EventHandler.js

/** Author
 *           Name: Marthinus Ettienne
 *        Surname: van Zyl
 * Student Number: u19012366
 */

// Task 1:

function EventHandler(array){
    this.array = array;
}

EventHandler.prototype.getEventsBetweenDates = function (start, end){
    var startDate = Date.parse(start);
    var endDate = Date.parse(end);
    var startFromDateFilteredArray = this.array.filter((e) => {
        return Date.parse(e.dateStart) >= startDate;
    });
    return startFromDateFilteredArray.filter((e) => {
        return Date.parse(e.dateEnd) <= endDate;
    });
}

EventHandler.prototype.getByMonth = function (month){
    return this.array.filter((e) => {
        var currDate = new Date(Date.parse(e.dateStart));
        return currDate.getMonth() == Number.parseInt(month)-1;
    });
}

EventHandler.prototype.getUniqueDateAndSort = function() {
    return this.array.sort((a, b) => { 
        let itemOne = new Date(Date.parse(a.dateStart));
        let itemTwo = new Date(Date.parse(b.dateStart));
        return itemOne - itemTwo;
    }).reduce((arr, curr) => {
        if(arr.filter((s) => s.dateStart == curr.dateStart ).length == 0)
        {
            arr.push(curr);
            return arr;
        }
        return arr;
    }, []);
}

EventHandler.prototype.getSummary = function(..._) {
    (arguments.length == 0) 
    ? 
    args = this
    :
    args = Array.prototype.slice.apply(arguments);
    return args.reduce((arr, curr) => {
        if(Array.isArray(curr))
        {
            curr.filter((c) => {
                (c.dateStart == c.dateEnd) 
                ?
                arr.push(`On ${c.dateStart}: ${c.name}(${c.description})`)
                :
                arr.push(`From ${c.dateStart} to ${c.dateEnd}: ${c.name}(${c.description})`);
            });
        }
        else
        {
            (curr.dateStart == curr.dateEnd) 
            ?
            arr.push(`On ${curr.dateStart}: ${curr.name}(${curr.description})`)
            :
            arr.push(`From ${curr.dateStart} to ${curr.dateEnd}: ${curr.name}(${curr.description})`);
        }
        return arr;

    }, []);
} 

Object.setPrototypeOf(Array.prototype, EventHandler.prototype);