I'm trying to understand why MultiViewController was extended for the MVC version. The function mvcDidLoad() and the action mvcButtonPressed() are typically just included in the ViewController class. I looked through the accompanying book and some of the videos and didn't see any mention of extending the ViewController under the MVC pattern. I also didn't see that with the Recordings application. Is there some benefit, structural or clarity to this?

In "One-App-Eight-Architectures" project you have created a model directly in a view controller. I understand that for simplification you have chosen this path. But for example in MVVM the view should not know about model. I think that this can be confusing for some people. I know - it's simple example app. But from the whole point of view - this is a book about app architectures so why to violate their basic principles and dependencies and bend them over when you try to teach them?

Fix: In FolderViewController folder property is a struct, so in methods deleteItem(item:) and insert(item:) changing the folder property will trigger didSet block with tableView.reloadData().

Therefore, tableView.deleteRows(at: [IndexPath(row: index, section: 0)], with: .automatic) and self.tableView.insertRows(at: [IndexPath(row: self.folder.contents.endIndex-1, section: 0)], with: .automatic) are redundand and provoke a crash.
Deleting these lines should fix it

FolderViewController.swift 中 if let changeReason = userInfo[Item.changeReasonKey] as? String { let oldValue = userInfo[Item.newValueKey] let newValue = userInfo[Item.oldValueKey] 应改为： if let changeReason = userInfo[Item.changeReasonKey] as? String { let oldValue = userInfo[Item.newValueKey] let newValue = userInfo[Item.oldValueKey]

The problem seems to be on line 20 of FolderViewController:

viewModel.folderContents.bind(to: tableView.rx.items(dataSource: dataSource)).disposed(by: disposeBag)

I'm getting the following:

2019-05-23 12:20:09.318611-0300 Recordings[15921:6162304] Warning: Unable to create restoration in progress marker file
Assertion failed: This is a feature to warn you that there is already a delegate (or data source) set somewhere previously. The action you are trying to perform will clear that delegate (data source) and that means that some of your features that depend on that delegate (data source) being set will likely stop working.
If you are ok with this, try to set delegate (data source) to `nil` in front of this operation.
 This is the source object value: <UITableView: 0x7fa7e805c200; frame = (0 0; 375 812); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x60800005bdb0>; layer = <CALayer: 0x60000023a040>; contentOffset: {0, 0}; contentSize: {0, 0}; adjustedContentInset: {0, 0, 0, 0}>
 This is the original delegate (data source) value: <Recordings.FolderViewController: 0x7fa7e7d1a890>
Hint: Maybe delegate was already set in xib or storyboard and now it's being overwritten in code.
: file /Users/jeff/Developer/app-architecture/Recordings-MVVM-C/Pods/RxCocoa/RxCocoa/Common/DelegateProxyType.swift, line 222
2019-05-23 12:20:15.881476-0300 Recordings[15921:6162304] Assertion failed: This is a feature to warn you that there is already a delegate (or data source) set somewhere previously. The action you are trying to perform will clear that delegate (data source) and that means that some of your features that depend on that delegate (data source) being set will likely stop working.

This seems to happen in both Xcode 9.4.1 and 10.2 using RxSwift 4.0.0 and RxDataSources 3.0.2. Setting the tableView's delegate and dataSource to nil after super.viewDidLoad() fixes the issue for me.

I'm following the steps in the README to install RxSwift via Carthage, but running into complier issues. Specifically, No such module 'RxDataSources'.

The only error I get when running carthage update --platform iOS is a build failure from xcodebuild, but I'm guessing is the same issue.

Seems like everything is installed correctly.

*** Fetching RxSwift
*** Checking out RxDataSources at "3.0.2"
*** Checking out RxSwift at "4.0.0"
*** xcodebuild output can be found in /var/folders/vn/djlphdns25qcvv_53qqwcs9c000bsw/T/carthage-xcodebuild.CSrNEV.log
*** Skipped downloading RxSwift.framework binary due to the error:
	"API rate limit exceeded for 216.52.20.6. (But here's the good news: Authenticated requests get a higher rate limit. Check out the documentation for more details.)"
*** Skipped downloading RxDataSources.framework binary due to the error:
	"API rate limit exceeded for 216.52.20.6. (But here's the good news: Authenticated requests get a higher rate limit. Check out the documentation for more details.)"
*** Building scheme "RxBlocking-iOS" in Rx.xcworkspace
*** Building scheme "RxCocoa-iOS" in Rx.xcworkspace

Any ideas? Anyone else run into this? I'd love to be able to build so I can play around and better grok reactive programming.