Injectable - Flutter & Dart Equivalent to Dagger & Angular Dependency Injection

[@matiasosuna6812]

Reso! Could you update this tutorial? Like this for him to see it

[@andres-rodriguez]

15:07, thank you it made sense. But I tried removing line 15 and 16, and everything still ran. Those two lines are redundant in my opinion. But I made sure to include CounterChangeNotifier dependency right below. I am so happy you share your knowledge and I learn a lot from you!

[@psybitcoin]

Love it! WOuld also love to see you working with Firebase in Flutter

[@aytunch]

Hi Matej, can you briefly explain at exactly which scenarios we usually need the use of a Singleton/D.Injection/ServiceLocators that you show in this tutorial? I guess database provider is one of them. Other than that, if we are using Bloc or provider, why do we need to use these strategies? You stated for not having spaghetti code. Is that the only advantage? For a production quality app, what parts/modules need to take advantage of these strategies? Thanks. I hope you can make a tutorial for this very question: explaining when to use these solutions. Thanks man

[@deoneloff]

Very nice! This makes a huge difference to me. Thanks a lot, once again, for a most valuable Flutter training session!!

[@reprevise]

Can you make a video on the difference between factory, singleton, and lazy singletons and when to use them?

[@bogdanb904]

First, let me tell you what a singleton is. A singleton class ( whether you call it a service, repo, etc. ) is a class that gets instanced only ONCE for the whole application's lifetime. It usually has a private constructor, so you cannot create an instance of that class by yourself. A singleton gets gets instanced when the application is started. A lazy singleton is instanced only when it is first demanded. Now, factories can also be called 'instance-per-request'. Whenever you need that class, it gets instanced. As far as example goes, think of a service that holds the current theme of your application ( e.g dark / light ). You would want that to be a Singleton, since you want to have the same theme state in any of your screens.

[@codersplayground4391]

The abstract class annotation must always be equal to the annotation of the implementation class ?

[@sinazp8422]

are u magician ? this was great content , thank you

[@focaapp516]

Man I really admire your work, I wish to help people learning flutter like you do, but time is a really valuable resources that I will I had more. Even then you save me a lot of money finding this awesome libs.

[@khanaa13]

This package and tutorial is absolutely mindblowing! 🔥 How would you register sharedPreferences with this seeing as how you normally do final sharedPreferences = await SharedPreferences.getInstance(); getIt.registerLazySingleton(() => sharedPreferences); Injectable does not allow you to specify third party classes as being injectable Right now I'm resorting to creating a separate file for ones that have custom ways of setting up their instances, mimicking the style of the generated file but doing the injection manually and then calling this custom function in main.dart too

[@ThalesFrigo]

Good question

[@ResoCoder]

Exactly what I found. This is the very first release of injectable so it has some loose ends, unfortunately.

[@BrysonThill]

One alternative is to write a wrapper class around SharedPreferences and make that @injectable.

[@khanaa13]

@@BrysonThill Yes that's what I said

[@BrysonThill]

@@khanaa13 I think we're talking about different things. You said you manually did the GetIt configuration for these third party classes and called another function from main. The alternative I proposed is to create a new class like InjectableSharedPreferences that wraps SharedPreferences, which you can annotate using @injectable and not use two separate code paths for your configuration.

[@jimaustin3608]

Both ‘follow-along’ code and master show build_runner fail; looks like a null-safety problem caused by the newer null-safety relaeases. Failed to precompile build_runner:build_runner: /c:/flutter/.pub-cache/hosted/pub.dartlang.org/build_runner-1.7.3/bin/build_runner.dart:87:9: Warning: Operand of null-aware operation '?.' has type 'StreamSubscription' which excludes null.

[@evandrobarbosadosreis]

That's exactly what I was looking for. Greeting from Brazil.

[@codersplayground4391]

What’s that shortcut you used to correct dev to prod on both the variable and value ?

[@nicholasmiller5731]

Do you know if Injectable offers dependency inversion also? I was took aback when I saw you add the @bind annotation on ICounterRepository, rather than on the Dev/Prod implementations.

[@Abion47]

The link for the written tutorial seems to be broken.

[@ResoCoder]

Thanks!!! Damned Wordpress 😒

[@BrysonThill]

All your dev and test implementations will get bundled into your prod builds when using this strategy, right?

[@ObiWanKenobi_IceNation]

Watching this a year later, and was thinking about the very same thing. The answer is yes, and I don't like it at all..

[@CarlosHernandez-dv1ib]

man i had to watch like ten times this video, now i understood, thanks so much!!

[@vaibhavdangayachvd]

How can we seperately test our development and production environment?

[@verryondrums]

You are using an "I" in front of the abstract classes/interfaces. So it's "CounterRepository" for the actual implementation and "ICounterRepository" for the abstract class. Is this a convention? Couldnt find something on the "dart convention guide". Before you used this kind of naming you used "CounterRepository" for the abstract class and "CounterRepositoryImpl" for the implementation.

[@scottatkinson6339]

Coming from a .Net background it's widely used by many developers to utilize the "I" when implementing an interface then dropping the "I" when implementing the class that will implement the interface. IUserServce

[@stevenstone307]

It seems to me that you should be passing ICounterRespository into the ChangeNotificationProvider. If you're explicitly passing the service class, doesn't that defeat the purpose of dependency injection?

[@silverqui.9698]

Hi Im dealing with something and maybe you can help me, how do you inject SharedPreferences ? I tryed the example given by injectable documentation @registerModule abstract class RegisterModule { @preResolve Future get prefs => SharedPreferences.getInstance(); } but is not working, have you tryed something with SharedPreferences?

[@karlon908]

Would like to see if we can connect the environment configuration to CI/CD configuration like in codemagic that would be nice, automated build and can change environment automatically.

[@ResoCoder]

You can and I will create a tutorial on that soon.

[@karlon908]

Looking forward to it! Thanks!

[@marialijideveloper2006]

Hi, 'Sensei' Reso Coder, thank you for wonderful job!!, I have this issue : [ICounterRepository] is abstract and can not be registered directly! cause this at the moment to run appears this error : 'Receiver was call on null'

[@bogdanb904]

Which would you advice to use? Provider or this? I'd like to start my first project but I can't make my mind. I'm coming from an Angular / .NET background so Dependency Injection looks appealing to me but I don't know how well it would scale in flutter.

[@777phoenix2]

Provider and get_it is easy

[@bogdanb904]

@@777phoenix2 What would the advantages be? Besides the boilerplate code needed for Dependency Injection.

[@777phoenix2]

@@bogdanb904 I think this injectable is ugly I saw this video in the half and closed the browser because do not like it. Provider and locator pattern is easy and I think that is no boilerplate. But this is uglier than that...

[@bogdanb904]

@@777phoenix2 It's not about easy / boilerplate. It's about scalability of the app. I' m talking about huge apps, not some weather app or TO-DOs app etc.

[@ResoCoder]

I have found that this injectable package has some unfinished parts, which is kind of expected from such a new package. As of now, you cannot register 3rd party classes easily. I wouldn't use it in big projects RIGHT NOW, but in the future? Yes!

[@programan6391]

What's your strategy to move code between dev and prod?

[@scottatkinson6339]

Great video, how do you handle multiple providers though whilst using injectable? as you only use one in this video. Can anyone help?

[@easazade]

how do we pass parameters to factories?

[@IngPedroAraujo]

Great tutoril, thanks for it. Is it possible to implement this using Riverpod?

[@rarescruceat]

Great tutorial! Good job!

[@g-tensolution8527]

What about ready Signal ?

[@joeng7424]

I don't know why we have to complicate things with these DI packages when we already have Provider & ProxyProvider in case of using Provider. And I never like code generation cause it makes me feel like I'm not in full control of my code in which I'm writing.

[@ResoCoder]

ProxyProvider is a complication from my point of view.

[@bogdanb904]

The Inversion of Control and Dependency Injection patterns are widely used in many frameworks and programming languages. E.g. Angular, .NET (C#)

[@777phoenix2]

@@bogdanb904 but you can create apps without them. It is not too hard.. I think this injectable is too ugly, I prefer only get_it and provider...

[@arifikhsanudin9724]

How about end to end testing, sir?

[@SEOTADEO]

Very nice video, thanks a lot!

[@kh_ysf]

please What's the deference be between factory and singleton and lazy Singleton!

[@ResoCoder]

Factory creates new objects every time it's called. Singleton reuses the same object. Lazy singleton's instance is created only upon first request, whereas regular non-lazy singleton instance is created as soon as the app is launched in the main() method.

[@kh_ysf]

@@ResoCoder many thanks 🤗🤗🤗😘 but can u make video to explain it in example? when we need to use singleton not lazy singleton for example and thanks u again 😘

[@thomasmabika7291]

Map, how can I use the build in 'convert' package to turn that to json?

[@Abion47]

Is there a particular reason you have for using a `Map` as a key for another `Map`? That seems like a recipe for a bad time.

[@thomasmabika7291]

@@Abion47 yeah, I kind of figured, ended up using an int instead.

[@alexandervasilenko7773]

Awesome video! Waiting for the next ones... Thanx a lot for your effort!

[@ResoCoder]

Thank you!

[@hollaraywaju1]

I really love this. Thanks so much

[@BonBaisers]

You should use @RegisterAs on implementation class instead of Bind.toType on the contract class as it introduces an "ugly" cycling dependency. Your domain must stay out from implementations.

[@alekseituichiev9300]

This is an important note. 👏

[@anaselmansory6192]

Color and icon extensions?😁

[@francescofreddi4374]

i dont know why injection.dart product this: void $initGetIt(GetIt g, {String environment}) {} have GetIt g more and injection.dart go in error!

[@marialijideveloper2006]

I had the same error than you, so I did this little change : final getIt = GetIt.instance; @injectableInit void configureInjection(String enviroment) => $initGetIt(getIt); and now it works !!

[@faisalmushtaq2287]

Can you make an App series like you made Weather Forecast app with Android but this time with Flutter.

[@afifnadaf9321]

Amazing.. very informative.

[@programan6391]

Best Flutter content

[@PayamA]

Amazing. If you make a video about using injection and bloc that would be awesome

[@khanaa13]

What is special for the case you have Bloc? The process should be the exact same as in the video

[@PayamA]

@@khanaa13 I'm using BlocProvider in a stateless widget and then a statefull widget as its child. this is where i get confused.

[@harshjoshi1067]

Nice one sir

[@MrARBN]

Hey again. And thanks sharing this experience. Im an android fan so i really like native programming, but in few weeks ago im going to instrest to flutter. Im your huge fan, believe me. Your kotlin toturials really helping me out there, now i want to start your flutter toturials. So i hope you tell me a time line to watch theme. Which one is for beginners like me and show me the steps to learn it. By the way. I steel hope you get back to kotlin 😊😊😊. Thank you and see you around.

[@tintin537]

Thank you 🙏 keep up the good work and best wishes for you

[@tintin537]

I just came by to tell you that I am working on a project. which this helped me a lot and saved me a ton of time.

Record a video about flutter_modular.

[@_dinesh]

Is this out an dated tutorial? @Bind is longer exist? 🙄🙄🙄

[@peetcoetzee]

Congrats. Welcome to Bitcoin SV !

[@manishgautam2424]

Please code According to new Packages

[@manishgautam2424]

@module abstract class DiModule { @dev @injectable ICounterRepository devCounterRepository() => DevCounterRepository(); @prod @injectable ICounterRepository prodCounterRepository() => CounterRepository(); @test @injectable ICounterRepository testCounterRepository() => MockCounterRepository(); }

[@PH923]

Thx for the video. Too much configuration imo. I love the idea of Flutter as a technology but It is still immature. This needs a CLI to automate all the config staff. We will see if Flutter gets there.

[@RIAJULISLAMI]

What do you think about Koin: pub.dev/packages/koin

[@kretynek1]

What is the point in declaring implementation upon abstraction...? You know that in most languages you would receive cycle, and even would not compile? Man, you are showing people how to code and make such things.... :|