Refactor SKSubDescriptor

Reviewed By: d16r

Differential Revision: D20458337

fbshipit-source-id: e8ea848c6e2f7521c5a6c6eb4110bba0bfe25593

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/FlipperKitLayoutComponentKitSupport.h

@@ -8,13 +8,9 @@
 #import <Foundation/Foundation.h>
 
 #import <FlipperKitLayoutPlugin/SKDescriptorMapper.h>
-#import "SKSubDescriptor.h"
 
 @interface FlipperKitLayoutComponentKitSupport : NSObject
 
 + (void)setUpWithDescriptorMapper:(SKDescriptorMapper*)mapper;
 
-+ (void)setUpWithDescriptorMapper:(SKDescriptorMapper*)mapper
-                   subDescriptors:(NSArray<SKSubDescriptor*>*)subDescriptors;
-
 @end

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/FlipperKitLayoutComponentKitSupport.mm

@@ -17,22 +17,9 @@
 #import "SKComponentLayoutDescriptor.h"
 #import "SKComponentLayoutWrapper.h"
 #import "SKComponentRootViewDescriptor.h"
-#import "SKSubDescriptor.h"
 
 @implementation FlipperKitLayoutComponentKitSupport
 
-+ (void)setUpWithDescriptorMapper:(SKDescriptorMapper*)mapper
-                   subDescriptors:(NSArray<SKSubDescriptor*>*)subDescriptors {
-  [mapper registerDescriptor:[[SKComponentRootViewDescriptor alloc]
-                                 initWithDescriptorMapper:mapper]
-                    forClass:[CKComponentRootView class]];
-  SKComponentLayoutDescriptor* layoutDescriptor =
-      [[SKComponentLayoutDescriptor alloc] initWithDescriptorMapper:mapper];
-  [layoutDescriptor addSubDescriptors:subDescriptors];
-  [mapper registerDescriptor:layoutDescriptor
-                    forClass:[SKComponentLayoutWrapper class]];
-}
-
 + (void)setUpWithDescriptorMapper:(SKDescriptorMapper*)mapper {
   // What we really want here is "forProtocol:@protocol(CKInspectableView)" but
   // no such luck.

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.h

@@ -14,6 +14,7 @@
 @interface SKComponentLayoutDescriptor
     : SKNodeDescriptor<SKComponentLayoutWrapper*>
 
-- (void)addSubDescriptors:(NSArray<SKSubDescriptor*>*)subDescriptors;
++ (void)registerSubDescriptor:(SKSubDescriptor)descriptor
+                      forName:(NSString*)name;
 
 @end

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.mm

@@ -9,6 +9,9 @@
 
 #import "SKComponentLayoutDescriptor.h"
 
+#import <utility>
+#import <vector>
+
 #import <ComponentKit/CKComponent.h>
 #import <ComponentKit/CKComponentAccessibility.h>
 #import <ComponentKit/CKComponentActionInternal.h>
@@ -29,15 +32,18 @@
 #import "SKSubDescriptor.h"
 #import "Utils.h"
 
-@implementation SKComponentLayoutDescriptor {
-  NSArray<SKSubDescriptor*>* _registeredSubdescriptors;
+@implementation SKComponentLayoutDescriptor
+
+static std::vector<std::pair<NSString*, SKSubDescriptor>>& subDescriptors() {
+  // Avoid a global constructor; we want to lazily initialize this when needed.
+  static std::vector<std::pair<NSString*, SKSubDescriptor>> d;
+  return d;
 }
 
-- (void)setUp {
-  [super setUp];
-
-  if (!_registeredSubdescriptors) {
-    _registeredSubdescriptors = [NSArray new];
++ (void)registerSubDescriptor:(SKSubDescriptor)descriptor
+                      forName:(NSString*)name {
+  if (name && descriptor) {
+    subDescriptors().push_back({name, descriptor});
   }
 }
 
@@ -90,8 +96,8 @@
   NSMutableDictionary<NSString*, NSObject*>* extraData =
       [[NSMutableDictionary alloc] init];
 
-  for (SKSubDescriptor* s in _registeredSubdescriptors) {
-    [extraData setObject:[s getDataForNode:node] forKey:[s getName]];
+  for (const auto& pair : subDescriptors()) {
+    [extraData setObject:pair.second(node) forKey:pair.first];
   }
   if (extraData.count > 0) {
     [data addObject:[SKNamed newWithName:@"Extra Sections"
@@ -102,10 +108,6 @@
   return data;
 }
 
-- (void)addSubDescriptors:(nonnull NSArray<SKSubDescriptor*>*)subDescriptors {
-  _registeredSubdescriptors = subDescriptors;
-}
-
 - (NSDictionary<NSString*, NSObject*>*)propsForFlexboxChild:
     (CKFlexboxComponentChild)child {
   return @{

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKSubDescriptor.h

@@ -10,20 +10,8 @@
 @class SKComponentLayoutWrapper;
 
 /**
- A SKSubDescriptor is an object which knows how to expose an Object of type T
- to the SKLayoutDescriptor. This class is for frameworks wanting to pass data
+ A SKSubDescriptor is a function which knows how to expose additional data
+ to SKLayoutDescriptor. This class is for frameworks wanting to pass data
  along through the Layout Descriptor.
  */
-@interface SKSubDescriptor : NSObject
-
-/**
- This is the SubDescriptor name.
- */
-- (NSString*)getName;
-
-/**
- This is the data the SubDescriptor wants to pass up to the SKLayoutDescriptor.
- */
-- (NSString*)getDataForNode:(SKComponentLayoutWrapper*)node;
-
-@end
+typedef NSString* (*SKSubDescriptor)(SKComponentLayoutWrapper* node);

iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKSubDescriptor.mm

@@ -4,24 +4,3 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-
-#if FB_SONARKIT_ENABLED
-
-#import "SKSubDescriptor.h"
-#import "SKComponentLayoutWrapper.h"
-
-@implementation SKSubDescriptor {
-}
-
-- (NSDictionary<NSString*, NSObject*>*)getDataForNode:
-    (SKComponentLayoutWrapper*)node {
-  return @{};
-}
-
-- (NSString*)getName {
-  return @"";
-}
-
-@end
-
-#endif