IGListKit/Source/IGListDiffKit/IGListDiffable.h
Nate Stedman e4c60650f2 Split IGListKit and IGListDiffKit (#1377)
Summary:
Pull Request resolved: https://github.com/Instagram/IGListKit/pull/1377

This splits the diffing-only components from `IGListKit` out into a separate library, `IGListDiffKit`, allowing them to be used independently of the rest of `IGListKit`. We've found that the diffing components of the library are useful independently of the rest of the `UICollectionView` infrastructure, and separating the libraries allows apps to take advantage of those components without paying the full binary size cost of `IGListKit`. The diffing components are available as a subspec in Cocoapods, and as an independent framework in Carthage and direct Xcode project import (i.e. Git submodules).

This is a breaking change, necessitating a major version bump, although it should have only minor impact for projects using the umbrella header `IGListKit.h`, as that header continues to import the diffing utilities. In particular, for a project using Cocoapods and importing `IGListKit.h`, there should be no code changes required.

Reviewed By: calimarkus

Differential Revision: D18114249

fbshipit-source-id: 363b5a427e32800bbc6e82f897230963b4167245
2019-10-31 08:26:12 -07:00

38 lines
1.1 KiB
Objective-C

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#import <Foundation/Foundation.h>
/**
The `IGListDiffable` protocol provides methods needed to compare the identity and equality of two objects.
*/
NS_SWIFT_NAME(ListDiffable)
@protocol IGListDiffable
/**
Returns a key that uniquely identifies the object.
@return A key that can be used to uniquely identify the object.
@note Two objects may share the same identifier, but are not equal. A common pattern is to use the `NSObject`
category for automatic conformance. However this means that objects will be identified on their
pointer value so finding updates becomes impossible.
@warning This value should never be mutated.
*/
- (nonnull id<NSObject>)diffIdentifier;
/**
Returns whether the receiver and a given object are equal.
@param object The object to be compared to the receiver.
@return `YES` if the receiver and object are equal, otherwise `NO`.
*/
- (BOOL)isEqualToDiffableObject:(nullable id<IGListDiffable>)object;
@end