在其中找到nil时如何处理JSON

Question

Recently I am dealing with JSON and everyday I encounter new problem, although I like it because I am learning everyday. StackOverflow mates are helping me tremendously, thank you for that.

My app was running fine , until I found nil in some JSON return. Here is my JSON return

{
"main_content" : [
{
  "author" : "maruf khandakar",
  "post_id" : 110,
  "post_date" : "October 3, 2016",
  "title" : "hjhjhjhjkljkhasfreiwutb cltjutjuregjre nb",
  "show_comment_number" : "0",
  "show_likes" : "0",
  "post_img" : [
    {
      "guid" : "http:\/\/xxx\/wp-content\/uploads\/2016\/10\/IMG_1475492476.jpg"
    }
  ],
  "author_img" : "http:\/\/xxx\/wp-content\/uploads\/2016\/10\/Screenshot_1-2.png",
  "post_time" : "11:01 am",
  "blog_text" : "sfdhjusolidasfjgfkdsjfdklshfj"
},

{
  "author" : "maruf khandakar",
  "post_id" : 149,
  "post_date" : "November 17, 2016",
  "title" : "Test",
  "show_comment_number" : "0",
  "show_likes" : "0",
  "post_img" : [

  ],
  "author_img" : "http:\/\/xxx\/wp-content\/uploads\/2016\/10\/Screenshot_1-2.png",
  "post_time" : "4:03 am",
  "blog_text" : "Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip"
     }
   ]
 }

Here in the 2nd chunk of JSON return you can see there is no guid inside ** post_img** . So whenever my array iterate through this, it crashes. Here is my model class I declared earlier

import Foundation
import SwiftyJSON

class HomeFeedJSON {

    var title: String?
    var author_img: URL?
    var author: String?
    var blog_text: String?
    var post_img: URL?
    var likesNumber: Int?
    var commentNumber:Int?

    init(items: JSON){
      self.author = items["author"].stringValue
      self.author_img = items["author_img"].URL
      self.title = items["title"].stringValue
      self.blog_text = items["blog_text"].stringValue
      let post_imgAA = items["post_img"].array
      for itemsIMG in post_imgAA! {
         self.post_img = itemsIMG["guid"].URL
      }
      self.likesNumber = items["show_likes"].intValue
      self.commentNumber = items["show_comment_number"].intValue
   }

}

Later I tried to do some filtering like this

class HomeFeedJSON {

var title: String?
var author_img: URL?
var author: String?
var blog_text: String?
var post_img: URL?
var likesNumber: Int?
var commentNumber:Int?

init(items: JSON){
  //self.author = items["author"].stringValue

  if let userUrl = items["author"].string {
        self.author = userUrl
    }
  if let authorImgUrl = items["author_img"].URL {
       self.author_img = authorImgUrl
    }
  if let titleUrl = items["title"].string {
        self.title = titleUrl
    }
  if let blogTextURL = items["blog_text"].string {
      self.blog_text = blogTextURL
    }

  if let post_imgAA = items["post_img"].array {
  for itemsIMG in post_imgAA {
    if let postUrl = itemsIMG["guid"].URL {
        self.post_img = postUrl
    } else {
        let myURL = "www.thewoodjoynt.com/Content/Images/Products/NoImageAvailable.jpg"
        let noImage: URL = URL(string: myURL)!
        self.post_img = noImage
    }
    }
  }

  self.likesNumber = items["show_likes"].intValue
  self.commentNumber = items["show_comment_number"].intValue
  }

}

Still it crashes because I am sure my filtering was not good enough. Please give me some suggestion , how to filter these nil JSON return. Thank You in advance.

Answer 1

Solved the issue like this

class HomeFeedJSON {

var _title: String?
var _author_img: URL?
var _author: String?
var _blog_text: String?
var _post_img: URL?
var _likesNumber: Int?
var _commentNumber:Int?

init(items: JSON){
    self._author = items["author"].stringValue
    self._author_img = items["author_img"].URL
    self._title = items["title"].stringValue
    self._blog_text = items["blog_text"].stringValue
    let post_imgAA = items["post_img"].array
    for itemsIMG in post_imgAA! {
        self._post_img = itemsIMG["guid"].URL
    }
    self._likesNumber = items["show_likes"].intValue
    self._commentNumber = items["show_comment_number"].intValue
}

var title: String {
    if _title == nil {
        _title = ""
    }
    return _title!
}
var author_img: URL {
    if _author_img == nil {
        let myURL = "http://thewoodjoynt.com/Content/Images/Products/NoImageAvailable.jpg"
        let noImage: URL = URL(string: myURL)!
        _author_img = noImage
    }
    return _author_img!
}

var author: String {
    if _author == nil {
        _author = ""
    }
    return _author!
}

var blog_text: String {
    if _blog_text == nil {
        _blog_text = ""
    }
    return _blog_text!
}

var post_img: URL {
    if _post_img == nil {
        let myURL = "http://thewoodjoynt.com/Content/Images/Products/NoImageAvailable.jpg"
        let noImage: URL = URL(string: myURL)!
        _post_img = noImage
    }
    return _post_img!
}

var likesNumber: Int {
    if _likesNumber == nil {
        _likesNumber = 0
    }
    return _likesNumber!
}

var commentNumber: Int {
    if _commentNumber == nil {
        _commentNumber = 0
    }
    return _commentNumber!
}

}