【发布时间】：2017-05-05 12:50:42
【问题描述】：
我目前正在开展一个让用户租用额外空间的项目。你可以认为airbnb的克隆。在这个 iOS 应用中，我将 Firebase 用于后端即服务。
我想检索满足过滤选项的公寓，例如床位数、卧室数量、吸烟等。从逻辑上讲，我首先按时间段对所有公寓进行分组，然后获取满足过滤城市的公寓，然后我就是获取满足过滤器的单位。然后我将一一迭代所有公寓以获取它们的图像。
我的 Json 树是这样的：
filter_flats/FlatCity/FlatID
time_slots/timestamp/flatID:true
flat_images/FlatID
这是我正在尝试的：
import Foundation
import Firebase
import FirebaseStorage
protocol QuerymasterDelegate :class
{
func getFilteredFlats(filter:FilterModel, completion: @escaping ([FilteredFlat]) -> ())
}
class Querymaster:QuerymasterDelegate
{
var flatEndpoint = FIRFlat()
var returningFlats = [FilteredFlat]()
/////////////////////////////////////////////////////////////
//MARK: This method pulls all flats with required timeslot.//
/////////////////////////////////////////////////////////////
internal func getFilteredFlats(filter: FilterModel, completion: @escaping ([FilteredFlat]) -> ()) {
var zamanAraliginaUygunFlatlar = [String]()
FIRREF.instance().getRef().child("time_slots").queryOrderedByKey().queryStarting(atValue: filter.fromDate?.toTimeStamp()).queryEnding(atValue: filter.toDate?.toTimeStamp()).observeSingleEvent(of: .value, with: { (ss) in
for ts in ss.children.allObjects
{
let timeslotFlatObj = ts as! FIRDataSnapshot
let timeslotForFlat = timeslotFlatObj.value as! [String:Bool]
for x in timeslotForFlat
{
if (x.value == true && !zamanAraliginaUygunFlatlar.contains(x.key))
{
zamanAraliginaUygunFlatlar.append(x.key)
}
}
}
/////////////////////////////////////////////////////////
//MARK: This method pulls all flats with filtered city.//
/////////////////////////////////////////////////////////
FIRREF.instance().getRef().child("filter_flats/" + filter.city!).observe(.value, with: { (ss) in
var sehirdekiFlatler = [String:Flat]()
for i in ss.children.allObjects
{
let flt = Flat()
let flatObject = i as! FIRDataSnapshot
let mainDict = flatObject.value as! [String:Any]
flt.userID = (mainDict["userId"] as? String)!
flt.id = flatObject.key
flt.city = filter.city
flt.title = mainDict["title"] as? String
flt.bathroomCount = mainDict["bathroomCount"] as? Int
flt.bedCount = mainDict["bedCount"] as? Int
flt.bedroomCount = mainDict["bedroomCount"] as? Int
flt.internet = mainDict["internet"] as? Bool
flt.elevator = mainDict["elevator"] as? Bool
flt.heating = mainDict["heating"] as? Bool
flt.gateKeeper = mainDict["gateKeeper"] as?Bool
flt.parking = mainDict["parking"] as? Bool
flt.pool = mainDict["pool"] as? Bool
flt.smoking = mainDict["smoking"] as? Bool
flt.tv = mainDict["tv"] as? Bool
flt.flatCapacity = mainDict["capacity"] as? Int
flt.cooling = mainDict["cooling"] as? Bool
flt.price = mainDict["price"] as? Double
flt.washingMachine = mainDict["washingMachine"] as? Bool
sehirdekiFlatler[flt.id] = flt
if(!(zamanAraliginaUygunFlatlar).contains(flt.id))
{
if(filter.bathroomCount == nil || filter.bathroomCount! <= flt.bathroomCount!)
{
if(filter.bedCount == nil || filter.bedCount! <= flt.bedCount!)
{
if(filter.bedroomCount == nil || filter.bedroomCount! <= flt.bedroomCount!)
{
if(filter.internet == false || filter.internet! == flt.internet!)
{
if(filter.elevator == false || filter.elevator! == flt.elevator!)
{
if(filter.heating == false || filter.heating! == flt.heating!)
{
if(filter.gateKeeper == false || filter.gateKeeper! == flt.gateKeeper!)
{
if(filter.parking == false || filter.parking! == flt.parking!)
{
if(filter.pool == false || filter.pool! == flt.pool!)
{
if(filter.smoking! == false || filter.smoking! == flt.smoking!)
{
if(filter.tv! == false || filter.tv! == flt.tv!)
{
if(filter.capacity == nil || filter.capacity! <= flt.flatCapacity!)
{
if(filter.cooling == false || filter.cooling! == flt.cooling!)
{
if(filter.priceFrom == nil || filter.priceFrom! <= flt.price!)
{
if(filter.priceTo == nil || filter.priceTo! >= flt.price!)
{
if(filter.washingMachine == false || filter.washingMachine! == flt.washingMachine!)
{
let filteredFlat = FilteredFlat()
filteredFlat.flatCity = flt.city
filteredFlat.flatID = flt.id
filteredFlat.flatPrice = flt.price
filteredFlat.flatTitle = flt.title
filteredFlat.userID = flt.userID
self.returningFlats.append(filteredFlat)
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
////////////////////////////////////////////////////////////////
//MARK: This method pulls thumbnail image for returning Flats.//
////////////////////////////////////////////////////////////////
if self.returningFlats.count > 0
{
for a in self.returningFlats
{
FIRREF.instance().getRef().child("flat_images/" + a.flatID!).observeSingleEvent(of: .value, with: { (ss) in
let dict = ss.children.allObjects[0] as! FIRDataSnapshot
let obj = dict.value as! [String:String]
let flatImageDownloaded = FlatImageDownloaded(imageID: dict.key, imageDownloadURL: obj["downloadURL"]!)
a.flatThumbnailImage = flatImageDownloaded
completion(self.returningFlats)
})
}
}
})
})
}
}
标记代码This method pulls thumbnail image for returning Flats. 通常会因为在单位节点之间跳转而导致获取数据较慢。
我没有意识到我做错了什么。你能推荐更有效的方法吗？
提前致谢。
【问题讨论】：
-
从 Firebase 数据库下载数据通常只是您可用带宽和正在下载的数据量的简单问题。延迟通常不是问题，因为Firebase pipelines requests where possible。您在多大的带宽上下载了多少数据，需要多少时间？可以reproduce with a simpler piece of code and share the JSON (as text)吗？
标签： ios swift firebase firebase-realtime-database nosql