Cordova Mock Interview Questions

If you’re preparing for an interview for the role of Hybrid Mobile App Developer focused on Apache Cordova, it’s important to be familiar with various aspects of the framework, from basic concepts to more advanced topics. Below are some common interview questions along with their detailed answers to help you prepare for the role of Hybrid Mobile Application Developer.

Apache Cordova is an open-source mobile development framework that allows developers to build mobile applications using HTML, CSS, and JavaScript. Cordova wraps the web application in a native container, which can then be deployed to various mobile platforms such as iOS, Android, Windows, and more. This approach provides a way to create cross-platform applications without needing to write platform-specific code.

• Apache Cordova was created by Nitobi.
• Adobe Systems purchased Nitobi in 2011, rebranded it as PhoneGap, and later released an open-source version of the software called Cordova.
• Cordova can be used by any web developer to access native capabilities of mobile devices like GPS, Camera, Bluetooth etc.

2. How does Cordova work?

Cordova works by embedding a WebView into a native application.

• WebView is a native container that is available in most of the mobile devices.
• This WebView displays the HTML, CSS, and JavaScript code of our web application.

Cordova provides a JavaScript API that allows a web app to interact with native device features like the camera, GPS, and contacts. The Cordova native shell acts as a bridge between the JavaScript code and the native APIs, enabling the web app to use device features as if it were a native app.

3. What are Cordova plugins, and how do you use them?

Cordova plugins are JavaScript APIs that provide access to native device features. They act as a bridge between the Cordova WebView and the native code. We can add plugins to a Cordova project using the command-line interface (CLI) with the following command:

cordova plugin add <plugin-id>

We can find available plugins in the Cordova Plugin Registry or on npm. To use a plugin, we generally call the provided JavaScript functions, which will internally invoke the corresponding native functionality.

4. How do you add a platform to a Cordova project?

We can add a platform to your Cordova project using the CLI. For example, to add the Android platform, we will run:

cordova platform add android

To add the iOS platform, use:

cordova platform add ios

Each platform has its own specific requirements and may need additional setup or dependencies.

5. What are some common Cordova CLI commands?

Some common Cordova CLI commands include:

• cordova create <path> <id> <name>: Creates a new Cordova project.
• cordova platform add <platform>: Adds a platform to the project.
• cordova plugin add <plugin-id>: Adds a plugin to the project.
• cordova build: Builds the project for all added platforms.
• cordova run <platform>: Runs the project on the specified platform.
• cordova serve: Serves the app using a local web server for testing.

6. How do you handle device-specific features in Cordova?

Device-specific features in Cordova are handled using plugins. Each plugin provides JavaScript methods that correspond to native functionalities. For example, to access the device’s camera, you would use the Cordova Camera plugin. The plugin’s documentation will specify the available methods and their usage.

navigator.camera.getPicture(onSuccess, onFail, { quality: 50, destinationType: Camera.DestinationType.DATA_URL });

function onSuccess(imageData) {
    var image = document.getElementById('myImage');
    image.src = "data:image/jpeg;base64," + imageData;
}

function onFail(message) {
    alert('Failed because: ' + message);
}

7. What are the differences between Cordova and other frameworks like Ionic or React Native?

Cordova: Provides a way to build cross-platform mobile apps using web technologies (HTML, CSS, JavaScript) with access to native features through plugins. It primarily wraps a web application in a native container.

Ionic: Built on top of Cordova, Ionic is a UI framework that provides a library of pre-designed components and themes for building hybrid mobile applications. It aims to provide a more consistent and appealing UI experience.

React Native: Uses JavaScript and React to build mobile apps, but unlike Cordova, it compiles to native code, which can offer better performance and a more native-like user experience. React Native does not use a WebView but interacts directly with native components.

8. What are some common issues faced when using Cordova?

Some common issues include:

• Performance: Hybrid apps can sometimes suffer from performance issues compared to fully native apps, especially with complex UI or heavy computations.
• Plugin Compatibility: Plugins may not always be up-to-date or may have compatibility issues with different versions of Cordova or platforms.
• Debugging: Debugging can be more challenging compared to native apps, especially when dealing with the bridge between JavaScript and native code.
• UI Consistency: Achieving a consistent look and feel across different platforms can be difficult with Cordova, as it relies on WebView rendering.

9. How do you debug a Cordova application?

Browser Debugging: Use the browser’s developer tools to debug the web portion of your app. Most browsers have tools for inspecting HTML, CSS, and JavaScript.

Remote Debugging: For mobile devices, use remote debugging tools such as Chrome DevTools for Android or Safari Web Inspector for iOS. Connect your device via USB and use the developer tools to inspect and debug.

Logs and Console: Use console.log statements to output debug information to the device’s log. You can view these logs using tools like adb logcat for Android or Xcode’s console for iOS.

10. How do you handle updates and versioning in Cordova projects?

• Plugins: Keep plugins updated by regularly checking for new versions and using the cordova plugin update command.
• Platforms: Update platforms using cordova platform update <platform>. Ensure compatibility with the latest Cordova version and other dependencies.
• Project Versioning: Manage your app’s version number in the config.xml file. Update the version attribute to reflect new versions.

By preparing for these questions, you’ll have a solid understanding of Cordova and be well-prepared for your interview.