class RandomWatchFaceViewClass {
    // ...
    function initialize() {
        //...
        if (hasComps) {
            stepId = new Id(Complications.COMPLICATION_TYPE_STEPS);
            batId = new Id(Complications.COMPLICATION_TYPE_BATTERY);
            calId = new Id(Complications.COMPLICATION_TYPE_CALENDAR_EVENTS);
        }
        stepComp = Complications.getComplication(stepId);
        if (stepComp != null) {
            Complications.subscribeToUpdates(stepId);
        }
        batComp = Complications.getComplication(batId);
        if (batComp != null) {
            Complications.subscribeToUpdates(batId);
        }
        calComp = Complications.getComplication(calId);
        if (calComp != null) {
            Complications.subscribeToUpdates(calId);
        }

        Complications.registerComplicationChangeCallBack(method(:onComplicationChanged));
    }

    // Callback method which will be called by the system whenever
    // any of the subscribed complications is changes
    function onComplicationChanged(id as Complication.id) as Void {
        if (id == stepId) {
            updateStepsValue();
        } else if (id == batId) {
            updateBatValue();
        } else if (id == calComp) {
            updateCalendarValue();
        }
    }

    var batLoad;
    function updateBatValue() {
        if (hasComps) {
            batLoad = Complications.getComplication(batId).value;
        } else {
            batLoad = ((System.getSystemStats().battery) + 0.5).toNumber();
        }
    }
    function updateStepsValue() {
        // similar to above
    }
    function updateCalValue() {
        // similar to above
    }

    function onUpdate(dc) {
        // If we have complications, thre's no point in calling these functions,
        // as they're already called when complications change
        if (!hasComps) {
            updateStepsValue();
            updateBatValue();
            updateCalValue();
        }

        var batString = Lang.format("$1$", [batLoad])+"%";
        var stepsString = ... // similar to the above
        var calString = ... // similar to the above

        // code which actually draws batString, stepsString, calString to the dc:
    }
}