//

// PFSubclassing.h

//

// Copyright 2011-present Parse Inc. All rights reserved.

//

#import <Foundation/Foundation.h>

#if TARGET_OS_IPHONE

#import <Parse/PFNullability.h>

#else

#import <ParseOSX/PFNullability.h>

#endif

@class PFQuery;

PF_ASSUME_NONNULL_BEGIN

/*!

If a subclass of <PFObject> conforms to `PFSubclassing` and calls <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

/*!

@abstract Constructs an object of the most specific class known to implement <parseClassName>.

@discussion 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.

@returns Returns the object that is instantiated.

*/

+ (instancetype)object;

/*!

@abstract Creates a reference to an existing PFObject for use in creating associations between PFObjects.

@discussion Calling <[PFObject isDataAvailable]> 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.

@returns A new <PFObject> without data.

*/

+ (instancetype)objectWithoutDataWithObjectId:(PF_NULLABLE NSString *)objectId;

/*!

@abstract The name of the class as seen in the REST API.

*/

+ (NSString *)parseClassName;

/*!

@abstract Create a query which returns objects of this type.

@discussion A default implementation is provided by <PFObject> which should always be sufficient.

*/

+ (PF_NULLABLE PFQuery *)query;

/*!

@abstract Returns a query for objects of this type with a given predicate.

@discussion A default implementation is provided by <PFObject> which should always be sufficient.

@param predicate The predicate to create conditions from.

@returns An instance of <PFQuery>.

@see [PFQuery queryWithClassName:predicate:]

*/

+ (PF_NULLABLE PFQuery *)queryWithPredicate:(PF_NULLABLE NSPredicate *)predicate;

/*!

@abstract 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

PF_ASSUME_NONNULL_END