PFSubclassing.h

/**
 * Copyright (c) 2015-present, Parse, LLC.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

#import <Foundation/Foundation.h>

@class PFQuery<PFGenericObject : PFObject *>;

NS_ASSUME_NONNULL_BEGIN

/**
 If a subclass of `PFObject` conforms to `PFSubclassing` and calls `PFObject.+registerSubclass`,
 Parse framework will be able to use that class as the native class for a Parse cloud object.

 Classes conforming to this protocol should subclass `PFObject` and
 include `PFObject+Subclass.h` in their implementation file.
 This ensures the methods in the Subclass category of `PFObject` are exposed in its subclasses only.
 */
@protocol PFSubclassing <NSObject>

@required

/**
 The name of the class as seen in the REST API.
 */
+ (NSString *)parseClassName;

@optional

/**
 Constructs an object of the most specific class known to implement `+parseClassName`.

 This method takes care to help `PFObject` subclasses be subclassed themselves.
 For example, `PFUser.+object` returns a `PFUser` by default but will return an
 object of a registered subclass instead if one is known.
 A default implementation is provided by `PFObject` which should always be sufficient.

 @return Returns the object that is instantiated.
 */
+ (instancetype)object;

/**
 Creates a reference to an existing PFObject for use in creating associations between PFObjects.

 Calling `PFObject.dataAvailable` on this object will return `NO`
 until `PFObject.-fetchIfNeeded` has been called. No network request will be made.
 A default implementation is provided by `PFObject` which should always be sufficient.

 @param objectId The object id for the referenced object.

 @return A new `PFObject` without data.
 */
+ (instancetype)objectWithoutDataWithObjectId:(nullable NSString *)objectId PF_SWIFT_UNAVAILABLE;

/**
 Create a query which returns objects of this type.

 A default implementation is provided by `PFObject` which should always be sufficient.
 */
+ (nullable PFQuery *)query;

/**
 Returns a query for objects of this type with a given predicate.

 A default implementation is provided by `PFObject` which should always be sufficient.

 @param predicate The predicate to create conditions from.

 @return An instance of `PFQuery`.

 @see [PFQuery queryWithClassName:predicate:]
 */
+ (nullable PFQuery *)queryWithPredicate:(nullable NSPredicate *)predicate;

/**
 Lets Parse know this class should be used to instantiate all objects with class type `parseClassName`.

 @warning This method must be called before `Parse.+setApplicationId:clientKey:`.
 */
+ (void)registerSubclass;

@end

NS_ASSUME_NONNULL_END