ios - MVVM and RxSwift for Search Screen -

in purpose of education mvvm , rxswift want build simple search screen, have table view , search bar. when user types search bar show have in table. sounds pretty simple, can't find tutorial suits me.

i have written code in view controller, can't understand have observe search text changes , call database method, filter items search text.

some code, have.

my viewcontroller

import foundation import uikit import rxswift import rxcocoa  class placesearchviewcontroller: uiviewcontroller {      //mark: -       @iboutlet weak var searchbar: uisearchbar!     @iboutlet weak var tableview: uitableview!      //mark: - dependencies      private var viewmodel: placesearchviewmodel!     private let disposebag = disposebag()      //mark: - lifecycle      override func viewdidload() {         super.viewdidload()          viewmodel = placesearchviewmodel()         addbindstoviewmodel(viewmodel)     }      //mark: - rx      private func addbindstoviewmodel(viewmodel: placesearchviewmodel) {          searchbar.rx_text.bindto(viewmodel.searchtextobservable)          viewmodel.placesobservable.bindto(tableview.rx_itemswithcellfactory) {             (tableview: uitableview, index, place: place) in              let indexpath = nsindexpath(foritem: index, insection: 0)             let cell = tableview.dequeuereusablecellwithidentifier("cell", forindexpath: indexpath) placecell              cell.configurewithobject(place)              return cell              }             .adddisposableto(disposebag)          tableview.rx_contentoffset             .subscribe { _ in                 if self.searchbar.isfirstresponder() {                     _ = self.searchbar.resignfirstresponder()                 }             }             .adddisposableto(disposebag)     } } 

and view model:

import foundation import rxswift import rxcocoa  class placesearchviewmodel {      //mark: - dependecies     private let disposebag = disposebag()      //mark: - model      private let placesobservable: observable<[place]>     var searchtextobservable = variable<string>("")      //mark: - set      init() {          placesobservable = searchtextobservable.asobservable()             //wait 0.3 s after last value fire new value             .debounce(0.3, scheduler: mainscheduler.instance)             //only fire if value different last 1             .distinctuntilchanged()             //convert observable<string> observable<[place]>             .flatmaplatest { searchstring -> observable<[place]> in                  // code here can't write.              }             //make sure subscribers use same exact subscription             .sharereplay(1)     }  } 

also, have method [database searchplaces:searchtext] returns array of places - [place]. can't understand , how place in flatmaplatest of viewmodel.

i create reactive wrapper database creating observable<[place]>.

this code

placesobservable = searchtextobservable.asobservable()             //wait 0.3 s after last value fire new value             .debounce(0.0, scheduler: mainscheduler.instance)             //only fire if value different last 1             .distinctuntilchanged()             //convert observable<string> observable<weather>             .flatmaplatest { searchstring -> observable<[anyobject]> in                 return tpreactivedatabase.sharedinstance.searchplacesbytitle(searchstring)             }             //make sure subscribers use same exact subscription             .sharereplay(1) 

and wrapper method searchplacesbytitle

class tpreactivedatabase: nsobject {      static let sharedinstance = tpreactivedatabase()      // mark: - reactive place database      func searchplacesbytitle(title: string) -> observable<[anyobject]> {         return observable.create { observer in              var places = [anyobject]()              if (title.characters.count > 0) {                 places = dbaccesskit.searchplacesbytitle(title)             }              observer.on(.next(places))             observer.on(.completed)              return anonymousdisposable {              }         }     } }