react-native/React/Base/RCTBridgeModule.h

333 lines
12 KiB
Objective-C

/**
* 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 <Foundation/Foundation.h>
#import <React/RCTDefines.h>
@class RCTBridge;
@protocol RCTBridgeMethod;
/**
* The type of a block that is capable of sending a response to a bridged
* operation. Use this for returning callback methods to JS.
*/
typedef void (^RCTResponseSenderBlock)(NSArray *response);
/**
* The type of a block that is capable of sending an error response to a
* bridged operation. Use this for returning error information to JS.
*/
typedef void (^RCTResponseErrorBlock)(NSError *error);
/**
* Block that bridge modules use to resolve the JS promise waiting for a result.
* Nil results are supported and are converted to JS's undefined value.
*/
typedef void (^RCTPromiseResolveBlock)(id result);
/**
* Block that bridge modules use to reject the JS promise waiting for a result.
* The error may be nil but it is preferable to pass an NSError object for more
* precise error messages.
*/
typedef void (^RCTPromiseRejectBlock)(NSString *code, NSString *message, NSError *error);
/**
* This constant can be returned from +methodQueue to force module
* methods to be called on the JavaScript thread. This can have serious
* implications for performance, so only use this if you're sure it's what
* you need.
*
* NOTE: RCTJSThread is not a real libdispatch queue
*/
RCT_EXTERN dispatch_queue_t RCTJSThread;
RCT_EXTERN_C_BEGIN
typedef struct RCTMethodInfo {
const char *const jsName;
const char *const objcName;
const BOOL isSync;
} RCTMethodInfo;
RCT_EXTERN_C_END
/**
* Provides the interface needed to register a bridge module.
*/
@protocol RCTBridgeModule <NSObject>
/**
* Place this macro in your class implementation to automatically register
* your module with the bridge when it loads. The optional js_name argument
* will be used as the JS module name. If omitted, the JS module name will
* match the Objective-C class name.
*/
#define RCT_EXPORT_MODULE(js_name) \
RCT_EXTERN void RCTRegisterModule(Class); \
+ (NSString *)moduleName { return @#js_name; } \
+ (void)load { RCTRegisterModule(self); }
/**
* To improve startup performance users may want to generate their module lists
* at build time and hook the delegate to merge with the runtime list. This
* macro takes the place of the above for those cases by omitting the +load
* generation.
*
*/
#define RCT_EXPORT_PRE_REGISTERED_MODULE(js_name) \
+ (NSString *)moduleName { return @#js_name; }
// Implemented by RCT_EXPORT_MODULE
+ (NSString *)moduleName;
@optional
/**
* A reference to the RCTBridge. Useful for modules that require access
* to bridge features, such as sending events or making JS calls. This
* will be set automatically by the bridge when it initializes the module.
* To implement this in your module, just add `@synthesize bridge = _bridge;`
* If using Swift, add `@objc var bridge: RCTBridge!` to your module.
*/
@property (nonatomic, weak, readonly) RCTBridge *bridge;
/**
* The queue that will be used to call all exported methods. If omitted, this
* will call on a default background queue, which is avoids blocking the main
* thread.
*
* If the methods in your module need to interact with UIKit methods, they will
* probably need to call those on the main thread, as most of UIKit is main-
* thread-only. You can tell React Native to call your module methods on the
* main thread by returning a reference to the main queue, like this:
*
* - (dispatch_queue_t)methodQueue
* {
* return dispatch_get_main_queue();
* }
*
* If you don't want to specify the queue yourself, but you need to use it
* inside your class (e.g. if you have internal methods that need to dispatch
* onto that queue), you can just add `@synthesize methodQueue = _methodQueue;`
* and the bridge will populate the methodQueue property for you automatically
* when it initializes the module.
*/
@property (nonatomic, strong, readonly) dispatch_queue_t methodQueue;
/**
* Wrap the parameter line of your method implementation with this macro to
* expose it to JS. By default the exposed method will match the first part of
* the Objective-C method selector name (up to the first colon). Use
* RCT_REMAP_METHOD to specify the JS name of the method.
*
* For example, in ModuleName.m:
*
* - (void)doSomething:(NSString *)aString withA:(NSInteger)a andB:(NSInteger)b
* { ... }
*
* becomes
*
* RCT_EXPORT_METHOD(doSomething:(NSString *)aString
* withA:(NSInteger)a
* andB:(NSInteger)b)
* { ... }
*
* and is exposed to JavaScript as `NativeModules.ModuleName.doSomething`.
*
* ## Promises
*
* Bridge modules can also define methods that are exported to JavaScript as
* methods that return a Promise, and are compatible with JS async functions.
*
* Declare the last two parameters of your native method to be a resolver block
* and a rejecter block. The resolver block must precede the rejecter block.
*
* For example:
*
* RCT_EXPORT_METHOD(doSomethingAsync:(NSString *)aString
* resolver:(RCTPromiseResolveBlock)resolve
* rejecter:(RCTPromiseRejectBlock)reject
* { ... }
*
* Calling `NativeModules.ModuleName.doSomethingAsync(aString)` from
* JavaScript will return a promise that is resolved or rejected when your
* native method implementation calls the respective block.
*
*/
#define RCT_EXPORT_METHOD(method) \
RCT_REMAP_METHOD(, method)
/**
* Same as RCT_EXPORT_METHOD but the method is called from JS
* synchronously **on the JS thread**, possibly returning a result.
*
* WARNING: in the vast majority of cases, you should use RCT_EXPORT_METHOD which
* allows your native module methods to be called asynchronously: calling
* methods synchronously can have strong performance penalties and introduce
* threading-related bugs to your native modules.
*
* The return type must be of object type (id) and should be serializable
* to JSON. This means that the hook can only return nil or JSON values
* (e.g. NSNumber, NSString, NSArray, NSDictionary).
*
* Calling these methods when running under the websocket executor
* is currently not supported.
*/
#define RCT_EXPORT_BLOCKING_SYNCHRONOUS_METHOD(method) \
RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(id, method)
#define RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(returnType, method) \
RCT_REMAP_BLOCKING_SYNCHRONOUS_METHOD(, returnType, method)
/**
* Similar to RCT_EXPORT_METHOD but lets you set the JS name of the exported
* method. Example usage:
*
* RCT_REMAP_METHOD(executeQueryWithParameters,
* executeQuery:(NSString *)query parameters:(NSDictionary *)parameters)
* { ... }
*/
#define RCT_REMAP_METHOD(js_name, method) \
_RCT_EXTERN_REMAP_METHOD(js_name, method, NO) \
- (void)method RCT_DYNAMIC;
/**
* Similar to RCT_EXPORT_BLOCKING_SYNCHRONOUS_METHOD but lets you set
* the JS name of the exported method. Example usage:
*
* RCT_EXPORT_BLOCKING_SYNCHRONOUS_METHOD(executeQueryWithParameters,
* executeQuery:(NSString *)query parameters:(NSDictionary *)parameters)
* { ... }
*/
#define RCT_REMAP_BLOCKING_SYNCHRONOUS_METHOD(js_name, returnType, method) \
_RCT_EXTERN_REMAP_METHOD(js_name, method, YES) \
- (returnType)method RCT_DYNAMIC;
/**
* Use this macro in a private Objective-C implementation file to automatically
* register an external module with the bridge when it loads. This allows you to
* register Swift or private Objective-C classes with the bridge.
*
* For example if one wanted to export a Swift class to the bridge:
*
* MyModule.swift:
*
* @objc(MyModule) class MyModule: NSObject {
*
* @objc func doSomething(string: String! withFoo a: Int, bar b: Int) { ... }
*
* }
*
* MyModuleExport.m:
*
* #import <React/RCTBridgeModule.h>
*
* @interface RCT_EXTERN_MODULE(MyModule, NSObject)
*
* RCT_EXTERN_METHOD(doSomething:(NSString *)string withFoo:(NSInteger)a bar:(NSInteger)b)
*
* @end
*
* This will now expose MyModule and the method to JavaScript via
* `NativeModules.MyModule.doSomething`
*/
#define RCT_EXTERN_MODULE(objc_name, objc_supername) \
RCT_EXTERN_REMAP_MODULE(, objc_name, objc_supername)
/**
* Like RCT_EXTERN_MODULE, but allows setting a custom JavaScript name.
*/
#define RCT_EXTERN_REMAP_MODULE(js_name, objc_name, objc_supername) \
objc_name : objc_supername \
@end \
@interface objc_name (RCTExternModule) <RCTBridgeModule> \
@end \
@implementation objc_name (RCTExternModule) \
RCT_EXPORT_MODULE(js_name)
/**
* Use this macro in accordance with RCT_EXTERN_MODULE to export methods
* of an external module.
*/
#define RCT_EXTERN_METHOD(method) \
_RCT_EXTERN_REMAP_METHOD(, method, NO)
/**
* Use this macro in accordance with RCT_EXTERN_MODULE to export methods
* of an external module that should be invoked synchronously.
*/
#define RCT_EXTERN__BLOCKING_SYNCHRONOUS_METHOD(method) \
_RCT_EXTERN_REMAP_METHOD(, method, YES)
/**
* Like RCT_EXTERN_REMAP_METHOD, but allows setting a custom JavaScript name
* and also whether this method is synchronous.
*/
#define _RCT_EXTERN_REMAP_METHOD(js_name, method, is_blocking_synchronous_method) \
+ (const RCTMethodInfo *)RCT_CONCAT(__rct_export__, RCT_CONCAT(js_name, RCT_CONCAT(__LINE__, __COUNTER__))) { \
static RCTMethodInfo config = {#js_name, #method, is_blocking_synchronous_method}; \
return &config; \
}
/**
* Most modules can be used from any thread. All of the modules exported non-sync method will be called on its
* methodQueue, and the module will be constructed lazily when its first invoked. Some modules have main need to access
* information that's main queue only (e.g. most UIKit classes). Since we don't want to dispatch synchronously to the
* main thread to this safely, we construct these moduels and export their constants ahead-of-time.
*
* Note that when set to false, the module constructor will be called from any thread.
*
* This requirement is currently inferred by checking if the module has a custom initializer or if there's exported
* constants. In the future, we'll stop automatically inferring this and instead only rely on this method.
*/
+ (BOOL)requiresMainQueueSetup;
/**
* Injects methods into JS. Entries in this array are used in addition to any
* methods defined using the macros above. This method is called only once,
* before registration.
*/
- (NSArray<id<RCTBridgeMethod>> *)methodsToExport;
/**
* Injects constants into JS. These constants are made accessible via NativeModules.ModuleName.X. It is only called once
* for the lifetime of the bridge, so it is not suitable for returning dynamic values, but may be used for long-lived
* values such as session keys, that are regenerated only as part of a reload of the entire React application.
*
* If you implement this method and do not implement `requiresMainThreadSetup`, you will trigger deprecated logic
* that eagerly initializes your module on bridge startup. In the future, this behaviour will be changed to default
* to initializing lazily, and even modules with constants will be initialized lazily.
*/
- (NSDictionary *)constantsToExport;
/**
* Notifies the module that a batch of JS method invocations has just completed.
*/
- (void)batchDidComplete;
/**
* Notifies the module that the active batch of JS method invocations has been
* partially flushed.
*
* This occurs before -batchDidComplete, and more frequently.
*/
- (void)partialBatchDidFlush;
@end
/**
* Experimental.
* A protocol to declare that a class supports JSI-bound NativeModule.
* This may be removed in the future.
*/
@protocol RCTJSINativeModule <NSObject>
@end