Join them, it only takes 30 seconds. Be the first to get informed of the latest Flutter news, insights, and tips and tricks. Weekly summary email on Saturday. You checked out these tutorials the last time you visited. Please upvote the ones you found useful. The developers of Flutter term it as a high-performance and high-fidelity app builder for iOS and Android applications, from a single codebase.
The idea behind Flutter was to help developers create fast applications that feel smooth on distinct platforms. Before you look out for Flutter tutorials, there are a few requisites to learn Flutter.
To begin with, one should invest some time in learning the basics of control structures and the flow of an application. While this should be enough to help you start with Flutter programming, it is also advised to learn the programming language Dart for further proficiency in Flutter. Dart is a general-purpose language created by Google used to build web, server, and mobile applications.
Flutter has gained quite some numbers in recent times due to its ability to help developers focus more on the end product and not the SDK. If you wish to learn Flutter for beginners and gain critical knowledge through comprehensive Flutter tutorials, Hackr. It offers a large number of tutorials which will help both amateur and professional developers focus on learning all about Flutter programming and its features.
All the tutorials available on Hackr. Users can choose Flutter getting started tutorials from a number of options, both free and paid, and decide the mode of the tutorial, which can be either video or book. Follow Flutter on Hackr. Feel free to ask your questions on Flutter forum. Before beginning with learning Houdini, it is advised to look for some basic tutorials about how 3D animation works and its nitty-gritty.
It would also be helpful if you look at some 3D animations done by other developers to get a look and feel of what a complete animation looks like. One can also invest some time in learning a programming language that supports socket communication, such as Python.Performing HTTP requests is all fun and games until there's no internet connection.
Sure, you can display a sad error message or a "Chrome dinosaur" to the user, but wouldn't it be better to take the initiative and automatically retry the request when the user connects to a WiFi network or enables mobile data? This is precisely what we're going to implement in this tutorial. I mean, come on! These will be central to make this auto-retry work. All of the packages and the basic UI is prepared for you in the starter project so that you won't waste time if you want to follow along.
By the end of this tutorial, we'll have created an app with the following behavior:. Interceptors run every time you do some action on a Dio object. You can then perform logic in three callback methods - onRequestonResponse and onError. They are useful for plenty of things such as logging or, in our case, scheduling a request retry when we detect there's no connection.
You are probably familiar with the dreaded SocketException that gets thrown when the device isn't connected to a network.
This means only one thing - we're going to utilize the onError callback. This is the basic outline of our interceptor. We're going to get to the retry logic in just a bit but first, it's important to note that the onError callback will run for all kinds of errors including status codes such as or I think it's a good idea to retry the request only when the error is the aforementioned SocketException. How can we find out which exact type of of an error occurred?
We can use the handy fields of the DioError object! Having the interceptor is only one part of the game. How can we actually schedule the failed requests to be retried as soon as the device is connected to a network? We could just plop this logic right into the RetryOnConnectionChangeInterceptor but I'm a proponent of keeping the code focused on one task. Let's create a DioConnectivityRequestRetrier. We're then going to return the successful Response back to the interceptor which scheduled a request retry.
To retry the request immediately when the network connection changes, the Connectivity class offers a handy Stream called onConnectivityChanged. You may have noticed something fishy going on in the code above. There's no return statement! It's not as simple as returning the result of calling dio. After all, the request happens inside a closure of the listen method and we want to return the Response from the scheduleRequestRetry method.
This is just the right occasion to use a Completer. We can return its Future from the whole scheduleRequestRetrywhich we will then complete from the closure. All we need to do, is to plug the interceptor into it. And just like that, you now know how to retry requests automatically when device connection state changes. It's going to create a much better user experience than just passively saying "no connection, retry by pressing a button".Flutter is known for its extensible built-in navigation.
Even by by using the default Navigatoryou have a couple of options:. You can learn about all of these vanilla navigation methods from this tutorial. Sometimes though, it's good to bring in more structure into navigation. Instead of reinventing the wheel with custom route transitions and logging for debugging purposes, you can let Sailor to do the heavy lifting for you.
We're going to build a very simple app consisting of three pages. One of them is an "initial page" from which we can navigate to the rest. Values which are displayed in the individual pages are passed in from the initial page. The starter project is an already fully working app with navigation. The only issue is that the starter navigation is done by using the default MaterialPageRoute s all over the place.
We will first create a static instance of Sailor and simply call addRoutespassing in our page widgets wrapped in a SailorRoute instance. Apart from the code having a bunch of errors because we're not yet passing any arguments into SecondPage and ThirdPagethere is a more pressing issue to deal with. We have to call createRoutes and also plug Sailor into the navigation flow. Let's first call createRoutes from the main method. This will allow Sailor to resolve route names to their respective widgets.
Sailor gives us two options in how to values into routes. Every builder function of a SailorRoute receives both args and params.
These are represented by a Map which can contain a bunch of values, which is precisely what we need for the SecondPage. Parameters for a route have to be first defined.
Later on, we will implement the buttons inside the InitialPage to pass these parameters in. Once passed in, they will arrive in the builder function where we can extract them and put them into a new instance of SecondPage.
Whenever you can group multiple fields into a class, you should. More so when you're dealing with navigation where it's so easy to get lost. ThirdPage is an example of passing in a class. Sailor handles this with the args parameter of the builder function. Now we can pass ThirdPageArgs in when navigating and use them from within the builder :. Now we're finally going to fit all of the pieces together and switch from the default navigation to Sailor in the onPressed button handlers in the initial page.
Just for comparison, here's the old code which instantiates MaterialPageRoute s directly:. Especially with the approach of passing in an arguments class, we didn't lose out on the type-safety, while we gained a ton with regards to readability and maintainability of the code. In addition to simplifying the flow of data between routes, Sailor also makes defining route transitions hassle free.
It comes with a couple of pre-defined ones which we're going to use now. The process of adding any of these transitions is practically the same. Although I wouldn't necessarily call it a good user experience to have to wait through a two second over-the-top route transition, it shows what's possible in just a few lines of code.
Sailor is the next step when you're fed up with manual handling of navigation through named routes. It supports a nice mechanism of passing data around and in addition, Sailor also simplifies applying route animation transitions.In order to support Flutter Web, v3.
Pagination in Flutter
Welcome to submit Dio's third-party plugins and related libraries here. The Options class describes the http request information and configuration. Each Dio instance has a base config for all requests maked by itself, and we can override the base config with [Options] when make a single request.
The [BaseOptions] declaration as follows:. There is a complete example here. For each dio instance, We can add one or more interceptors, by which we can intercept requests or responses before they are handled by then or catchError.
Flutter HTTP requests with Dio, RxDart and Bloc
In all interceptors, you can interfere with their execution flow. Because of security reasons, we need all the requests to set up a csrfToken in the header, if csrfToken does not exist, we need to request a csrfToken first, and then perform the network request, because the request csrfToken progress is asynchronous, so we need to execute this async request in request interceptor. The code is as follows:. For complete codes click here. You can custom interceptor by extending the Interceptor class.
There is an example that implementing a simple cache policy: custom cache interceptor. Dio has already implemented a DefaultTransformerand as the default Transformer. If you use dio in flutter development, you'd better to decode json in background with [compute] function. There is an example for customizing Transformer. And all we need is providing a HttpClientAdapter. Here is a simple example to custom adapter. There are two ways to verify the https certificate.
Suppose the certificate format is PEM, the code like:. You can cancel a request using a cancel token. One token can be shared with multiple requests.
When a token's cancel method invoked, all requests with this token will be cancelled. Please file feature requests and bugs at the issue tracker. Delete Formdata. The reason is here. The type of Response. Alternatively, your editor might support pub get or flutter pub get. Check the docs for your editor to learn more. We analyzed this package on Apr 15,and provided a score, details, and suggestions below.
Analysis was completed with status completed using:. Readme Changelog Example Installing Versions Get started Add dependency dependencies: dio: 3. Related Projects Welcome to submit Dio's third-party plugins and related libraries here.Our Flutter Tutorial provides basic and advanced concepts of the Flutter framework.
Flutter is a UI toolkit for building fast, beautiful, natively compiled applications for mobile, web, and desktop with one programing language and single codebase. It is free and open-source. Flutter apps use Dart programming language for creating an app. The first version of Flutter was announced in the year at the Dart Developer Summit. It was initially known as codename Sky and can run on the Android OS.
On December 4,the first stable version of the Flutter framework was released, denoting Flutter 1. The current stable release of the framework is Flutter v1. In general, creating a mobile application is a very complex and challenging task. There are many frameworks available, which provide excellent features to develop mobile applications. Thus, we need two different languages and frameworks to develop applications for both OS. Today, to overcome form this complexity, there are several frameworks have introduced that support both OS along with desktop apps.
These types of the framework are known as cross-platform development tools. The cross-platform development framework has the ability to write one code and can deploy on the various platform Android, iOS, and Desktop. It saves a lot of time and development efforts of developers. There are several tools available for cross-platform development, including web-based tools, such as Ionic from Drifty Co.
Flutter is mainly optimized for 2D mobile apps that can run on both Android and iOS platforms. We can also use it to build full-featured apps, including camera, storage, geolocation, network, third-party SDKs, and more.
Flutter is different from other frameworks because it neither uses WebView nor the OEM widgets that shipped with the device. Instead, it uses its own high-performance rendering engine to draw widgets. It also implements most of its systems such as animation, gesture, and widgets in Dart programing language that allows developers to read, change, replace, or remove things easily.
It gives excellent control to the developers over the system. Flutter gives easy and simple methods to start building beautiful mobile and desktop apps with a rich set of material design and widgets. Here, we are going to discuss its main features for developing the mobile framework.
Open-Source: Flutter is a free and open-source framework for developing mobile applications. Cross-platform: This feature allows Flutter to write the code once, maintain, and can run on different platforms.You are tweaking an app which is already in production. You are implementing code that allows a user to delete his data.
All of a sudden, you realize that you made a huge mistake! By providing a wrong ID, you accidentally deleted data of an actual user! Horror stories like this one can truly become a reality if you don't have separate production and development environments.
To keep this tutorial in a reasonable time-span, we won't deal with Firebase but we will instead create environments for a counter app! Well, now you'll see what you missed! There are 2 ways in which to configure multiple environments - either by providing a config file this is the case with Firebase or by passing around an Environment enum or a constant String this is usually used with dependency injection. We're going to tackle both of these approaches. Also, how can we use the proper environment when we build the app?
Additionally, config files can contain sensitive information which we don't want to check into source control How can we handle that? The answer is Codemagic and multiple branches in a git repo. However, before we can set up that kind of stuff, we have to first create a Flutter project. As you already know, we will build yet another variant of the counter app. The UI code will remain fairly unchanged.
Changes to the default counter app are highlighted.
Pretty standard stuff, if you ask me. The difference from the default counter app lies in getting the increment value and also a "secret key" from a config JSON file using a ConfigReader. The primary theme color is gotten using Provider - changing the color is accomplished using environment const String. Files present in the project are perfect for providing non-dynamic configuration. This can range from an increment amount for a counter app to various secret keys or even a Firebase config.
The problem is that we don't want to check secret keys into source control. After all, all kinds of people can have access to the repository even when it's private contractors, etc. That's why it's good to add the config file into the project only at build time with Codemagic.
Still, we want to be able to develop the app locally so we have to keep a copy of at least the development environment config on our machine. To prevent this file from being committed to git, we'll utilize. Now that we know the structure of the config file and also that it's available as an asset, we can implement the ConfigReader class.
Note that the initialize method has to be called from main. We'll do that later. Having a config file is only one way to differentiate between environments. The other way is having multiple entry points a. Let's first create the constant strings which will be passed around the app.
It's also possible to create an enum instead. We want to have two environments - dev and prod. Now onto the entry points! If you're not aware of it, the flutter run and flutter build commands take in an option called --target or -t for short.
These usually don't contain much code in themselves. Instead, they delegate all of the work to a common main method.Flutter is an open source framework to create high quality, high performance mobile applications across mobile operating systems - Android and iOS.
This tutorial walks through the basics of Flutter framework, installation of Flutter SDK, setting up Android Studio to develop Flutter based application, architecture of Flutter framework and developing all type of mobile applications using Flutter framework.
This tutorial is prepared for professionals who are aspiring to make a career in the field of mobile applications. This tutorial is intended to make you comfortable in getting started with Flutter framework and its various functionalities. This tutorial is written assuming that the readers are already aware about what a Framework is and that the readers have a sound knowledge on Object Oriented Programming and basic knowledge on Android framework and Dart programming.
If you are a beginner to any of these concepts, we suggest you to go through tutorials related to these first, before you start with Flutter. Previous Page Print Page. Next Page.