arrays - Swift3 iOS -Firebase 如何将节点数据分离到不同的数组和字典中

Question

root
  |
  @-clothing
      |
      @-nameBrandRalphLauren//topLevel
      |  |
      |  @-apparelTops//child
      |  |    |-"garmetSweater":"white"
      |  |    |-"garmetTshirt":"blue"
      |  |    |-"postedBy":"user123"
      |  |
      |  @-apparelBottoms//child
      |       |-"garmetShorts":"tan"
      |       |-"garmetJeans":"blue"
      |       |-"postedBy":"user123"
      |
      @-nameBrandNike//topLevel
         |
         @-apparelTops//child
              |-"garmetSweater":"gray"
              |-"garmetTshirt":"pink"
              |-"postedBy":"user789"

我在 Firebase 中有几个顶级节点，它们下面还有子节点。子节点内部是键和值。我想将每个 topLevelNode (RalphLauren,Nike) 分成包含其子节点 (apparelTops, apparelBottoms) 的数组，然后将它们放入自己的数组中。

我怎样才能实现这样的目标

var nameBrandNodes = [String]()
var apparelNodes = [[String]]()
var garmetNodes = [[String:Any]]()

nameBrandNodes = [RaplhLaurn, Nike]
apparelNodes = [[apparelTops, apparelBottoms], [apparelTops, apparelBottoms]]
garmetNodes = [["postedBy":"user123"], ["garmetSweater":"white"],["garmetTshirt":"blue"],["garmetShorts":"tan"], ["garmetJeans":"blue"], ["postedBy":"user789"], ["garmetSweater":"gray"], ["garmetTshirt":"pink"]]

//**EDIT** Jay's answer is CORRECT. I forgot to add this and added it after he answered
var nameBrandArrayOfDict = [[String:[String]]]

nameBrandArrayOfDict = [[nameBrandRalphLauren:[apparelTops,apparelBottoms], [[nameBrandNike:[apparelTops,apparelBottoms]]

//this is only necessary because sometimes there won't be an apparelBottomsNode or apparelTopsNode for e.g.
nameBrandArrayOfDict = [[nameBrandRalphLauren:[apparelTops], [[nameBrandNike:[apparelBottoms]]

代码如下:

let rootRef = Database.database().reference()

var nameBrandNodes = [String]()
var apparelNodes = [[String]]()
var garmetNodes = [[String:Any]]()


let clothingRef = rootRef.child("clothing")

clothingRef?.observe(.childAdded, with: {
            (snapshot) in

       //nameBrandNodes now contains RalphLauren and Nike
       self.nameBrandNodes.append(snapshot.key)

       for nameBrand in self.nameBrandNodes{

                 let apparel = rootRef.child("clothing").child("nameBrand")
                 apparel.observeSingleEvent(of: .value, with: {
                         (snapshot) in

                         for child in snapshot.children {
                             //what should I do in here?
                         }
        }

我的最终结果是我使用了一个垂直的 tableView 和一个水平的 collectionsView。我将在 tableView 中列出 nameBrands，在 collectionView 中列出服装，在 collectionViews 单元格中列出服装项目。我知道如何将所有内容分开后放入 tableView 和 collectionView 中，我遇到的问题是将所有内容分成不同的数组。

Answer 1

我将抛​​出这个答案，因为它解决了这个问题，并可能提供一些方向和其他选项。

在此代码中，我们将填充一个 ClothingClass，其中包含与 Firebase 中的数据相匹配的数据。我们还有两个数组 bottomsArray 和 topsArray，它们将这些项目保存在单独的数组中(根据问题)。

这里的概念是 Firebase 中的一切都是快照，快照可以包含其他快照(即字典可以包含其他字典)。

我们通过 .value 读取整个节点，每个高级节点(名牌)是这些节点的键(键:值对中的键)。另一方面，该值也是一个快照，即

let apparelBottomsSnap = nameBrandSnap.childSnapshot(forPath: "apparelBottoms")

一旦我们有了这些快照，就将它们的值分配给字典，然后从那里添加 ClothingClass 以及单独的数组。 ClothingClass 和数组之间没有任何关联，除了使用该类是在此示例的代码中组织数据的另一种方式。

    class ClothingClass {
        var nameBrand = ""
        var bottomsDict = [String: Any]()
        var topsDict = [String: Any]()
    }

    var bottomsArray = [[String: Any]]()
    var topsArray = [[String: Any]]()
    var clothingArray = [ClothingClass]()

    let clothingRef = self.ref.child("clothing")
    clothingRef.observeSingleEvent(of: .value, with: { snapshot in

        for child in snapshot.children {
            let nameBrandSnap = child as! DataSnapshot //this is each name_brand
            let apparelBottomsSnap = nameBrandSnap.childSnapshot(forPath: "apparelBottoms")
            let apparelTopsSnap = nameBrandSnap.childSnapshot(forPath: "apparelTops")

            let bottomsDict = apparelBottomsSnap.value as! [String: Any]
            let topsDict = apparelTopsSnap.value as! [String: Any]

            let aClothing = ClothingClass()
            aClothing.nameBrand = nameBrandSnap.key
            aClothing.bottomsDict = bottomsDict
            aClothing.topsDict = topsDict
            clothingArray.append(aClothing)

            bottomsArray.append(bottomsDict)
            topsArray.append(topsDict)
        }

        //for testing
        for c in clothingArray {
            let n = c.nameBrand
            let b = c.bottomsDict
            let t = c.topsDict

            print("n: \(n)")
            print("  b: \(b)")
            print("  t: \(t)")
        }

        print(topsArray)
        print(bottomsArray)
    })

end end 的测试循环遍历整个数组并打印每个服装类的属性

n: name_brand_0
  b: ["garmetJeans": Blue, "garmetShorts": Pink, "postedBy": user_2]
  t: ["garmetShirt": blue, "garmetSweater": blue, "postedBy": user_0]
n: name_brand_1
  b: ["garmetJeans": Orange, "garmetShorts": Navy, "postedBy": user_3]
  t: ["garmetShirt": Green, "garmetSweater": Yellow, "postedBy": user_1]

下面的打印语句打印顶部

[
  ["garmetShirt": blue, "garmetSweater": blue, "postedBy": user_0],
  ["garmetShirt": Green, "garmetSweater": Yellow, "postedBy": user_1]
]

和底部

[
  ["garmetJeans": Blue, "garmetShorts": Pink, "postedBy": user_2],
  ["garmetJeans": Orange, "garmetShorts": Navy, "postedBy": user_3]
]