Merge pull request #1 from priteshrnandgaonkar/imporvements

Imporvements

Author: priteshrnandgaonkar

Example/KVStoreExample/KVStoreExample/ViewController.swift

@@ -16,7 +16,7 @@ class ViewController: UIViewController {
     @IBOutlet weak var fetchTextField: UITextField!
     @IBOutlet weak var deleteTextField: UITextField!
 
-    var storeManager: KVStoreManager!
+    var storeManager: KVStoreManager<String>!
 
     override func viewDidLoad() {
         super.viewDidLoad()
@@ -44,6 +44,7 @@ class ViewController: UIViewController {
         }
 
         do {
+            
          try storeManager.insert(value: valueUnwrapped.data(using: String.Encoding.utf8)!, for: keyUnwrapped)
         showAlert(withTitle: "Success", buttonTitle: "OK", message: "Successfully added key value pair in database", okAction: nil)
 
@@ -61,28 +62,18 @@ class ViewController: UIViewController {
             return
         }
 
-        do {
-            let data = try storeManager.getValue(for: keyUnwrapped)
-            guard let fetchedString = String(data: data, encoding: .utf8) else {
-              showAlert(withTitle: "Error", buttonTitle: "OK", message: "Failed to convert blob to string", okAction: nil)
-                return
-            }
-            
-            showAlert(withTitle: "Success", buttonTitle: "OK", message: "Successfully Fetched Value. Your Key: \(keyUnwrapped), Value: \(fetchedString)", okAction: nil)
-            
-        } catch (let error) {
-            var errorMessage = error.localizedDescription
-            if let sqliteError = error as? SQLiteError {
-                errorMessage = sqliteError.description
-            }
-            showAlert(withTitle: "Error", buttonTitle: "OK", message: errorMessage, okAction: nil)
-            
+        let data = storeManager[keyUnwrapped] //storeManager.getValue(for: keyUnwrapped)
+        guard let unwrappedData = data, let fetchedString = String(data: unwrappedData, encoding: .utf8) else {
+            showAlert(withTitle: "Error", buttonTitle: "OK", message: "Failed to get value for \(keyUnwrapped)", okAction: nil)
+            return
         }
+        
+        showAlert(withTitle: "Success", buttonTitle: "OK", message: "Successfully Fetched Value. Your Key: \(keyUnwrapped), Value: \(fetchedString)", okAction: nil)
+        
     }
 
     @IBAction func tappedDelete(_ sender: UIButton) {
         let key = deleteTextField.text
-        
         guard let keyUnwrapped = key, keyUnwrapped.characters.count > 0 else {
             showAlert(withTitle: "Error", buttonTitle: "OK", message: "Key is empty. Key should have atleast one character", okAction: nil)
             return

KVStore/KVStoreManager.swift

@@ -12,14 +12,14 @@ protocol CRUDDelegate {
     func insert<T: Hashable>(value: Data, for key: T) throws
     func deleteValue<T: Hashable>(for key: T) throws
     func update<T: Hashable>(value: Data, for key: T) throws
-    func getValue<T: Hashable>(for key: T) throws -> Data
+    func getValue<T: Hashable>(for key: T) -> Data?
 }
 
-public class KVStoreManager: CRUDDelegate {
+public final class KVStoreManager<F: Hashable>: CRUDDelegate {
 
     let db: SQLiteDatabase
 
-    /// This init method would create the db file with name passed as parameter and would open the database connection. And if the file already exist it will just open the database connection.Also it would create a table in these file if its not already created.All this operations are done synchronously in background thread.
+    /// This init method would create the db file with name passed as parameter and would open the database connection. And if the file already exist it will just open the database connection.Also it would create a table in these file if its not already created.Sqlite is configured in serialised mode
     ///
     /// - parameter fileName: The sqlite filename.     
     ///
@@ -34,7 +34,7 @@ public class KVStoreManager: CRUDDelegate {
         print("Successfully opened connection to database.")
     }
 
-    /// Inserts or Updates the key value pair in the database in an synchronus thread safe way in background thread
+    /// Inserts or Updates the key value pair in the database in a syrialized way
     ///
     /// - parameter value: Its of type Data. This is stored as BLOB in sqlite for the unique key.
     /// - parameter key: Its a unique key which is of type `Hashable` and its also a primary key in a database
@@ -46,7 +46,7 @@ public class KVStoreManager: CRUDDelegate {
 
     }
 
-    /// Deletes the key value pair in the database in synchronus thread safe way in background thread
+    /// Deletes the key value pair in the database in a syrialized way
     ///
     /// - parameter value: Its of type Data. This is stored as BLOB in sqlite for the unique key.
     /// - parameter key: Its a unique key which is of type `Hashable` and its also a primary key in a database
@@ -56,7 +56,7 @@ public class KVStoreManager: CRUDDelegate {
         try db.delete(key: key.hashValue)
     }
 
-    /// Updates the key value pair in the database in synchronus way in background thread
+    /// Updates the key value pair in the database in a syrialized way
     ///
     /// - parameter key: Its a unique key which is of type `Hashable` and its also a primary key in a database
     ///
@@ -65,12 +65,25 @@ public class KVStoreManager: CRUDDelegate {
         try db.update(model:  RowModel(id: (key.hashValue) , data: value))
     }
 
-    /// Fetches the value for a key in synchronus way in background thread
+    /// Fetches the value for a key in a syrialized way
     ///
     /// - parameter key: Its a unique key which is of type `Hashable` and its also a primary key in a database
     ///
     /// - returns: Data
-    public func getValue<T: Hashable>(for key: T) throws -> Data {
-        return try db.getValue(for: key.hashValue, tableName: RowModel.tableName)
+    public func getValue<T: Hashable>(for key: T) -> Data? {
+        do {
+            let data = try db.getValue(for: key.hashValue, tableName: RowModel.tableName)
+            return data
+        }
+        catch {
+            return nil;
+        }
+    }
+    
+    /// returns Data? for get query. You cannot set values through subscript
+    public subscript(index: F) -> Data? {
+        get {
+            return getValue(for: index)
+        }
     }
 }