objective c - ReactiveCocoa MVVM with UITableView -

I am using reactive cocoa and am trying to implement MVVM. There is a typical typical UITableView scenario with fresh controls to reload my data.

I left UITableDataSource / Delegate methods because they are straight forward. The code given below shows how I designed the viewold and view controller to fit together.

ViewModel.h

  @property (get strong, nonatomic, read-only) RAC COMMAND * getItemsCommand; @ Property (strong, non-monetary, read-only) NSArray * items;   
  ViewModel.m   
  - (instancetype) init {self = [super init]; If (! Self!) Return zero; @weakify (self); Self.getItemsCommand = [[RAC Common Alloc] initWithSignalBlock: ^ RACSignal * (id input) {return [[items get datasource) doNext: ^ (NSArray * item) {@ Strongx (self); // I actually do a little extra work like // sorting properly for the scene. Self. Item = item; }]; }]; Self return; }   
  ViewController.m   
  - (zero) viewDidoadload {[Super Viewedload]; [self.tableView addSubview: self.refreshControl]; RACsignal * Refresh Signals = [RACSingle Merge: @ [[Self refresh control rac_signalForControlEvents: UIControlEventValueChanged], [RACSingle Returns: Zero]]]; [RefreshScienceSubscribe: Next: ^ (id x) {[self.viewModel.getItemsCommand executed: zero]; }]; [RACObserve (self.viewModel, item) subscribeNext: ^ (NSArray * item) {[self.tableViewReloadData]; } Completed: ^ {[Self. Refresh Controller End Refreshing]; }]; }   
  Question / Problem   
 
 Block  complete  where I call  EndRefreshing  is never executed and I do not understand for my life.  
 Would it be better to use a public method  - (RACSignal *) getItems  getItems  instead of RAC?  
 Is my use correct in scene modals (i.e. to order the array of items) to apply side effects in doNext:  without any additional subscription?    
 
 
 1) Well, we see the signal:  
  RACObserve (self.viewModel, items)   
 When will it be complete? Only when  self.viewModel  or  itself  is distributed like any other  RACObserve  until those objects are all around  next  does not set  self.items  at any time.  
 It seems that you want it to end to  endRefreshing  once  getItemsCommand , and you have such implicit expectations That's because you know that this order set will be  self.viewModel.items , it will be full of any kind - but it is not. To see that when the command is complete, you will have to subscribe to the returned signal of the command.  
 2) The advantage of  RACCommand  is automatically enable / disable behavior, which you are not actually taking advantage of here, the more statutory thing will be that  self .refreshControl.rac_command = self.viewModel.getItemsCommand; . They will handle  end refreshing  stuff for you, saving you headache from Part 1.  
 3) ... type of code  *  injects the family of the  signals in every member of the sign  so if you sign a signal Subscribes twice, and it sends a next, any  doNext  block, it will be applied twice, a clear membership is more clear, since you want to execute it once next time No matter how many times it is subscribed.  
  @weakify (self); Self.getItemsCommand = [[RAC Common Alloc] initWithSignalBlock: ^ RACSignal * (id input) {RACSignal * itemsSignal = [ItemsDataSource getItems]; [Communications subscribe next: ^ (NSERRE * item) {@ Strongx (self); // content ... self Item = item; }]; Return items}];