Added object to single section selection delegate callback

Summary:
- Updated selectionDelegate to pass through the model object
- Changelog entry under 3.0.0 as is breaking change

Try saying single section selection 10 times quick
Dabbing my left toe into some ObjC, so apologies if I violate years of rules

- [ ] Update documentation internally

Closes #396

- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Closes #397

Differential Revision: D4406213

Pulled By: rnystrom

fbshipit-source-id: ba468fa49e75823796a47da6ed7f0e8957db3d75

CHANGELOG.md

@@ -2,13 +2,29 @@
 
 The changelog for `IGListKit`. Also see the [releases](https://github.com/instagram/IGListKit/releases) on GitHub.
 
+3.0.0 (**upcoming release**)
+-----
+
+This release closes the [3.0.0 milestone](https://github.com/Instagram/IGListKit/milestone/3).
+
+### Breaking Changes
+
+- Updated `didSelect` delegate call in `IGListSingleSectionControllerDelegate` to include object. [Sherlouk](https://github.com/Sherlouk) [(#397)](https://github.com/Instagram/IGListKit/pull/397)
+
+```objc
+// OLD
+- (void)didSelectSingleSectionController:(IGListSingleSectionController *)sectionController;
+
+// NEW
+- (void)didSelectSectionController:(IGListSingleSectionController *)sectionController
+                        withObject:(id)object;
+```
+
 2.2.0
 -----
 
 This release closes the [2.2.0 milestone](https://github.com/Instagram/IGListKit/milestone/4).
 
-### Enhancements
-
 ### Fixes
 
 - Fix bug where emptyView's hidden status is not updated after the number of items is changed with `insertInSectionController:atIndexes:` or related methods. [Peter Edmonston](https://github.com/edmonston) [(#395)](https://github.com/Instagram/IGListKit/pull/395)

Examples/Examples-iOS/IGListKitExamples/ViewControllers/SingleSectionStoryboardViewController.swift

@@ -55,13 +55,11 @@ final class SingleSectionStoryboardViewController: UIViewController, IGListAdapt
         return sectionController
     }
 
-    func emptyView(for listAdapter: IGListAdapter) -> UIView? {
-        return nil
-    }
+    func emptyView(for listAdapter: IGListAdapter) -> UIView? { return nil }
 
     // MARK: - IGListSingleSectionControllerDelegate
 
-    func didSelect(_ sectionController: IGListSingleSectionController) {
+    func didSelect(_ sectionController: IGListSingleSectionController, with object: Any) {
         let section = adapter.section(for: sectionController) + 1
         let alert = UIAlertController(title: "Section \(section) was selected \u{1F389}", message: nil, preferredStyle: .alert)
         alert.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: nil))

Examples/Examples-iOS/IGListKitExamples/ViewControllers/SingleSectionViewController.swift

@@ -69,9 +69,11 @@ final class SingleSectionViewController: UIViewController, IGListAdapterDataSour
 
     // MARK: - IGListSingleSectionControllerDelegate
 
-    func didSelect(_ sectionController: IGListSingleSectionController) {
+    func didSelect(_ sectionController: IGListSingleSectionController, with object: Any) {
         let section = adapter.section(for: sectionController) + 1
-        let alert = UIAlertController(title: "Section \(section) was selected \u{1F389}", message: nil, preferredStyle: .alert)
+        let alert = UIAlertController(title: "Section \(section) was selected \u{1F389}",
+                                      message: "Cell Object: " + String(describing: object),
+                                      preferredStyle: .alert)
         alert.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: nil))
         present(alert, animated: true, completion: nil)
     }

Source/IGListSingleSectionController.h

@@ -45,8 +45,10 @@ typedef CGSize (^IGListSingleSectionCellSizeBlock)(id item, id<IGListCollectionC
  Tells the delegate that the section controller was selected.
 
  @param sectionController The section controller that was selected.
+ @param object            The model for the given section.
  */
-- (void)didSelectSingleSectionController:(IGListSingleSectionController *)sectionController;
+- (void)didSelectSectionController:(IGListSingleSectionController *)sectionController
+                        withObject:(id)object;
 
 @end
 

Source/IGListSingleSectionController.m

@@ -106,7 +106,7 @@ - (void)didUpdateToObject:(id)object {
 }
 
 - (void)didSelectItemAtIndex:(NSInteger)index {
-    [self.selectionDelegate didSelectSingleSectionController:self];
+    [self.selectionDelegate didSelectSectionController:self withObject:self.item];
 }
 
 @end

Tests/IGListSingleSectionControllerTests.m

@@ -126,7 +126,7 @@ - (void)test_whenSelected_thatDelegateReceivesEvent {
     IGListSingleSectionController *section = [self.adapter sectionControllerForObject:self.dataSource.objects.firstObject];
     id mockDelegate = [OCMockObject mockForProtocol:@protocol(IGListSingleSectionControllerDelegate)];
     section.selectionDelegate = mockDelegate;
-    [[mockDelegate expect] didSelectSingleSectionController:section];
+    [[mockDelegate expect] didSelectSectionController:section withObject:self.dataSource.objects.firstObject];
     [self.adapter collectionView:self.collectionView didSelectItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
     [mockDelegate verify];
 }