Fix rnpm script #53

src/scripts/prelink.js

 var fs = require('fs');
+
 var MANIFEST_PATH = process.cwd() + '/android/app/src/main/AndroidManifest.xml';
+var PACKAGE_JSON = process.cwd() + '/package.json';
+
+var hasNecessaryFile = fs.existsSync(MANIFEST_PATH) && fs.existsSync(MANIFEST_PATH);
+
+if (!hasNecessaryFile) {
+  throw 'RNFetchBlob could not found link Android automatically, some files could not be found.'
+}
+
+var package = JSON.parse(fs.readFileSync(PACKAGE_JSON));
+var APP_NAME = package.name;
+var APPLICATION_MAIN = process.cwd() + '/android/app/src/main/java/com/' + APP_NAME.toLocaleLowerCase() + '/MainApplication.java';
+
+if(!fs.existsSync(APPLICATION_MAIN)) {
+  throw 'RNFetchBlob could not found link Android automatically, MainApplication.java not found in path : ' + APPLICATION_MAIN
+}
+
+var VERSION = checkVersion();
+console.log('RNFetchBlob detected app version .. ' + VERSION);
 
+if(VERSION >= 0.29) {
+  console.log('RNFetchBlob patching MainApplication.java .. ');
+  var main = fs.readFileSync(APPLICATION_MAIN);
+  if(String(main).match('new RNFetchBlobPackage()') !== null) {
+    console.log('skipped');
+    return
+  }
+  main = String(main).replace('new MainReactPackage()', 'new RNFetchBlobPackage(),\n           new MainReactPackage()');
+  main = String(main).replace('import com.facebook.react.ReactApplication;', 'import com.facebook.react.ReactApplication;\nimport com.RNFetchBlob.RNFetchBlobPackage;')
+  fs.writeFileSync(APPLICATION_MAIN, main);
+  console.log('RNFetchBlob patching MainApplication.java .. ok')
+
+}
+
+// set file access permission for Android < 6.0
 fs.readFile(MANIFEST_PATH, function(err, data) {
 
   if(err)
     console.log('failed to locate AndroidManifest.xml file, you may have to add file access permission manually.');
   else {
+
+    console.log('RNFetchBlob patching AndroidManifest.xml .. ');
     // append fs permission
     data = String(data).replace(
       '<uses-permission android:name="android.permission.INTERNET" />',
       '<category android:name="android.intent.category.LAUNCHER" />\n     <action android:name="android.intent.action.DOWNLOAD_COMPLETE"/>'
     )
     fs.writeFileSync(MANIFEST_PATH, data);
+    console.log('RNFetchBlob patching AndroidManifest.xml .. ok');
 
   }
 
 })
+
+function checkVersion() {
+  console.log('RNFetchBlob checking app version ..');
+  return parseFloat(/\d\.\d+(?=\.)/.exec(package.dependencies['react-native']));
+}