Merge pull request #886 from ParsePlatform/nlutsenko.latest

Add APIs to load current user, installation, config asynchronously.

Author: nlutsenko

Parse/Internal/ParseManager.m

@@ -427,12 +427,15 @@ - (BFTask *)preloadDiskObjectsToMemoryAsync {
     @weakify(self);
     return [BFTask taskFromExecutor:[BFExecutor executorWithDispatchQueue:_preloadQueue] withBlock:^id{
         @strongify(self);
-        [PFUser currentUser];
-        [PFConfig currentConfig];
+
+        NSArray *tasks = @[
+                           [PFUser getCurrentUserInBackground],
+                           [PFConfig getCurrentConfigInBackground],
 #if !TARGET_OS_WATCH && !TARGET_OS_TV
-        [PFInstallation currentInstallation];
+                           [PFInstallation getCurrentInstallationInBackground],
 #endif
-        
+                           ];
+        [[BFTask taskForCompletionOfAllTasks:tasks] waitUntilFinished]; // Wait synchronously to make sure we are blocking preload queue.
         [self eventuallyQueue];
 
         return nil;

Parse/PFConfig.h

@@ -38,6 +38,15 @@ typedef void(^PFConfigResultBlock)(PFConfig *_Nullable config, NSError *_Nullabl
  */
 + (PFConfig *)currentConfig;
 
+/**
+ Returns the task that encapsulates the most recently fetched config.
+
+ If there was no config fetched - this method will return an empty instance of `PFConfig`.
+
+ @return Task that encapsulates current, last fetched instance of PFConfig.
+ */
++ (BFTask<PFConfig *> *)getCurrentConfigInBackground;
+
 ///--------------------------------------
 #pragma mark - Retrieving Config
 ///--------------------------------------

Parse/PFConfig.m

@@ -40,8 +40,11 @@ + (PFConfigController *)_configController {
 #pragma mark Public
 
 + (PFConfig *)currentConfig {
-    return [[[self _configController].currentConfigController getCurrentConfigAsync] waitForResult:nil
-                                                                             withMainThreadWarning:NO];
+    return [[self getCurrentConfigInBackground] waitForResult:nil withMainThreadWarning:NO];
+}
+
++ (BFTask<PFConfig *> *)getCurrentConfigInBackground {
+    return [[self _configController].currentConfigController getCurrentConfigAsync];
 }
 
 ///--------------------------------------

Parse/PFInstallation.h

@@ -44,14 +44,23 @@ PF_TV_UNAVAILABLE PF_WATCH_UNAVAILABLE @interface PFInstallation : PFObject<PFSu
 /**
  Gets the currently-running installation from disk and returns an instance of it.
 
- If this installation is not stored on disk, returns a `PFInstallation`
- with `deviceType` and `installationId` fields set to those of the
- current installation.
+ If this installation is not stored on disk this method will create a new `PFInstallation`
+ with `deviceType` and `installationId` fields set to those of the current installation.
 
  @result Returns a `PFInstallation` that represents the currently-running installation.
  */
 + (instancetype)currentInstallation;
 
+/**
+ *Asynchronously* loads the currently-running installation from disk and returns an instance of it.
+
+ If this installation is not stored on disk this method will create a new `PFInstallation`
+ with `deviceType` and `installationId` fields set to those of the current installation.
+
+ @result Returns a task that incapsulates the current installation.
+ */
++ (BFTask<__kindof PFInstallation *> *)getCurrentInstallationInBackground;
+
 ///--------------------------------------
 #pragma mark - Installation Properties
 ///--------------------------------------

Parse/PFInstallation.m

@@ -132,8 +132,11 @@ + (PFQuery *)query {
 ///--------------------------------------
 
 + (instancetype)currentInstallation {
-    BFTask *task = [[self _currentInstallationController] getCurrentObjectAsync];
-    return [task waitForResult:nil withMainThreadWarning:NO];
+    return [[self getCurrentInstallationInBackground] waitForResult:nil withMainThreadWarning:NO];
+}
+
++ (BFTask<__kindof PFInstallation *> *)getCurrentInstallationInBackground {
+    return [[self _currentInstallationController] getCurrentObjectAsync];
 }
 
 ///--------------------------------------

Parse/PFUser.h

@@ -45,6 +45,13 @@ typedef void(^PFUserLogoutResultBlock)(NSError *_Nullable error);
  */
 + (nullable instancetype)currentUser;
 
+/**
+ *Asynchronously* loads the currently logged in user from disk and returns a task that encapsulates it.
+
+ @return The task that encapsulates the work being done.
+ */
++ (BFTask<__kindof PFUser *> *)getCurrentUserInBackground;
+
 /**
  The session token for the `PFUser`.
 

Parse/PFUser.m

@@ -780,8 +780,11 @@ + (NSString *)parseClassName {
 }
 
 + (instancetype)currentUser {
-    PFCurrentUserController *controller = [[self class] currentUserController];
-    return [[controller getCurrentObjectAsync] waitForResult:nil withMainThreadWarning:NO];
+    return [[self getCurrentUserInBackground] waitForResult:nil withMainThreadWarning:NO];
+}
+
++ (BFTask<__kindof PFUser *> *)getCurrentUserInBackground {
+    return [[[self class] currentUserController] getCurrentObjectAsync];
 }
 
 - (BOOL)_current {