Android WebViewAssetLoader support

[ccoltos]

Is there any intention to add support for WebViewAssetLoader on Android?

Current issue:

JavaScript cannot fetch("file://android_asset/...") due to security reasons and requires a special assets loaded handling described in here: https://developer.android.com/reference/androidx/webkit/WebViewAssetLoader.

This will allow any Web App hosted inside the WebView to access any type of bundled asset resource (from android/app/src/main/assets) through JS fetch/XMLHttpRequest calls.

Solution Suggestion:

Add a property allowAssetsLoader to the WebView, that will intercept on demand the urls and will interpret the custom assets scheme: https://appassets.androidplatform.net/assets/

android/src/main/java/com/reactnativecommunity/RNCWebViewClient.java:

@Nullable
@Override
    public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
        if(!allowAssetsLoader) {
            return super.shouldInterceptRequest(view, request);
        }

        if(assetLoader == null) {
            RNCWebView reactWebView = (RNCWebView) view;
            assetLoader = new WebViewAssetLoader.Builder()
                    .addPathHandler("/assets/", new WebViewAssetLoader.AssetsPathHandler(reactWebView.getReactApplicationContext()))
                    .build();
        }

        return assetLoader.shouldInterceptRequest(request.getUrl());
    }

[birdofpreyru]

Hey @ccoltos 👋 I'll sure accept PR for this 😃