External REST via cURL GET

ID [ recurring_timer::1       ]

{
"click": "to edit",
"with JSON": "there are no reserved field names"
}

{
  "type": "recurring_timer",
  "id": 1,
  "active": false
}

function CreateRecurringTimer(context) {
    log('From CreateRecurringTimer: creating timer', context.mode, context.id);
    var nextSchedule = null;
    if (context.mode === "via_onupdate") {
        // Create a timestamp 30 seconds from now for the initial Timer
        var thirtySecFromNow = new Date(); // Get current time & add 30 sec. to it.
        thirtySecFromNow.setSeconds(thirtySecFromNow.getSeconds() + 30);
        nextSchedule = thirtySecFromNow;
    } else {
        // must be: context.mode === "via_callback"
        // Create UTC timestamp to fire a Timer for tomorrow do this for timers 2 to N
        var tomorrow = new Date();
        tomorrow.setHours(0,0,0,0);
        tomorrow.setDate(tomorrow.getDate() + 1);
        nextSchedule = tomorrow;
    }
    log("Finish CreateRecurringTimer (local time) nextSchedule", localISOTime(nextSchedule));
    createTimer(RecurringTimerCallback, nextSchedule, context.id, context);
}

function localISOTime (indate) {
    // JavaScript works with dates as UTC times, but sometimes we prefer to see local time
    return new Date(indate.getTime() - indate.getTimezoneOffset() * 60 * 1000)
        .toISOString().split(/[TZ]/).slice(0, 2).join('T');
}

function RecurringTimerCallback(context) {
    log('From RecurringTimerCallback: timer fired', context);
    // do any sort of recurring work here, just update a date_stamp in a doc
    var now = new Date();
    var nowLoc = localISOTime(now);
    var dt_beg = now.getTime();
    // Generate a YYYY-MM-DD string in UTC for Yesterday
    var yesterday = new Date();
    yesterday.setHours(0,0,0,0);
    yesterday.setDate(yesterday.getDate() - 1);
    var apiReqDateUtc = yesterday.toISOString().substring(0, 10);
    // Generate a YYYY-MM-DD string in Local Time for Yesterday
    var apiReqDateLoc = localISOTime(yesterday).substring(0, 10);
    try {
        // ==============================
        // Perform a cURL GET here
        var request = {
            path: apiReqDateUtc
        };
        //  perform the cURL request using the URL alias form the settings
        var response = curl('GET', exchangeRateApi, request);
        var status = "OKAY";
        if (response.status != 200 && response.status != 302) {
            status = "FAIL";
        }
        // ==============================
        var curl_time_ms = new Date().getTime() - dt_beg;
        log('USER FUNCTION DONE ' + status +
            ' (curl ' + response.status + ' took ' + curl_time_ms + ' ms.)');
        if (response && response.body && response.body.date && response.body.base) {
            // write our exchange lookup table document, we will do this 365 times a year
            src_col["exchange::" + response.body.date] = response.body;

            // write status doc - we succeeded
            src_col["cur_" + context.id] = {
                "last_update_loc": nowLoc,
                "last_update_utc": now, "apiReqDateUtc": apiReqDateUtc,
                "curl_success": true,  "valid": true, "curl_time_ms": curl_time_ms
            };

        } else {
            // write status doc - we failed
            src_col["cur_" + context.id] = {
                "last_update_loc": nowLoc,
                "last_update_utc": now, "apiReqDateUtc": apiReqDateUtc,
                "curl_success": true, "body_valid": false,  "curl_time_ms": curl_time_ms
            };
        }
    } catch (e) {
        var curl_time_ms = new Date().getTime() - dt_beg;
        log('USER FUNCTION DONE ' + status +
            ' (curl ERROR ' + e + ' took ' + curl_time_ms + ' ms.)');
        // write status doc - we failed
        src_col["cur_" + context.id] = {
            "last_update_loc": nowLoc,
            "last_update_utc": now, "apiReqDateUtc": apiReqDateUtc,
            "curl_success": false, "body_valid": false, "curl_time_ms": curl_time_ms
        };
    }
    // rearm the timer
    CreateRecurringTimer({ "id": context.id, "mode": "via_callback" })
}

function OnUpdate(doc, meta) {
    // You would typically filter to mutations of interest
    if (doc.type !== 'recurring_timer') return;
    if (doc.active === false) {
        if (cancelTimer(RecurringTimerCallback, meta.id)) {
            log('From OnUpdate: canceled active Timer, doc.active', doc.active, meta.id);
        } else {
            log('From OnUpdate: no active Timer to cancel, doc.active', doc.active, meta.id);
        }
    } else {
        log('From OnUpdate: create/overwrite doc.active', doc.active, meta.id);
        CreateRecurringTimer({  "id": meta.id, "mode": "via_onupdate" });
    }
}