From 10acccc86d5b296995d6dacdf80b973bb10e4fc4 Mon Sep 17 00:00:00 2001
From: Peter Argany <petetheheat@fb.com>
Date: Wed, 31 Mar 2021 16:37:02 -0700
Subject: [PATCH] Handle commands in RCTLegacyViewManagerInteropCoordinator
 [3/n]

Summary:
Problem: `RCTLegacyViewManagerInteropCoordinator.mm` handles view commands by looking up `RCTModuleData` from the bridge, and then dispatching that method. In bridgeless mode, `RCTModuleData` doesn't exist.

Solution: Instead of relying on `RCTModuleData` (which does a ton of things), manually create a `_moduleMethods` array to store the methods that view manager exposes. This manual creation code was copied from how `RCTModuleData` performs lookup.

Changelog: [Internal]

Reviewed By: sammy-SC

Differential Revision: D27377257

fbshipit-source-id: c3e820808e6aca03bae6486d5510156b39462215
---
 .../RCTLegacyViewManagerInteropCoordinator.mm | 67 ++++++++++++++++---
 1 file changed, 58 insertions(+), 9 deletions(-)

diff --git a/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm b/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
index cab75ac3882..e651dfc4638 100644
--- a/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
+++ b/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
@@ -12,10 +12,12 @@
 #include <React/RCTEventDispatcherProtocol.h>
 #include <React/RCTFollyConvert.h>
 #include <React/RCTModuleData.h>
+#include <React/RCTModuleMethod.h>
 #include <React/RCTUIManager.h>
 #include <React/RCTUIManagerUtils.h>
 #include <React/RCTUtils.h>
 #include <folly/json.h>
+#include <objc/runtime.h>
 
 using namespace facebook::react;
 
@@ -23,13 +25,20 @@ using namespace facebook::react;
   RCTComponentData *_componentData;
   __weak RCTBridge *_bridge;
   /*
-   Each instnace of `RCTLegacyViewManagerInteropComponentView` registers a block to which events are dispatched.
+   Each instance of `RCTLegacyViewManagerInteropComponentView` registers a block to which events are dispatched.
    This is the container that maps unretained UIView pointer to a block to which the event is dispatched.
    */
   NSMutableDictionary<NSNumber *, InterceptorBlock> *_eventInterceptors;
+
+  /*
+   * In bridgeless mode, instead of using the bridge to look up RCTModuleData,
+   * store that information locally.
+   */
+  NSMutableArray<id<RCTBridgeMethod>> *_moduleMethods;
+  NSMutableDictionary<NSString *, id<RCTBridgeMethod>> *_moduleMethodsByName;
 }
 
-- (instancetype)initWithComponentData:(RCTComponentData *)componentData bridge:(RCTBridge *)bridge;
+- (instancetype)initWithComponentData:(RCTComponentData *)componentData bridge:(RCTBridge *)bridge
 {
   if (self = [super init]) {
     _componentData = componentData;
@@ -81,12 +90,13 @@ using namespace facebook::react;
 - (void)handleCommand:(NSString *)commandName args:(NSArray *)args reactTag:(NSInteger)tag
 {
   Class managerClass = _componentData.managerClass;
+  [self _lookupModuleMethodsIfNecessary];
   RCTModuleData *moduleData = [_bridge.batchedBridge moduleDataForName:RCTBridgeModuleNameForClass(managerClass)];
   id<RCTBridgeMethod> method;
   if ([commandName isKindOfClass:[NSNumber class]]) {
-    method = moduleData.methods[[commandName intValue]];
+    method = moduleData ? moduleData.methods[[commandName intValue]] : _moduleMethods[[commandName intValue]];
   } else if ([commandName isKindOfClass:[NSString class]]) {
-    method = moduleData.methodsByName[commandName];
+    method = moduleData ? moduleData.methodsByName[commandName] : _moduleMethodsByName[commandName];
     if (method == nil) {
       RCTLogError(@"No command found with name \"%@\"", commandName);
     }
@@ -96,12 +106,51 @@ using namespace facebook::react;
   }
 
   NSArray *newArgs = [@[ [NSNumber numberWithInteger:tag] ] arrayByAddingObjectsFromArray:args];
-  [_bridge.batchedBridge
-      dispatchBlock:^{
-        [method invokeWithBridge:self->_bridge module:self->_componentData.manager arguments:newArgs];
-        [self->_bridge.uiManager setNeedsLayout];
+
+  if (_bridge) {
+    [_bridge.batchedBridge
+        dispatchBlock:^{
+          [method invokeWithBridge:self->_bridge module:self->_componentData.manager arguments:newArgs];
+          [self->_bridge.uiManager setNeedsLayout];
+        }
+                queue:RCTGetUIManagerQueue()];
+  } else {
+    // TODO T86826778 - Figure out which queue this should be dispatched to.
+    [method invokeWithBridge:nil module:self->_componentData.manager arguments:newArgs];
+  }
+}
+
+#pragma mark - Private
+
+// This is copy-pasta from RCTModuleData.
+- (void)_lookupModuleMethodsIfNecessary
+{
+  if (!_bridge && !_moduleMethods) {
+    _moduleMethods = [NSMutableArray new];
+    _moduleMethodsByName = [NSMutableDictionary new];
+
+    unsigned int methodCount;
+    Class cls = _componentData.managerClass;
+    while (cls && cls != [NSObject class] && cls != [NSProxy class]) {
+      Method *methods = class_copyMethodList(object_getClass(cls), &methodCount);
+
+      for (unsigned int i = 0; i < methodCount; i++) {
+        Method method = methods[i];
+        SEL selector = method_getName(method);
+        if ([NSStringFromSelector(selector) hasPrefix:@"__rct_export__"]) {
+          IMP imp = method_getImplementation(method);
+          auto exportedMethod = ((const RCTMethodInfo *(*)(id, SEL))imp)(_componentData.managerClass, selector);
+          id<RCTBridgeMethod> moduleMethod =
+              [[RCTModuleMethod alloc] initWithExportedMethod:exportedMethod moduleClass:_componentData.managerClass];
+          [_moduleMethodsByName setValue:moduleMethod forKey:[NSString stringWithUTF8String:moduleMethod.JSMethodName]];
+          [_moduleMethods addObject:moduleMethod];
+        }
       }
-              queue:RCTGetUIManagerQueue()];
+
+      free(methods);
+      cls = class_getSuperclass(cls);
+    }
+  }
 }
 
 @end