Android network request best practice
Improper handling of this scenario is an instance of bad user experience. This could make you loose out on a whole lot of users. One solution to this is not far off. With the ViewModel as part of the architecture components released by Google in , you can be comfortable about the orientation change of your app without losing data in it.
The ViewModel is designed to store and manage UI-related data in a lifecycle conscious way. With it, your data can survive configuration changes. To use it, you require dependencies: Add this to your project build. And this to your app build. And then you can connect it to your data sources to fetch data.
Below, is an image that shows the lifecycle of an Activity as compared to that of a ViewModel. They hold temporary data that survives when your phone is rotated. Another solution to consider is persisting your data in the database after it has been fetched from a remote source so that when the phone is rotated, data can quickly be gotten from the DB instead of having to fetch again.
Another bad user experience is in irregular freezing of an app. Irregular in the sense that it is, as a result, one carelessness or the other. This could be as a result of performing tasks on the wrong thread. Operations that take a long time to finish usually freeze our app and as such need to be handled outside of the main thread. A typical example of a background task is a database operation. A snippet for handling this in the background can be this:. This snippet sets aside one thread to perform the operation in the background.
If you use RxJava , you can equally take advantage of the schedulers that come with the library like this:. In the snippet above, the subscription is done on another thread while the result is being observed in the main thread. If the long-running tasks will live after you close your app, you should consider using a service, particularly an IntentService. This service naturally runs on the background thread and handles tasks in form of Intents.
Below is an example of an IntentService:. In Android, the word compatibility points to two options: As Android developers, we just have to worry about the first - app compatibility. Talking about device compatibility, only devices that are Android compatible include Google Play Store which in turn accepts our app.
So as app developers, we have no role to play here at least for now. This aspect focuses on a UI that scales i. There are many devices with different screen sizes and densities. There are principles to be applied to achieve this feat.
Designing Android apps to handle slow network speed
Android provides a framework in which we can provide configuration-specific app resources such as different XML layouts for different screen sizes. Android then loads the appropriate resources based on the current device configuration. If you have intentions of supporting a tablet, you should consider creating an alternative layout. In our own case here, we chose the smallest width qualifier and set the smallest screen width to dp.
This means that only screens with a minimum width of dp can use this alternative layout. This layout is definitely for tablets. You can create layouts based on heights, orientation, and general sizes. Creating alternative layouts can be minimized if you use a very flexible layout as ConstraintLayout, and you reduce hard coding of view sizes.
When assigning a width and height to a view, using a direct size, say 20dp might have a negative design effect on contrasting devices. Remember the device you use for preview is not the only device that exists!
- Perform network operations overview?
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Just as we create alternative layouts, we also need to create alternative drawable image files if you are going for the traditional. But using vector drawables are recommended because of scalability. To use them, make sure there are enabled in your app build. Then, you store your vector file usually ending with.
Another aspect you should take note of is potential support for multiple languages.
what are best practices for performing network operations in Android? - Stack Overflow
To achieve this, you have to store all your strings in the strings. This gives room for easy translation at any point in time. Security could easily be one of the most neglected areas when building apps because it is large in scope and seen by many as impossible to perfect. Google, as usual, has acted quickly to release features that significantly reduce the frequency of security issues.
Some of which include:. However, some security vulnerabilities are outside their control at least at the moment. There is still some work to be done. Most times, our apps need to communicate with APIs and backend services to fetch data or send data. This should be done in a secure manner. For this reason, The network security configuration was introduced to ensure adequate validation of the servers our apps intend to communicate with. When we talk about secure backend services, we won't go too far because have such services readily available at your beck and call, thanks to Auth0.
Auth0 is a company that provides identity management solutions for our apps. If you are building a social app or anything related that requires authentication and user management, you could use the service provided to us by Auth0 to manage our identities while you focus on other functionalities. Auth0 makes use of secure protocols such as OAuth2. The OAuth2. It is a protocol that gives a user access to resources on a server without exposing the identity.
Below is a generic workflow of the protocol. Integrating this service is quite easy. First, create a new Android project by following the usual wizard. You can download a stable version of Android studio here. Go ahead to add the Auth0 library in your app build.
This is the latest Android Lock library released recently with some bug fixes. Usually, the library needs to connect to another server and so we need the internet permission. Go to your AndroidManifest.
Android Networking Tutorial: Getting Started
Next, you create an account at Auth0. It is free and easy to setup. When you get to your dashboard, create a new application by clicking the Create Application button. Insert a name for the application and choose native as its type.
Here is how a newly created application looks. After this, we need to configure our callbacks. Go to the settings tab of your newly created application and add the URL:. Next, we copy the credentials of your Auth0 application to strings. You also have to configure your manifest holders with the domain details.
Open your app build. Notice that we still maintained the same scheme - demo as we used in the callback URL. For Android, Auth0 offers both the browser-based and native logins. The browser login is highly recommended and you can see why that is so here. For this sample, we will use the browser-based login.
We then begin our authentication like this:. Here we initialized the Auth0 object with the app context. This is because we have already provided the details in the AndroidManifest. We also set it to be ODI comformant. And we used the same scheme as we used in our callback URL and manifest holders. If you are connected on WiFi, you can assume that your connection would probably be fast, but this is not true in all cases, your WiFi network connection might go down temporarily or just reduce in speed.
Network API will not indicate if your internet connection has dropped in the middle of your remote call. To measure the quality of your network speed for proper handling, you need to download some file from the internet and calculate how long it took vs number of bytes. So we fetch the required image file and calculate how long it took to download the image by subtracting the end time from start time.
The duration of the download definitely depends on the size of the file you are downloading, a file of kb should not take more than 6 secs to download under a fast internet connection. Steps to be taken: Steps to use the library: In your onCreate, get the instance of the connection class manager and device bandwidth sampler. Here, we use OkHttp to make request for the image, start sampling before the request is made and stop sampling after request is completed and get the quality of the connection.
If request fails, we stop sampling and retry 10x times until we get the quality. This Connection library provides different connection qualities, If the quality of your connection cannot be accurately found, it returns Unknown. The single-thread model ensures that the UI is not modified by different threads at the same time. So, if we have to update the ImageView with an image from the network, the worker thread will perform the network operation in a separate thread, while the ImageView will be updated by the UI thread. This makes sure that the operations are thread-safe, with the UI thread providing the necessary synchronization.
It also helps that the UI thread is always non-blocking, because the actual task happens in the background by the worker thread. For example, playing music or downloading content in the background can be done well with services. If you need to perform work outside of your main thread while the user is interacting with your app, you are better off using a networking library such as AsyncTask or Volley. Performing tasks in worker threads is great, but as your app starts to perform complex network operations, worker threads can get difficult to maintain.
Android does have a resource to help handle network calls asynchronously. AsyncTask is a module that allows us to perform asynchronous work on the user interface. The UI thread gets these results and updates the user interface accordingly. I also pass the access token in the request header and the campaign ID in the body. If you look at the code, java. In the example above, we also make use of the application context to pop up toast messages, but AsyncTasks can be defined as inner classes in activities if they are small enough, avoiding the need for the Context property.
A generic type is a generic class or interface that is parameterized over types. Just like how we define formal parameters used in method declarations, type parameters help you to reuse the same code with different input types. While inputs to methods are values, inputs to type parameters are types. There are three types used by an asynchronous task:. Not all types are used by an asynchronous task; and to mark a type as unused, we use type Void.
Working with AsyncTask is pretty nice until you start doing more complex operations with it. A few instances where AsyncTask would not be useful are highlighted below:. Even though AsyncTask does a good job of performing asynchronous operations, its utility can be limiting due to the reasons mentioned above. Luckily, we have Volley at our disposal, an Android module for making asynchronous network calls.
Volley considerably simplifies networking with its cool set of features. It works in a very simple way:. Start by including Volley in your Android project. Another way to do this is by cloning the Volley repository.
Build Volley with Ant, copy the built volley. You can find the generated volley. You have added Volley to your project without any hassle. To use Volley, you must add the android. The code example below shows you how to make a request on https: We use Volley by creating a RequestQueue and passing it Request objects. The RequestQueue manages the worker threads and makes the network calls in the background.