react-native/React/CxxModule/RCTNativeModule.mm

/**
 * 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 "RCTNativeModule.h"

#import <React/RCTBridge.h>
#import <React/RCTBridgeMethod.h>
#import <React/RCTBridgeModule.h>
#import <React/RCTCxxUtils.h>
#import <React/RCTFollyConvert.h>
#import <React/RCTLog.h>
#import <React/RCTProfile.h>
#import <React/RCTUtils.h>

#ifdef WITH_FBSYSTRACE
#include <fbsystrace.h>
#endif

namespace facebook {
namespace react {

static MethodCallResult invokeInner(RCTBridge *bridge, RCTModuleData *moduleData, unsigned int methodId, const folly::dynamic &params);

RCTNativeModule::RCTNativeModule(RCTBridge *bridge, RCTModuleData *moduleData)
    : m_bridge(bridge)
    , m_moduleData(moduleData) {}

std::string RCTNativeModule::getName() {
  return [m_moduleData.name UTF8String];
}

std::vector<MethodDescriptor> RCTNativeModule::getMethods() {
  std::vector<MethodDescriptor> descs;

  for (id<RCTBridgeMethod> method in m_moduleData.methods) {
    descs.emplace_back(
      method.JSMethodName,
      RCTFunctionDescriptorFromType(method.functionType)
    );
  }

  return descs;
}

folly::dynamic RCTNativeModule::getConstants() {
  RCT_PROFILE_BEGIN_EVENT(RCTProfileTagAlways,
    @"[RCTNativeModule getConstants] moduleData.exportedConstants", nil);
  NSDictionary *constants = m_moduleData.exportedConstants;
  folly::dynamic ret = convertIdToFollyDynamic(constants);
  RCT_PROFILE_END_EVENT(RCTProfileTagAlways, @"");
  return ret;
}

void RCTNativeModule::invoke(unsigned int methodId, folly::dynamic &&params, int callId) {
  // capture by weak pointer so that we can safely use these variables in a callback
  __weak RCTBridge *weakBridge = m_bridge;
  __weak RCTModuleData *weakModuleData = m_moduleData;
  // The BatchedBridge version of this buckets all the callbacks by thread, and
  // queues one block on each.  This is much simpler; we'll see how it goes and
  // iterate.
  dispatch_block_t block = [weakBridge, weakModuleData, methodId, params=std::move(params), callId] {
    #ifdef WITH_FBSYSTRACE
    if (callId != -1) {
      fbsystrace_end_async_flow(TRACE_TAG_REACT_APPS, "native", callId);
    }
    #endif
    invokeInner(weakBridge, weakModuleData, methodId, std::move(params));
  };

  if (m_bridge.valid) {
    dispatch_queue_t queue = m_moduleData.methodQueue;
    if (queue == RCTJSThread) {
      block();
    } else if (queue) {
      dispatch_async(queue, block);
    }
  } else {
    RCTLog(@"Attempted to invoke `%u` (method ID) on `%@` (NativeModule name) with an invalid bridge.",
               methodId, m_moduleData.name);
  }
}

MethodCallResult RCTNativeModule::callSerializableNativeHook(unsigned int reactMethodId, folly::dynamic &&params) {
  return invokeInner(m_bridge, m_moduleData, reactMethodId, params);
}

static MethodCallResult invokeInner(RCTBridge *bridge, RCTModuleData *moduleData, unsigned int methodId, const folly::dynamic &params) {
  if (!bridge || !bridge.valid || !moduleData) {
    return folly::none;
  }

  id<RCTBridgeMethod> method = moduleData.methods[methodId];
  if (RCT_DEBUG && !method) {
    RCTLogError(@"Unknown methodID: %ud for module: %@",
                methodId, moduleData.name);
  }

  NSArray *objcParams = convertFollyDynamicToId(params);
  @try {
    id result = [method invokeWithBridge:bridge module:moduleData.instance arguments:objcParams];
    return convertIdToFollyDynamic(result);
  }
  @catch (NSException *exception) {
    // Pass on JS exceptions
    if ([exception.name hasPrefix:RCTFatalExceptionName]) {
      @throw exception;
    }

    NSString *message = [NSString stringWithFormat:
                         @"Exception '%@' was thrown while invoking %s on target %@ with params %@\ncallstack: %@",
                         exception, method.JSMethodName, moduleData.name, objcParams, exception.callStackSymbols];
    RCTFatal(RCTErrorWithMessage(message));
  }

  return folly::none;
}

}
}