Dart is essential for those wanting to build a cross-platform app using the Flutter framework. It enables you to build sleek user interfaces that have a truly native feel. However, it takes practice to be able to leverage all the benefits of the language and framework. Therefore, if you’re planning on building an app with Flutter, it’s worth knowing some tips and tricks that can improve your coding style and help you to create an incredible solution.
What is Dart?
Dart is a client-optimised programming language for building mobile, desktop and server apps. The language was developed by Google specifically for use with its cross-platform Flutter framework. Some of the most notable features of Dart are that it is:
- Object-oriented – the programming style is characterised by the identification of classes of objects that are closely linked with the functions with which they are associated.
- Class-based – the object-oriented programming style enables inheritance by defining classes of objects instead of through the objects alone, as is the case for prototype-based programming.
- Garbage-collected – Dart includes a memory recovery feature that automatically frees up memory space that has been allocated to objects no longer required by the program.
- C-style syntax – Dart uses the C programming language to create programs that are extremely terse, have a close relationship with the object code and, at the same time, deliver a high level of data abstraction.
Top Tips for Better Dart Code
1. Use Anonymous Functions as Arguments
In the Dart programming language, there are anonymous functions that don’t need a name and can be directly passed as arguments to other functions. This is a great trick when it comes to things like functional operators, as the anonymous function has the same signature, and avoids having to expand the code further.
2. Implement a ‘Call’ Method in Dart Classes
With Dart, you can use the call method to make classes callable like functions. This is done by creating a callable class that allows that class instance to be called as a function. As the method is called a call, you can declare a class instance and use it as if it were a method. It’s worth noting, however, that Dart doesn’t support multiple callable functions.
3. Iterate Through a Map by Using ‘.entries’
To iterate through a map in a null-safe manner, Dart enables you to use .entries. The code is improved and made more null-safe using a loop. You iterate with the entries variable and can then access your key-value pairs in a null-safe way. Using entries in this way is more consistent and less error-prone than the alternatives.
4. Use Getters and Setters to Improve the Design of Classes
Getters and setters are special methods that offer read and write access for an object’s properties, enabling you to define computed variables. They are called in a similar way to instance variables, with a dot operator followed by the function name, get or set. Getters are functions that retrieve the values of an object’s property, whereas setters are used to write the values of an object’s properties.
5. Use a Set for Collections of Unique Items
While a list is the most common collection type in Dart, it can hold duplicate items. If you want to create a collection of purely unique values, it is a good idea to use a Set instead. In a Set, no two elements can be the same and the code offers a warning if it doesn’t compile. What’s more, by working with sets, you have access to useful APIs, including union, difference and intersection.
6. Try Out the Inspect Widget
Most developers will use the Inspect element to find all the properties applied to an HTML tag. However, in Dart, you can use a similar feature called the Inspect Widget, which can improve app development with Flutter. The Inspect widget can be used to locate any widget on the screen and view its properties and can also help to visualise widget trees to understand layouts.
7. Utilise Sync and Async Generators
There are two generator functions in Dart that make it possible to produce a sequence of values. The synchronous generator returns an iterable object, a collection of values that can be accessed sequentially, whereas an asynchronous generator returns a stream object, a sequence of events.
8. Make the Most of Collection-if and Spreads
You can use collection-if and spreads with lists, sets and maps. Most developers know that they are really useful when writing your UI as code but they are also incredibly useful with maps as well.
9. Learn Common Future Constructors
The Dart Future class has some extremely useful factory constructors including Future.delayed, Future.value and Future.error. Future.delayed can be used to create a Future that waits for a certain delay, Future.value creates a Future that completes immediately and Future.error can be used to complete a Future with an error. The three constructors can be used to simulate the response from Future-based APIs and are really useful for writing mock classes in test code.
Developing Better Applications with Flutter
Flutter and Dart are a powerful combination of tools in a developer’s toolkit that help build beautiful, native-looking apps. By knowing these tips and tricks, Flutter developers can make the most of Dart and the features it offers and drastically improve their code.