如何检查解析的rss变量是否包含swift 2中的确切元素

Question

I have a rss link which I parse it using SWXMLHash and then I use it's elements like below but when an element is missing in the rss I get below error message! how can I check if rss contain for example source element if it doesn't contain it put " " in the variable !

code :

UPDATE : Fixed Code :

let count = xml["rss"]["channel"]["item"].all.count

    var Name = ""
    var Image = ""
    var Link = ""

    for var index = 0; index < count; index++ {
        Name = xml["rss"]["channel"]["item"][index]["title"].element!.text!
        if let element = xml["rss"]["channel"]["item"][index]["source"].element?.attributes["url"] as String? {
            Image = element
            Link = element
        } else {
            print("Blank")
            Image = ""
            Link = ""
        }

        let ap = pic(name: Name ,img : Image, link : Link)
        self.tableData.append(ap)

        //for reducing delay of loading table view data
        dispatch_async(dispatch_get_main_queue(), {
        self.tableView.reloadData()
        return
        })
    }

Answer 1

you should check for optional where you have force unwrap element, if it has element take value else put ""

let count = xml["rss"]["channel"]["item"].all.count

let arrSource:NSMutableArray = []

for var index = 0; index < count; index++ {
    if let element = xml["rss"]["channel"]["item"][index]["source"].element?.attributes["url"] as String? {
        print("Element \(element)")
        arrSource.addObject(element)
    } else {
       print("Blank")
    }
}
print("Count \(arrSource.count) Arr \(arrSource)")

This works when source or url is empty and prints Blank if one of them are empty