: 1}, function (err, docs) {
        if (err) return console.log('did not find node');
        // set min and max
        var minday;
        var maxday;
        // set the fiscal quarters
        if (quarter === "1") {
            minday = new Date('2015-01-01');
            maxday = new Date('2015-03-31');
        } else if (quarter==="2") {
            minday = new Date('2015-04-01');
            maxday = new Date('2015-06-31');
        } else if (quarter ==="3") {
            minday = new Date('2015-06-01');
            maxday = new Date('2015-09-31');
        } else if (quarter ==="4") {
            minday = new Date('2015-10-01');
            maxday = new Date('2015-12-31');
        } else {
            minday = new Date('2016-01-01');
            maxday = new Date('2016-03-31');
        }
        for (var i = 0; i < docs.length; i++) {
            // figure out the day in database
            var today = new Date(docs[i].day);

            // is it in the quarter and also a weekday?
            if (today >= minday && today <= maxday && today.getDay() >=1 && today.getDay() <=5){
                var thisSpace = docs[i].spaces;
                for (var ii = 0; ii < thisSpace.length; ++ii) {

                    quarterlyResults.push({'day': docs[i].day, 'name': thisSpace[ii].name, 'stats': statsForUtils(thisSpace[ii].util)})
                }
            }
        }
    });
    // this works as long as find() has completed by the time the
    // execution flow reaches these commands...
    console.log("quarterlyResults:", quarterlyResults);
    console.log("quarterlyResults[0]:", quarterlyResults[0]);
}

callback_getSpecificNodeByQuarter.js

// SECOND APPROACH (usually better): USE A CALLBACK.

// "callback" is the function that executes AFTER the find is complete
function callback_getSpecificNodeByQuarter(givenNodeID, quarter, callback) {
    // because this analytics is fixed I check the first quarter
    dbA.utilization.find({nodeID: givenNodeID}, {_id: 0, day: 1, spaces: 1}, function (err, docs) {
        if (err) {
            console.log('did not find node');
            return callback(err);
        }
        var quarterlyResults = [];
        // set min and max
        var minday;
        var maxday;
        // set the fiscal quarters
        if (quarter === "1") {
            minday = new Date('2015-01-01');
            maxday = new Date('2015-03-31');
        } else if (quarter==="2") {
            minday = new Date('2015-04-01');
            maxday = new Date('2015-06-31');
        } else if (quarter ==="3") {
            minday = new Date('2015-06-01');
            maxday = new Date('2015-09-31');
        } else if (quarter ==="4") {
            minday = new Date('2015-10-01');
            maxday = new Date('2015-12-31');
        } else {
            minday = new Date('2016-01-01');
            maxday = new Date('2016-03-31');
        }
        for (var i = 0; i < docs.length; i++) {
            // figure out the day in database
            var today = new Date(docs[i].day);

            // is it in the quarter and also a weekday?
            if (today >= minday && today <= maxday && today.getDay() >=1 && today.getDay() <=5){
                var thisSpace = docs[i].spaces;
                for (var ii = 0; ii < thisSpace.length; ++ii) {

                    quarterlyResults.push({'day': docs[i].day, 'name': thisSpace[ii].name, 'stats': statsForUtils(thisSpace[ii].util)})
                }
            }
        }
        callback(null, quarterlyResults);
    });
}

// example callback
function writeResultsToFile(err, results) {
    if (err) return console.error("writeResultsToFile:", err);
    require("fs").writeFile("quarterlyResults.dat", results, function (err) {
        if (err) return console.error("writeFile:", err);
        console.log("Wrote file successfully :)");
    });
}

// and here's the actual function call, using the callback
callback_getSpecificNodeByQuarter(givenNodeID, quarter, writeResultsToFile);