android-javascript：通过添加javascriptinterface使用原型将对象注入Webview

Question

Im using addJavaScriptInterface to inject my object "myObj" into webview. Here part of code

private void portalInit() {
        CookieSyncManager.createInstance(this);
        CookieSyncManager.getInstance().startSync();
        wv.getSettings().setJavaScriptEnabled(true);
        wv.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        wv.getSettings().setAllowContentAccess(true);
        wv.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onConsoleMessage(ConsoleMessage cm) {
                Log.d("From JavaScript",
                        cm.message() + " -- From line " + cm.lineNumber()
                                + " of " + cm.sourceId());
                return true;
            }
        });

        wv.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }
        });

        wv.addJavascriptInterface(new myObj(this, wv), "myOBJ"); 
        wv.loadUrl("http://dl.dropbox.com/u/16515769/gradient.html");
        wv.requestFocus(View.FOCUS_DOWN);

    }

And i have HTML page that i can't change, where onload doing some crazy stuff

<script>
function f1(){
    this.do1 = function(par){
        console.log("1: "+par);
    };
    this.do2 = function(num){
        console.log("2: "+num);
    };
}
function f2(){
    this.do3 = function(par){
        console.log("3: "+par);
    };
    this.do4 = function(num){
        console.log("4: "+num);
    };
}
var myobj;
var myobj_e = myOBJ;
f1.prototype = myobj_e;
f2.prototype = new f1();
myobj = new f2();

function keydown(e){
    var key  = e.keyCode || e.which;
    switch(key){
        case 13:
            myobj.Debug("turn it on!!!!");
        break;
        case 27:
            myobj.do1("turn it on!!!!");
        break;
        case 49:
            myobj.do4("fsdfd")
        break;
    }
}

this constuction work fine in our hardware device where object injected to real webkit browser, but not work in android webview, and accesing to myobj.Debug post error in logcat (Javascript error)

Uncaught ReferenceError: NPMethod called on non-NPObject -- From line 36 of http://dl.dropbox.com/u/16515769/gradient.html

Note: if i call in javascript myOBJ.Debug("something"); it work fine, so i think that part "f1.prototype = myobj_e;" not working.

I will be very glad to get some help.

Answer 1

So i find a workaround. Its not a solution, but i cant do it in other way.

We can not change object that was added to webview by addJavascriptInterface in webpage side. So I need to make my own object, which will retranslate calls to interface. I injected javascript onPageStarted and changeed object name to myOBJ_tmp

  wv.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
        @Override
        public void onPageStarted (WebView view, String url, Bitmap favicon){
            String script= "javascript:var func_list = ['Debug'];";
                   script+="var myOBJ = {};"
                   script+="func_list.map(function(id){"
                   script+="myOBJ[id]= function() {"
                   script+="try{return myOBJ_tmp[id].apply(myOBJ_tmp, arguments);}"
                   script+="catch(e) { console.log('ERROR: ' + e + ', method ' + id);"
                   script+="return false;}}})"
            view.loadUrl(script);
        }
    });

Hope this will help somebody.