WebViewのjavascriptからViewControllerのfunctionを呼び出す方法

Problem

WebViewにロードしたjavascriptから、ViewControllerのfunctionを呼び出したい

Solution

サンプルコード

• サンプルコードで使用しているライブラリ
• SwiftFilePath: NSFileManagerのWrapperなので、必要ではない

WebViewEvent.js

open("native://anchorClicked?anchorUrl=" + anchorUrl)

WebViewController.swift

class WebViewController: UIViewController, UIWebViewDelegate {

  @IBOutlet weak var webView: UIWebView!

...(省略)...

  func getJavascriptString() -> String {
    let path = NSBundle.mainBundle().pathForResource("WebViewEvent", ofType: "js")!
    return Path(path).readString()!
  }

  func webViewDidFinishLoad(webView: UIWebView) {
    self.webView.stringByEvaluatingJavaScriptFromString(getJavascriptString())
  }

  func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {

    var url = request.URL!.standardizedURL
    if (url?.scheme == "native") {
      if url?.host == "anchorClicked" {
        let queryStrings = getQueryStrings(url!.query)
        anchorClicked(queryString)
      }
    }
  }

  func anchorClicked(queryString: [String: String]) {
    println(queryString["anchorUrl"])
  }
  
  func getQueryStrings(query: String?) -> [String: String] {
    var queryStrings = [String: String]()
    if let query = query {
      for qs in query.componentsSeparatedByString("&") {
        // Get the parameter name
        let key = qs.componentsSeparatedByString("=")[0]
        // Get the parameter value
        var value = qs.componentsSeparatedByString("=")[1]
        value = value.stringByReplacingOccurrencesOfString("+", withString: " ")
        value = value.stringByReplacingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!
        
        queryStrings[key] = value
      }
    }
    return queryStrings
  }
  
}