How do convert native apps to react native?

In 2015, React Native was released as an open-source platform. It doesn’t need HTML or CSS. Rather, the react native developers write native code in Java or Objective C. The ease of complexity and scalability that the framework holds is matchless and the app provides an improved user experience. But some software development companies still think that native apps are best for app development. In most of situations, businessmen are convinced with respect to the technology stack that these organizations support, thinking about their experience. But, they wind up saving more if the prerequisite of the Android and iOS application isn’t at par with the development. Then, which is the way to go?

Here are two ways to develop a highly reliable android and iOS app- 

• Build a native app using React Native
• Convert existing app to React Native

In case you are putting resources into the development of a Native application, you need not spare one more big budget. Here we’ll guide you on how to convert Native android or ios apps to react native. Before digging into it, let’s see the things to consider while converting native android and ios apps into React Native.

Things to consider while converting native android and ios apps into React Native-

Reducing the number of code to be written is the most efficient way to convert native Android and iOS apps into React Native. If there are lots of changes to be made in the extent of native Android and iOS apps, it will be a better idea to develop a new app using React native. But it limits the requirements and the type of the application. Hence, if you are looking to replace Native Android and iOS applications into React Native, below are some of the aspects that you should consider:

1. Update libraries to the latest versions-

When you develop an app using react native, it is always advisable to switch to the new and advanced technology stacks. Here the tech stack includes frameworks, tools, libraries, and databases. If you’re using other versions, it is advisable to check for the android version. Lots of features are available to use when you choose the latest version of React Native, that includes auto-linking, Android migration, lean core, accessibility, and so on. If you find any third-party app interrupting with the app with the build.Gradle, you can include post-install script such as-

    // package.json

    {

        “scripts”: {

            “bootstrap”: “yarn install && yarn run post-install”

            “post-install”: “./scripts/postInstall.sh”,

        }

    }

Also, it is recommended to include Hermes to enhance the speed of your app.

    project.ext.react = [

        entryFile: “index.android.js”,

        enableHermes: true,  // clean and rebuild if changing

    ]

2. Execute custom native modules-

Just making a module file isn’t sufficient. You need to register a module before using a native module. And you need to build another Java class for the creation and registration of this module. After a successful import of the file, the last step to complete the registration process is to initiate DevicePackage class. To achieve this, you need to edit the file by adding the below code-

new DevicePackage() //Add your package here

In the JavaScript file, you can use the module methods through,

NativeModules..

3. Adding assets to the React Native app-

There are various assets in an application- launcher icons, push notification icons, and custom fonts. These components are to improve the user satisfaction rate. And also it is important to make the react native app as user-friendly as possible. In this way, you can change the appearance of the icon of debugging the app. Also, push notification is an important feature of an app when it comes to bringing a user back to the application. The image that you select for the push notification logo should have a transparent background for a better view. Apart from this, images, icons, and font also play an important role in the great view of the app. Therefore, you can develop functionality for fetching the necessary font from the rich font family.

    val fontTypefaces = HashMap()

    fun downloadFonts(fontName: String, font: GoogleFonts) {

        val handlerThread = HandlerThread(“fonts”)

        handlerThread.start()

        val handler = Handler(handlerThread.looper)

        val builder = QueryBuilder(font.family)

        if(font.italic == 1) {

            builder.italic()

        }

        if(font.weight > 0) {

            builder.weight(font.weight)

        }

        val request = FontRequest(

            “com.google.android.gms.fonts”,

            “com.google.android.gms”,

            builder.build(),

            R.array.com_google_android_gms_fonts_certs)

        val callback = object : FontsContractCompat.FontRequestCallback() {

            override fun onTypefaceRetrieved(typeface: Typeface) {

            ReactFontManager.getInstance().setTypeface(fontName, typeface.style, typeface)

            fontTypefaces[fontName] = typeface

        }

        override fun onTypefaceRequestFailed(reason: Int) {

        }

        FontsContractCompat

            .requestFont(context, request, callback, handler)

    }

Also, you can load the fonts by using ReactFontManager. You just need to call the font using React Native is the same way as below-

    const styles = {

        proximanovaText: {

            fontFamily: ‘Proxima Nova’,

        },

    };

4. UI Components-

The best feature of using React Native is that programmers can reuse components to fit and develop applications. React-Native uses pixel density to ensure the layout resolution is at standard with Android. This results in, you don’t need to consider the issues associated with the style misalignment between two platforms. Android and iOS have differences with regard to interfaces as well as design standards. Subsequently, you need to follow material design rules to look through the default components.

How to add React Native to your existing Native android and ios application?

The best way to approach a React Native app is to start from scratch. Also, you can use it when you want to integrate a user flow to the extent of native apps. You can simply integrate react native to your existing apps when you know the appropriate components and steps.

Important steps to know before integration-

• Plan dependencies related to React Native and work on the directory structure
• Build react native components in Javascript
• Install RCTRootView to the iOS app and ReactRootView to Android App, that will work as a container for react native
• Start with the react native server and execute the application.
• Validate that your React Native components are functioning as expected.

Requirements for Integration-

1. Prepare a directory structure in place-

To provide a seamless user experience, you can have a new folder for react native projects. After this, you can copy the existing code to the iOS or android folder.

 

2. Set up javascript dependencies-

Go to the root directory. Check the installation of the yarn package manager. Here you will be building a new package with-

{

  “name”: “ReactNativeApp”,

  “version”: “0.60”,

  “private”: true,

  “scripts”: {

“start”: “yarn react-native start”

  }

}

Install react-native packages and navigate to new packages. Yarn will create a new folder, which will have all the dependencies about Javascript for building a project.

How to integrate react native?

1. Maven Configuration-

The first step of configuring maven in to add react native and Javascript dependencies to the library build Gradle file When you want to ensure that you are on the appropriate react native version, you can replace plus sign with the actual version of it. Check that you add an entry for the Javascript maven directories and react-native to ‘allprojects’. You can also cross-check for the final path.

 

2. Enable autolinking of native modules –

For autolinking, You need to make an entry to settings.gradle. Then, add that entry to app/build.gradle.

 

3. Configuration of the permissions-

Check your internet permission. You can take a look in Android.Manifest.xml. If according to the user flow, you need access to DevSettingActivity, you can add activity to AndroidManifest.xml.

4. ClearText traffic-

If your android version is over 9, you’ll notice that cleartext traffic is disabled. It will prevent the app from connecting to Metro builder. To allow the allow the connection, you can apply code use cleartext traffic to AndroidManifest.xml.

5. Integration of code-

Integrating code needs programmers to follow particular steps-

• Build an index.js file.
• Include React Native code
• Get permission for the development error overlay
• RenderRender JS component

By default, the dev menu will be activated but not in emulators. Subsequently, you need to use ctrl + M to execute JavaScript code for testing.

6. Testing-

Just like other code and apps, you need to test integration to check whether the react native app is working as expected. You can use Metro builder to build index.budle.

Run the packager- Run $ yarn start in the root directory.

Run the App- While running the app, react native should be able to load the javascript from a server and show desired results. 

Final Words-

React native is popular and cost-saving too. Its community is continuously expanding, meaning that the react native can deliver better results in the future. It will be a new experience when you upgrade the native app to react native. The above details will surely help you convert the native app to react native apps. If you’re facing any difficulty while implementing this, consult with Solace experts. We are here to help you through consultation and development of react native apps. You can hire react native developers of the Solace team for effective app development. Connect with Solace and get a free quote for react native development. We will be happy to help you.

The post How to convert your Native Android & iOS app to React Native? first appeared on Blog.