Merge pull request magicalpanda#238 from blackgold9/BadModelCleanup

Bad model cleanup

Categories/NSPersistentStoreCoordinator+MagicalRecord.m

@@ -70,12 +70,30 @@ - (NSPersistentStore *) MR_addSqliteStoreNamed:(id)storeFileName withOptions:(__
     [self MR_createPathToStoreFileIfNeccessary:url];
 
     NSPersistentStore *store = [self addPersistentStoreWithType:NSSQLiteStoreType
-                                                 configuration:nil
-                                                           URL:url
-                                                       options:options
-                                                         error:&error];
-    if (!store) 
+                                                  configuration:nil
+                                                            URL:url
+                                                        options:options
+                                                          error:&error];
+
+    if (!store && [MagicalRecord shouldDeleteStoreOnModelMismatch])
     {
+        if ([error.domain isEqualToString:NSCocoaErrorDomain] &&
+            [error code] == NSMigrationMissingSourceModelError) {
+            // Could not open the database, so... kill it!
+            [[NSFileManager defaultManager] removeItemAtURL:url error:nil];
+
+            // Try one more time to create the store
+            store = [self addPersistentStoreWithType:NSSQLiteStoreType
+                                       configuration:nil
+                                                 URL:url
+                                             options:options
+                                               error:&error];
+            if (store) {
+                // If we successfully added a store, remove the error that was initially created
+                error = nil;
+            }
+        }
+
         [MagicalRecord handleErrors:error];
     }
     return store;

Core/MagicalRecord+Options.h

@@ -20,6 +20,14 @@
 + (void) setShouldAutoCreateManagedObjectModel:(BOOL)shouldAutoCreate;
 + (BOOL) shouldAutoCreateDefaultPersistentStoreCoordinator;
 + (void) setShouldAutoCreateDefaultPersistentStoreCoordinator:(BOOL)shouldAutoCreate;
++ (void) setShouldDeleteStoreOnModelMismatch:(BOOL)shouldDeleteStoreOnModelMismatch;
+
+/*!
+ @method shouldDeleteStoreOnModelMistmatch
+ @abstract If true, when configuring the persistant store coordinator, and Magical Record encounters a store that does not match the model, it will attempt to remove it and re-create a new store.
+ This is extremely useful during development where every model change could potentially require a delete/reinstall of the app.
+ */
++ (BOOL) shouldDeleteStoreOnModelMismatch;
 
 
 @end

Core/MagicalRecord+Options.m

@@ -10,6 +10,7 @@
 
 static BOOL shouldAutoCreateManagedObjectModel_;
 static BOOL shouldAutoCreateDefaultPersistentStoreCoordinator_;
+static BOOL shouldDeleteStoreOnModelMismatch_;
 
 @implementation MagicalRecord (Options)
 
@@ -35,4 +36,14 @@ + (void) setShouldAutoCreateDefaultPersistentStoreCoordinator:(BOOL)shouldAutoCr
     shouldAutoCreateDefaultPersistentStoreCoordinator_ = shouldAutoCreate;
 }
 
++ (BOOL) shouldDeleteStoreOnModelMismatch;
+{
+    return shouldDeleteStoreOnModelMismatch_;
+}
+
++ (void) setShouldDeleteStoreOnModelMismatch:(BOOL)shouldDeleteStoreOnModelMismatch
+{
+    shouldDeleteStoreOnModelMismatch_ = shouldDeleteStoreOnModelMismatch;
+}
+
 @end

Core/MagicalRecord.m

@@ -91,6 +91,11 @@ + (void) initialize;
 #endif
         [self setShouldAutoCreateManagedObjectModel:YES];
         [self setShouldAutoCreateDefaultPersistentStoreCoordinator:NO];
+#ifdef DEBUG
+        [self setShouldDeleteStoreOnModelMismatch:YES];
+#else
+        [self setShouldDeleteStoreOnModelMismatch:NO];
+#endif
     }
 }