Part5

Author: jquave

SwiftTutorial.xcodeproj/project.pbxproj

@@ -13,6 +13,7 @@
 		020BE45719A71EB3006C3E0B /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 020BE45619A71EB3006C3E0B /* Images.xcassets */; };
 		020BE46319A71EB3006C3E0B /* SwiftTutorialTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 020BE46219A71EB3006C3E0B /* SwiftTutorialTests.swift */; };
 		020BE46D19A721FF006C3E0B /* APIController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 020BE46C19A721FF006C3E0B /* APIController.swift */; };
+		020BE46F19A7265F006C3E0B /* Blank52.png in Resources */ = {isa = PBXBuildFile; fileRef = 020BE46E19A7265F006C3E0B /* Blank52.png */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -36,6 +37,7 @@
 		020BE46119A71EB3006C3E0B /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		020BE46219A71EB3006C3E0B /* SwiftTutorialTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SwiftTutorialTests.swift; sourceTree = "<group>"; };
 		020BE46C19A721FF006C3E0B /* APIController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = APIController.swift; sourceTree = "<group>"; };
+		020BE46E19A7265F006C3E0B /* Blank52.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = Blank52.png; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -77,6 +79,7 @@
 		020BE44C19A71EB3006C3E0B /* SwiftTutorial */ = {
 			isa = PBXGroup;
 			children = (
+				020BE46E19A7265F006C3E0B /* Blank52.png */,
 				020BE46C19A721FF006C3E0B /* APIController.swift */,
 				020BE44F19A71EB3006C3E0B /* AppDelegate.swift */,
 				020BE45119A71EB3006C3E0B /* SearchResultsViewController.swift */,
@@ -192,6 +195,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				020BE46F19A7265F006C3E0B /* Blank52.png in Resources */,
 				020BE45519A71EB3006C3E0B /* Main.storyboard in Resources */,
 				020BE45719A71EB3006C3E0B /* Images.xcassets in Resources */,
 			);

SwiftTutorial/Blank52.png

@@ -15,6 +15,7 @@ class SearchResultsViewController: UIViewController, UITableViewDataSource, UITa
     @IBOutlet var appsTableView : UITableView?
     var tableData = []
     var api = APIController()
+    var imageCache = [String : UIImage]()
 
     override func viewDidLoad() {
         super.viewDidLoad()
@@ -28,23 +29,59 @@ class SearchResultsViewController: UIViewController, UITableViewDataSource, UITa
     }
 
     func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
+        
         let cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(kCellIdentifier) as UITableViewCell
 
-        let rowData: NSDictionary = self.tableData[indexPath.row] as NSDictionary
+        var rowData: NSDictionary = self.tableData[indexPath.row] as NSDictionary
 
-        cell.textLabel.text = rowData["trackName"] as String
+        // Add a check to make sure this exists
+        let cellText: String? = rowData["trackName"] as? String
+        cell.textLabel.text = cellText
+        cell.imageView.image = UIImage(named: "Blank52")
 
-        // Grab the artworkUrl60 key to get an image URL for the app's thumbnail
-        let urlString: NSString = rowData["artworkUrl60"] as NSString
-        let imgURL: NSURL = NSURL(string: urlString)
-        
-        // Download an NSData representation of the image at the URL
-        let imgData: NSData = NSData(contentsOfURL: imgURL)
-        cell.imageView.image = UIImage(data: imgData)
 
         // Get the formatted price string for display in the subtitle
         let formattedPrice: NSString = rowData["formattedPrice"] as NSString
 
+        // Jump in to a background thread to get the image for this item
+        
+        // Grab the artworkUrl60 key to get an image URL for the app's thumbnail
+        let urlString = rowData["artworkUrl60"] as String
+        
+        // Check our image cache for the existing key. This is just a dictionary of UIImages
+        var image = self.imageCache[urlString]
+        
+        
+        if( image == nil ) {
+            // If the image does not exist, we need to download it
+            var imgURL: NSURL = NSURL(string: urlString)
+            
+            // Download an NSData representation of the image at the URL
+            let request: NSURLRequest = NSURLRequest(URL: imgURL)
+            NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {(response: NSURLResponse!,data: NSData!,error: NSError!) -> Void in
+                if error == nil {
+                    image = UIImage(data: data)
+                    
+                    // Store the image in to our cache
+                    self.imageCache[urlString] = image
+                    if let cellToUpdate = tableView.cellForRowAtIndexPath(indexPath) {
+                        cellToUpdate.imageView.image = image
+                    }
+                }
+                else {
+                    println("Error: \(error.localizedDescription)")
+                }
+            })
+            
+        }
+        else {
+            dispatch_async(dispatch_get_main_queue(), {
+                if let cellToUpdate = tableView.cellForRowAtIndexPath(indexPath) {
+                    cellToUpdate.imageView.image = image
+                }
+            })
+        }
+        
         cell.detailTextLabel.text = formattedPrice
 
         return cell