Cleaning up how fetched controllers are creating, a bit more performant

guojin2020 · Oct 29, 2017 · e83d76e · e83d76e
1 parent 5768b1e
commit e83d76e
Show file tree

Hide file tree

Showing 3 changed files with 39 additions and 29 deletions.
diff --git a/DownTube/DownTube/Helpers/CoreDataController.swift b/DownTube/DownTube/Helpers/CoreDataController.swift
@@ -20,7 +20,7 @@ class CoreDataController {
         if let controller = _fetchedVideosController {
             return controller
         }
-        _fetchedVideosController = self.createControllerWithFetchRequest(Video.fetchRequest(), searchForPredicate: nil, isDownloadedPredicate: nil)
+        _fetchedVideosController = self.createControllerWithFetchRequest(Video.fetchRequest(), search: nil, isDownloaded: nil)
         return _fetchedVideosController!
     }
     private var _fetchedVideosController: NSFetchedResultsController<Video>?
@@ -30,7 +30,7 @@ class CoreDataController {
         if let controller = _fetchedStreamingVideosController {
             return controller
         }
-        _fetchedStreamingVideosController = self.createControllerWithFetchRequest(StreamingVideo.fetchRequest(), searchForPredicate: nil, isDownloadedPredicate: nil)
+        _fetchedStreamingVideosController = self.createControllerWithFetchRequest(StreamingVideo.fetchRequest(), search: nil, isDownloaded: nil)
         return _fetchedStreamingVideosController!
     }
     private var _fetchedStreamingVideosController: NSFetchedResultsController<StreamingVideo>?
@@ -39,31 +39,15 @@ class CoreDataController {
     ///
     /// - Parameter fetchRequest: request type that contains the entity
     /// - Returns: fetched results controller
-    private func createControllerWithFetchRequest<T>(_ fetchRequest: NSFetchRequest<T>, searchForPredicate: String?, isDownloadedPredicate: Bool?) -> NSFetchedResultsController<T> {
+    func createControllerWithFetchRequest<T>(_ fetchRequest: NSFetchRequest<T>, search: String?, isDownloaded: Bool?) -> NSFetchedResultsController<T> {
         // Set the batch size to a suitable number.
         fetchRequest.fetchBatchSize = 20
 
         //Sort by name
         let sortDescriptor = NSSortDescriptor(key: "title", ascending: true, selector: #selector(NSString.localizedCaseInsensitiveCompare(_:)))
 
         fetchRequest.sortDescriptors = [sortDescriptor]
-
-        var predicates: [NSPredicate] = []
-        if let search = searchForPredicate, search != "" {
-            //Searching the title
-            let predicate = NSPredicate(format: "title CONTAINS[cd] %@", search)
-            predicates.append(predicate)
-        }
-
-        if let isDownloadedPredicate = isDownloadedPredicate {
-            //Searching if item is downloaded
-            let predicate = NSPredicate(format: "isDoneDownloading == %@", NSNumber(value: isDownloadedPredicate))
-            predicates.append(predicate)
-        }
-
-        if !predicates.isEmpty {
-            fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: predicates)
-        }
+        fetchRequest.predicate = self.predicatesWithSearch(search, isDownloaded: isDownloaded)
 
         // Edit the section name key path and cache name if appropriate.
         // nil for section name key path means "no sections".
@@ -77,21 +61,47 @@ class CoreDataController {
 
         return aFetchedResultsController
     }
-    
+
     /// Creates a new fetch result controller with the search provided. If no search, returns all
     ///
     /// - Parameter search: search to use as an NSPredicate
-    func createVideosFetchedResultsControllerWithSearch(_ search: String?, isDownloadedPredicate: Bool?) -> NSFetchedResultsController<Video> {
-        return self.createControllerWithFetchRequest(Video.fetchRequest(), searchForPredicate: search, isDownloadedPredicate: isDownloadedPredicate)
+    func createVideosFetchedResultsControllerWithSearch(_ search: String?, isDownloaded: Bool?) -> NSFetchedResultsController<Video> {
+        return self.createControllerWithFetchRequest(Video.fetchRequest(), search: search, isDownloaded: isDownloaded)
     }
 
-    /// Sets a new fetch result controller with the search provided. If no search, returns all
+    private func predicatesWithSearch(_ search: String?, isDownloaded: Bool?) -> NSCompoundPredicate {
+        var predicates: [NSPredicate] = []
+        if let search = search, search != "" {
+            //Searching the title
+            let predicate = NSPredicate(format: "title CONTAINS[cd] %@", search)
+            predicates.append(predicate)
+        }
+
+        if let isDownloadedPredicate = isDownloaded {
+            //Searching if item is downloaded
+            let predicate = NSPredicate(format: "isDoneDownloading == %@", NSNumber(value: isDownloadedPredicate))
+            predicates.append(predicate)
+        }
+
+        return NSCompoundPredicate(andPredicateWithSubpredicates: predicates) //Doesn't matter if empty
+    }
+
+    /// Sets the predicate for the fetched videos controller and performs the fetch
     ///
-    /// - Parameter search: search to use as an NSPredicate
-    func setVideosFetchedResultsControllerWithSearch(_ search: String?, isDownloadedPredicate: Bool?) {
-        _fetchedVideosController = self.createVideosFetchedResultsControllerWithSearch(search, isDownloadedPredicate: isDownloadedPredicate)
+    /// - Parameters:
+    ///   - search: search, optional
+    ///   - isDownloaded: if true, only looks for downloaded video
+    func setSearchForDownloadedVideos(_ search: String?, isDownloaded: Bool?) {
+        self.fetchedVideosController.fetchRequest.predicate = self.predicatesWithSearch(search, isDownloaded: isDownloaded)
+
+        do {
+            try self.fetchedVideosController.performFetch()
+        } catch let error {
+            print("Could not search for videos: \(error)")
+        }
     }
 
+
     //Rest of the core data stack
 
     lazy var applicationDocumentsDirectory: URL = {

diff --git a/DownTube/DownTube/Helpers/VideoManager.swift b/DownTube/DownTube/Helpers/VideoManager.swift
@@ -308,7 +308,7 @@ class VideoManager: NSObject, DownloadManagerDelegate {
 
     /// Checks if any video files don't exist and need to be downloaded
     func checkIfAnyVideosNeedToBeDownloaded() {
-        guard let needToDownload = CoreDataController.sharedController.createVideosFetchedResultsControllerWithSearch(nil, isDownloadedPredicate: false).fetchedObjects, !needToDownload.isEmpty else {
+        guard let needToDownload = CoreDataController.sharedController.createVideosFetchedResultsControllerWithSearch(nil, isDownloaded: false).fetchedObjects, !needToDownload.isEmpty else {
             return
         }
         var indexesToReload: [Int] = []

diff --git a/DownTube/DownTube/View Controllers/MasterViewController.swift b/DownTube/DownTube/View Controllers/MasterViewController.swift
@@ -657,7 +657,7 @@ extension MasterViewController: UISearchResultsUpdating {
         guard let search = searchController.searchBar.text else { return }
 
         print("Updating search results, search is \"\(search)\"")
-        CoreDataController.sharedController.setVideosFetchedResultsControllerWithSearch(search, isDownloadedPredicate: nil)
+        CoreDataController.sharedController.setSearchForDownloadedVideos(search, isDownloaded: nil)
         self.tableView.reloadData()
     }
 }