How to write Cordova plugin in Swift?

Question

I converted existing custom plugin to Swift language:

(located under Plugins/CustomPluginInSwift.swift)

import Foundation

class Cu         


        

Answer 1

CDVPlugin not found

When you created swift file 1st time, Xcode asks you to generate

<your app name>-Bridging-Header.h header with empty content:

//
//  Use this file to import your target's public headers that you would like to expose to Swift.
//

In this header add:

#import <Cordova/CDVPlugin.h>

After that clean your project. If you don't have this header - create it.

---

CDVPlugin class CustomPluginInSwift (pluginName: CustomPluginInSwift) does not exist

[Step 1]

Right, because Swift uses _TtC (Type To Class) prefix and class index with following template:

_TtC8<AppName><index#><PluginName>   

How to know what is proper index?

[Step 2]

When you initiate instance of CustomPluginInSwift class, like:

var temp:CustomPluginInSwift = CustomPluginInSwift()

, Swift will add new class name to <AppName>-Swift.h header. The problem is that this header you can't see in your project.

How to find it?

• Go to xCode -> Window -> Organazer -> "Project Tabs"
• Select your project
• copy "Derived Data" path (for me: ~/Library/Developer/Xcode/DerivedData/<AppName>-hbgwavxfqvhwxzagxhgzjvsdrkjk)
• Go to console and run cd ~/Library/Developer/Xcode/DerivedData/<AppName>-hbgwavxfqvhwxzagxhgzjvsdrkjk
• run after: cd Build/Intermediates/<App name>.build/Debug-iphoneos/<App name>.build/DerivedSources/

You can find file named: <App name>-Swift.h there with following content:

/* ... */

SWIFT_CLASS("_TtC8Wanameet14CustomPluginInSwift")
@interface CustomPluginInSwift : CDVPlugin
- (void)getSettings:(CDVInvokedUrlCommand *)command;
- (instancetype)initWithWebView:(UIWebView *)theWebView OBJC_DESIGNATED_INITIALIZER;
- (instancetype)init OBJC_DESIGNATED_INITIALIZER;
@end

/* ... */

So we got proper name: _TtC8Wanameet14CustomPluginInSwift

[Step 3]

Now, go to config.xml and change from:

<feature name="CustomPluginInSwift">
    <param name="ios-package" value="CustomPluginInSwift" />
</feature>

to:

<feature name="MeeterCalendar">
    <param name="ios-package" value="_TtC8Wanameet14CustomPluginInSwift" />
</feature>

---

Thats all,

Hope it will save time,

tested on cordova 3.5 + xCode6.1

---

examples

Consider you have Plugins folder in your project (generated by Cordova).

We create New swift file MyPlugin.swift with following content:

@objc(HWPMyPlugin) class MyPlugin : CDVPlugin { // see @tsubik answer
 /* ... */
}

method example where we parse javascript request and immediately return answer:

func someMethod(command: CDVInvokedUrlCommand){
    
    println("MyPlugin :: someMethod is called")
    
    let callbackId:String = command.callbackId
    
    var obj:AnyObject = command.arguments[0] as AnyObject!
    
    var eventStructure:AnyObject = obj["eventStructure"]
    var eventId:String = eventStructure["_id"] as AnyObject! as String        
    
    println("MyPlugin :: someMethod :: _id:  \(eventId) ")
        
    self.commandDelegate.runInBackground({
        // 'jw' is some class          
        var data:NSData = jw.toJson()
        var str:String = jw.toJsonString(data)
        
        
        var obj:JSONObject = jw.getJSONObjectFromNSData(data)
        println("sampleList as String: \(str)")
        
        var pluginResult:CDVPluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAsDictionary: obj)
        self.commandDelegate.sendPluginResult(pluginResult, callbackId:command.callbackId)
    })

}

method example where we return empty callabck and after some time return answer:

I used a lot this method form when you try to fetch some data on native side by async way:

protocol AccountLoaderListenerItf {
   func onAccountsDone(data:NSData)
} 

@objc(HWPMyPlugin) class MyPlugin : CDVPlugin, AccountLoaderListenerItf { 
 
  var mCalendarAccountsCallbackContext:String?

  
func getCalendarAccounts( command: CDVInvokedUrlCommand ){
    println("MyPlugin :: getCalendarAccounts is called")
    
    self.mCalendarAccountsCallbackContext = command.callbackId
    
    self.commandDelegate.runInBackground({            
        
        var all:AccountLoaderListenerItf = self
        
        var accounts = MyAccounts(accLoader: all)
        
        accounts.populateFromCalendars()            
        
        var pluginResult:CDVPluginResult = CDVPluginResult(status:CDVCommandStatus_NO_RESULT)
        pluginResult.setKeepCallbackAsBool(true)
        self.commandDelegate.sendPluginResult(pluginResult, callbackId:command.callbackId)            
    })
} // func

 /* .... */

func onAccountsDone(data:NSData){
        if self.mCalendarAccountsCallbackContext != nil {            
            
            var list:JSONArray = WmUtils.getJSONArrayFromNSData(data) // dummy data
            var pluginResult:CDVPluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAsArray: list)
            pluginResult.setKeepCallbackAsBool(false)
            self.commandDelegate.sendPluginResult(pluginResult, callbackId:self.mCalendarAccountsCallbackContext)
        }
    }


}

Answer 2

As is mentioned you have to add a bridging-header.h file which contains

#import <Cordova/CDV.h>

Also you need to add the bridging header's path in XCode project properties->Build Settings->Objective-C Bridging Header. For example:

your-app-name/plugins/com.plugin.example/bridging-header.h

Additionally, in order for Objective-C to see the same plugin class name, you need to add an @objc mapping to the class declaration. It can be the same as the swift class name itself, or something different. In this example, "HWPCustomPluginInSwift" will be what Objective-C (and Javascript) will end up seeing:

@objc(HWPCustomPluginInSwift) class CustomPluginInSwift : CDVPlugin {

and then your feature node in config.xml file should look like this:

<feature name="CustomPluginInSwift">
    <param name="ios-package" value="HWPCustomPluginInSwift" />
</feature>