INTRODUCTION TO RIVERPOD - PowerPoint Presentation

Slide1

INTRODUCTION TO RIVERPOD

Presenter: Sagar

Koju

A state is a piece of information held by a widget when built, and can change when the widget refreshes.Certain data or information stored and passed across or within the widgets in an application is referred to as “the state.”

State management refers to the techniques or methods used to handle the state in an application.

INTRODUCTIONState Management System which fixes some of the limitation of provider that has.Invented by Remi

Rousselet

Compile time Safe, and does not depend on flutter without build context

Support for multiple provider of the same type combining asynchronous provider

Use ProviderScope as a root widget.Comes from Three flavor: 1. riverpod(dart)

2.

flutter_riverpod

(Flutter)

3.

hook_riverpod

(Flutter + hook package)

Comparing Provider and RiverpodRuntime exceptions exist with Provider, but they are handled and corrected with

Riverpod

Provider is not compile-safe while

Riverpod

is

In Provider you can’t declare multiple providers of the same type, while in

Riverpod

, you can do this without overriding the others

In

Riverpod

, the providers are declared globally and can be used anywhere in the app using either

the Consumer Widget or

context.read

Common Provider Used in Riverpod1. Provider<T>: read only value inside the widget

Simple type of Provider mostly used in sharing the data.

final

valueProvider

= Provider<

int

>((ref) { return 36;

});

Does not change the value

2.

StateProvider

<T>: Expose the value to the Outside of Widget.

Similar to the

ChangeNotifierProvider

.

final

counterStateProvider

=

StateProvider

<

int

>((ref) { return 0; });

3. ProviderListener: Used to push the route, show dialog or snackbar when the state change.

equivalent of 

BlocListener

 from the 

flutter_bloc

 package

.

4. State Notifier: State is immutable

Automatically UI refresh.

Not Changeable outside the class.

5. Change Notifier : State is mutable

Manually UI refresh.

Changeable outside the class

Fig: Business logic of State Notifier

watch the model's state and rebuild when it changes.call methods in your model classes (using context.read<Model>

 which in turn can update the state and (optionally) interact with external services.

6. Future Builder and Stream Builder : work with asynchronous code.can rebuild our UI when some asynchronous data changes

.

We get

AsyncValue

<T> when we watch these provider which is a type that comes from the

freezed

package

we can use

the when()

method to map the 

data

, 

loading

, and 

error

 states to different widgets

When to Use Watch and Read Method Watch method is using for combining the multiple provider

Watch method is used

every time we needed to read the value of a provider inside

a build method

read method is used

inside button callbacks or callback handlers.

Fig:

Riverpod

graphical illustration

THE END