# Swift In Weex

Swift and Objective-C mix-up

a complete demo

# extend module using swift

As we export moudle method using macro and calling in runtime, so we can extend module using swift by extensionbjective-C class.

You can also finish extending module by write an category for swift class in Objective-C class.

• new WXSwiftTestModule.h/m and WXSwiftTestModule.swift file ，you will get a tip as follow during the creation choose Create Bridging Header, as we need to access method in Objective-C in swift file, and the Bridging header can help us. And the format name of the header file is yourTarget-Bridging-Header.h, and mine is WeexDemo-Bridging-Header.h.

• implementation in WXSwiftTestModule.h/m

  • WXSwiftTestModule.h

    #import <Foundation/Foundation.h>
    #import <WeexSDK/WeexSDK.h>
    
    @interface WXSwiftTestModule : NSObject <WXModuleProtocol>
    
    @end
    

  • WXSwiftTestModule.m

    you can search WeexDemo-Swift.h after building your project, Xcode will generate this file for us.

    for simulator the file path may be:

    weex/ios/playground/DerivedData/WeexDemo/Build/Intermediates/WeexDemo.build/Debug-iphonesimulator/WeexDemo.build/DerivedSources/WeexDemo-Swift.h
    

    export method define in swift file.

    #import "WXSwiftTestModule.h"
    #import "WeexDemo-Swift.h" // you need to import the header to make Objective-C code recognize the method defined in swift file.
    
    @implementation WXSwiftTestModule
    #pragma clang diagnostic push //forbid unknow selector warrning
    #pragma clang diagnostic ignored "-Wundeclared-selector"
    
    WX_EXPORT_METHOD(@selector(printSome:callback:)) //method name in Swift, you can get the final method name in `WeexDemo-Swift.h` as the convert of Xcode.
    
    #pragma clang diagnostic pop
    
    @end
    

• in Swift make an extension for Objective-C class WXSwiftTestModule, add a method, and then export it in Objective-C, then we can use it in javaScript.

  • WXSwiftTestModule.swift

    import Foundation
    public extension WXSwiftTestModule {
      @objc(printSome:callback:)
      public func printSome(someThing:String, callback:WXModuleCallback) {
        print(someThing)
        callback(someThing)
      }
    }
    

  we need to expose WXSwiftTestModuleWXModuleCallback in WeexDemo-Bridging-Header as our Objective-C need to access them.

  Attention: Please add the @objc attribute to the method in the Swift file to avoid the error for the method cannot be found.

  • WeexDemo-Bridging-Header.h

    //
    //  Use this file to import your target's public headers that you would like to expose to Swift.
    //
    #import "WXSwiftTestModule.h"
    #import "WeexSDK.h"
    

    by far we have finished our module using swift.

  # module usage

  • register module to WeexSDK

    [WXSDKEngine registerModule:@"swifter" withClass:[WXSwiftTestModule class]];
    
    

  • front-end usage

    <template>
      <text>Swift Module</text>
    </template>
    
    <script>
      module.exports = {
        ready: function() {
          var swifter = weex.require('swifter');
          swifter.printSome("https://www.taobao.com",function(param){
            nativeLog(param);
          });
        }
      };
    </script>