在android和ios中加载并执行脚本

Question

My requirements:

• This should work in Android and iOS
• I want to load a script (could be Javascript or Lua or any other scripting language) from a file (not necessarily over the network)
• The script should run in a background thread and be able to post to the UI thread
• I want to use the same script in iOS and Android, so that I can reuse the script code both in Android and iOS app

What are my options?

Answer 1

WebView Android with Javascript Enabled

SFWebView i think in iOS also support Javascript.

Not sure that you can use it in background thread as Android Webview will only runs on UI thread

Answer 2

Answer: 1. You MUST load the HTML into string:

private String readHtml(String remoteUrl) {
String out = "";
BufferedReader in = null;
try {
    URL url = new URL(remoteUrl);
    in = new BufferedReader(new InputStreamReader(url.openStream()));
    String str;
    while ((str = in.readLine()) != null) {
        out += str;
    }
} catch (MalformedURLException e) { 
} catch (IOException e) { 
} finally {
    if (in != null) {
        try {
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
return out;
}

2. Load WebView with base URL:

     String html = readHtml("Your Web URL"); mWebView.loadDataWithBaseURL("file:///android_asset/", html, "text/html", "utf-8", ""); 

In this particular case you should have all .js files you want to use on the page to reside somewhere under "assets" folder of project. For example:

 /MyProject/assets/jquery.min.js

3. In your remote html page you have to load .js and .css files that reside in your application like:

the same applies to all other local resources like images, etc. their path has to start with

file:///android_asset/

A WebView would first load the raw HTML you have provided as string, then pick .js, .css and other local resourses and then would load remote content.

Answer 3

In android, While loading the page into webview. Intercept the script call.

public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
 if ( url.endsWith("script.js") ) {
    AssetFileDescriptor fileDescriptor = assetManager.openFd("script.js");
    FileInputStream stream = fileDescriptor.createInputStream();
    return new WebResourceResponse("text/javascript","UTF-8",stream);
 }
}

Webview runs on ui thread. I am not sure that there is way to load webresources from background threads.