Example of an Entity with computed properties

Event

import Foundation
import RealmSwift
import ObjectMapper
import ObjectMapper_Realm

class Event: Object, Mappable, Identifiable, RandomizePlaceholder, TrackableEntity {
    dynamic var id: Int = 0
    
    fileprivate dynamic var stringType: String = ""
    fileprivate dynamic var title = ""
    fileprivate dynamic var name = ""
    dynamic var desc = ""
    dynamic var url = ""
    dynamic var eventImage = ""
    dynamic var contactEmail = ""
    dynamic var contactPhone = ""
    dynamic var twitterId = ""
    dynamic var photos = ""
    dynamic var edition = 0
    dynamic var country = ""
    dynamic var region = ""
    dynamic var city = ""
    dynamic var placesId = ""
    dynamic var venue = ""
    dynamic var address1 = ""
    dynamic var address2 = ""
    dynamic var zipCode = ""
    internal dynamic var placeHolderIndex = -1
    dynamic var interestedCount: Int = 0
    
    // MARK: Relationships
    var dates = List<EventDate>()
    var organizedBy: Member?
    
    override static func ignoredProperties() -> [String] {
        return ["eventImageURL", "detailedAddress"]
    }
    
    required convenience init?(map: Map) {
        self.init()
    }
    
    override static func primaryKey() -> String? {
        return "id"
    }
    
    func mapping(map: Map) {
        if map.mappingType == .toJSON {
            var id = self.id
            id <- map["id"]
        } else {
            id <- map["id"]
        }
        name <- map["name"]
        title <- map["title"]
        desc <- map["description"]
        url <- map["url"]
        
        stringType <- map["type"]
        eventImage <- map["hero_image.image"]
        
        contactEmail <- map["contact_email"]
        contactPhone <- map["contact_phone"]
        
        twitterId <- map["twitter_id"]
        photos <- map["photo_feed"]
        edition <- map["edition"]
        country <- map["country"]
        region <- map["region"]
        city <- map["city"]
        placesId <- map["places_id"]
        venue <- map["venue"]
        address1 <- map["address_1"]
        address2 <- map["address_2"]
        zipCode <- map["zip_code"]
        
        interestedCount <- map["members_interested_count"]
        
        dates <- (map["dates"], ListTransform<EventDate>())
        
    }

}

// MARK: Computed vars extension
extension Event {
    
    var displayName: String {
        if self.type == .summit {
            return "SingularityU \(self.name) Summit"
        }
        return self.title
    }
    
    var principalLocation: String? {
        return [city, region, country].emptyRemoved.joined(separator: ", ")
    }
    
    var detailedAddress: String {
        var address = String()
        if !self.address1.isEmpty {
            address.append(self.address1)
        }
        if !self.address2.isEmpty {
            address.append(", \(self.address2)")
        }
        if let location = self.principalLocation, !location.isEmpty {
            address.append(" - \(location)")
        }
        if !self.zipCode.isEmpty {
            address.append(" - \(self.zipCode)")
        }
        return address
    }
    
    var eventDate: String? {
        guard let first = self.dates.first,
            let last = self.dates.last,
            let firstDate = first.day?.toDate(withFormat: "yyyy-MM-dd"),
            let lastDate = last.day?.toDate(withFormat: "yyyy-MM-dd")
            else { return nil }
        
        if firstDate == lastDate {
            return firstDate.toString(withFormat: "MMM dd, yyyy")
        } else {
            if firstDate.components.year != lastDate.components.year {
                return firstDate.toString(withFormat: "MMM dd, yyyy - ") + lastDate.toString(withFormat: "MMM dd, yyyy")
            } else if firstDate.components.month != lastDate.components.month {
                return firstDate.toString(withFormat: "MMM dd - ") + lastDate.toString(withFormat: "MMM dd, yyyy")
            } else {
                return firstDate.toString(withFormat: "MMM dd - ") + lastDate.toString(withFormat: "dd, yyyy")
            }
        }
    }
    
}