swift 2如何在解析的xml变量中使用正则表达式获取时间模式

Question

I have a rss feed which I parse it's data using SWXMLHash, there are three type of data which I need from this feeds,Image src , title , time.

I don't have any problem with getting images and title but there is a bit problem in getting time value.

my rss feed time formate is like :

<item>
          <title>item subject</title>
          <description>
          <img align="right" hspace="5" src="http://test.org/index/uploads/conductor/thumbnails/0192.jpg"/>
          </description>
          <pubDate>2015-11-14 05:05:03</pubDate>
  </item>

problem is that pubDate tag contains date + time , but I need just the time. is there a way to find xxxx-xx-xx pattern and replace it with '' Or find xx:xx:xx which is time?

this is how I parse my rss feed :

struct sprog {
        var spTitle : String!
        var spImg : String!
        var spTime : String!
    }

var tableData = [sprog]()


override func viewDidLoad() {
    super.viewDidLoad()

    let url = NSURL(string: "http://razavitv.aqr.ir/index/conductor_module/rss")
    let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {(data, response, error) in      
        let dataString = NSString(data: data!, encoding: NSUTF8StringEncoding) as! String
        let processedString = (dataString as NSString).stringByReplacingOccurrencesOfString("<![CDATA[", withString: "").stringByReplacingOccurrencesOfString("]]>", withString: "") as String


        let data: NSData = processedString.dataUsingEncoding(NSUTF8StringEncoding)!
        let xml = SWXMLHash.parse(data)

        //one root element
        let count = xml["rss"]["channel"]["item"].all.count

        for var i = 0; i < count; i++ {
            let appName = xml["rss"]["channel"]["item"][i]["title"].element!.text!
            let appUrl = xml["rss"]["channel"]["item"][i]["description"]["img"].element!.attributes["src"]
            let appTime = xml["rss"]["channel"]["item"][i]["pubDate"].element!.text!


            let ap = sprog(spTitle: appName , spImg : appUrl , spTime : appTime)
            self.tableData.append(ap)

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

        }

    }

    task.resume()

}

Answer 1

Don't use regex to turn a string into a date — date/time formatting and calculation is a much hairier problem than it ever appears. What time zone are you dealing with? What time zone is the user in? Is it a leap year? Is the date you're reading valid, even if it is/isn't a leap year? And that's all assuming you're dealing with a fixed format coming from the RSS feed... it gets even more fun when you're dealing with date strings that could come out of end-user-configured software.

Instead of trying to tackle that yourself, let the system do it for you. Use a date formatter to read the date (see "Parsing Fixed Format Date Representations" on that page for an example. Then, if you don't need parts of the date (like the day/month/year), create an NSDateComponents object from the date and read from it only the fields (hour/minute/etc) you're interested in.

Answer 2

Why Don't you use split ? your can split your variable and store time and date in different variables :

//seperate string by space
                var apptime_array = appTime.componentsSeparatedByString(" ")
                //seperate string by :
                apptime_array = apptime_array[1].componentsSeparatedByString(":")
                appTime = "\(apptime_array[0]):\(apptime_array[1])"