Creating Plugins

The Smart WebView plugin architecture allows you to extend the application’s native capabilities. Follow these steps to create your own plugin.

1. Create the Plugin Class

1. Create a new Java class inside the app/src/main/java/mgks/os/swv/plugins/ directory.

2. Make your class implement the PluginInterface.

   package mgks.os.swv.plugins;
   
   import android.app.Activity;
   import android.content.Intent;
   import android.webkit.WebView;
   import androidx.annotation.NonNull;
   import java.util.Map;
   
   import mgks.os.swv.Functions;
   import mgks.os.swv.PluginInterface;
   
   public class MyCustomPlugin implements PluginInterface {
   
       private Activity activity;
       private WebView webView;
   
       @Override
       public void initialize(Activity activity, WebView webView, Functions functions, Map<String, Object> config) {
           this.activity = activity;
           this.webView = webView;
           // Initialization logic here...
       }
   
       @Override
       public String getPluginName() {
           return "MyCustomPlugin"; // Must be a unique name
       }
   
       @Override
       public void onActivityResult(int requestCode, int resultCode, Intent data) {
           // Handle results from activities started by this plugin
       }
   
       @Override
       public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
           // Handle results from permission requests
       }
   
       @Override
       public boolean shouldOverrideUrlLoading(WebView view, String url) {
           // Example: Handle a custom URL scheme
           if (url.startsWith("myplugin://dosomething")) {
               // Perform a native action
               return true; // We've handled the URL
           }
           return false; // Let other plugins or the default handler process it
       }
   
       @Override
       public void onPageStarted(String url) { }
   
       @Override
       public void onPageFinished(String url) {
           // Logic to run after a page loads, like injecting JS
       }
   
       @Override
       public void onDestroy() {
           // Clean up resources
       }
   
       @Override
       public void evaluateJavascript(String script) {
           if (webView != null) {
               webView.evaluateJavascript(script, null);
           }
       }
   }
   

2. Implement Self-Registration

Add a static initializer block to your plugin class. This automatically registers an instance of your plugin with the PluginManager when the app starts.

public class MyCustomPlugin implements PluginInterface {

    // ... (existing methods) ...

    // Static initializer block for self-registration
    static {
        // Provide a default configuration for your plugin
        Map<String, Object> defaultConfig = new HashMap<>();
        defaultConfig.put("apiKey", "DEFAULT_KEY");
        defaultConfig.put("enabled", true);

        // Register the plugin with the manager
        PluginManager.registerPlugin(new MyCustomPlugin(), defaultConfig);
    }

    // ... (rest of the class) ...
}

3. Implement Plugin Logic

Fill in the methods from the PluginInterface to add your native functionality. You can start activities, request permissions, handle URL loading, and communicate with the WebView.

4. Communicate with JavaScript

You have two primary ways to trigger native code from your web content:

• Custom URL Schemes: Your web page can navigate to a unique URL like myplugin://show-dialog?title=Hello. Your plugin intercepts this in shouldOverrideUrlLoading, parses the URL, and performs the native action. This is simple but less flexible.
• JavaScript Interface: Add a dedicated class with methods annotated with @JavascriptInterface. Add an instance of this interface to the WebView in your plugin’s initialize method (e.g., webView.addJavascriptInterface(new MyJSInterface(), "MyPluginAndroid")). This allows your JavaScript to directly call native methods (e.g., window.MyPluginAndroid.performAction("data")), which is more powerful and flexible.

To send data from native back to JavaScript, use the evaluateJavascript() method.

5. Enable and Test

1. Enable the Plugin: Ensure your plugin is enabled in the ASWP_PLUGIN_SETTINGS map in SmartWebView.java.

   put("MyCustomPlugin", true);
   

2. Test with Playground: Use the Playground.java class to test your plugin in a sandboxed environment. You can run diagnostic checks and add buttons to the demo UI to trigger your plugin’s features.