Merge pull request #50 from Oni-zerone/release/0.5.1

Release/0.5.1

Example/Podfile.lock

@@ -1,9 +1,9 @@
 PODS:
-  - PowerTools (0.5.0):
-    - PowerTools/Core (= 0.5.0)
-  - PowerTools/CollectionVM (0.5.0):
+  - PowerTools (0.5.1):
+    - PowerTools/Core (= 0.5.1)
+  - PowerTools/CollectionVM (0.5.1):
     - PowerTools/Core
-  - PowerTools/Core (0.5.0)
+  - PowerTools/Core (0.5.1)
   - PowerToolsTester (0.4.0):
     - PowerToolsTester/CoreTester (= 0.4.0)
   - PowerToolsTester/CoreTester (0.4.0):
@@ -22,7 +22,7 @@ EXTERNAL SOURCES:
     :path: "../Tester/"
 
 SPEC CHECKSUMS:
-  PowerTools: 0d036e95e3bc1c3867be324e5023b107239df112
+  PowerTools: af8488b1f6dba2da567ab19bc37ad6f97bf83410
   PowerToolsTester: cce5270b189036bc1b7dda0b30773374be745165
 
 PODFILE CHECKSUM: e0af4d9ba0fe81ef397e2dd16c5f12eb9e08c1c6

PowerTools.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'PowerTools'
-  s.version          = '0.5.0'
+  s.version          = '0.5.1'
   s.summary          = 'Tools for fast and modular app development.'
   s.swift_version    = '5.1'
 

PowerTools/CollectionVM/Classes/DataStructure/ModelUpdate.swift

@@ -21,10 +21,9 @@ internal struct ModelUpdate {
 
     init(from oldModel: [SectionViewModel], to newModel: [SectionViewModel], forceReload: Bool = false) {
 
-        self.model = newModel
-
         if forceReload || newModel.shouldReload(from: oldModel) {
             self.change = nil
+            self.model = newModel
             return
         }
 
@@ -43,6 +42,7 @@ internal struct ModelUpdate {
         let deletions = oldLookupTable.calculateDeletions(countTable: countTable)
         changes.append(contentsOf: deletions)
         self.change = changes
+        self.model = newModel.merge(oldModel)
     }
 }
 
@@ -75,6 +75,22 @@ internal extension Array where Element == SectionViewModel {
         }
         return firstChange != nil
     }
+
+    func merge(_ oldModel: [SectionViewModel]) -> [SectionViewModel] {
+
+        let lookupTable = oldModel.lookupTable
+
+        return map { section in
+            var section = section
+            section.items = section.items.map { item in
+                guard let oldIndexPath = lookupTable[item.hashValue]?.first else {
+                    return item
+                }
+                return oldModel[oldIndexPath.section].items[oldIndexPath.item]
+            }
+            return section
+        }
+    }
 }
 
 fileprivate extension Dictionary where Key == Int, Value == [IndexPath] {