get_it (Package of the Week)

Learn more about get_it → goo.gle/3HZugEA
If you've ever had to organize non-widget resources like data repositories or network connections, you know how much of a challenge it can be. Have no fear - `get_it` is here!
This video is also subtitled in Chinese, Indonesian, Italian, Japanese, Korean, Portuguese, and Spanish.
Talk from the get_it author → goo.gle/3f39w2c
Follow Thomas on Twitter → goo.gle/3HEpM60
Learn everything about Flutter at → goo.gle/2WAhEN1
Get more tips → goo.gle/Flutte...
Subscribe to Flutter! → goo.gle/FlutterYT
#PackageoftheWeek #Widgets #Flutter

[@deeplight1417]

For those who wonder what's the purpose of this library, the main usage is for dependency injection (like in Spring for example). It has most of the functionnalities required to do that.

[@paucolome4298]

For angular devs this is a blessing

[@CryptoWulf_app]

@@paucolome4298 The example shows how to get a bloc. You could just use repository provider for your services and blocprovider for your bloc and dont need an extra dependency/get_it.

[@allphredo]

I don't get it :(

[@dkdanish8143]

I recommend first understand about dependency injection and service locator which are popular patterns used in software development.

[@thesunstep]

@@dkdanish8143 Breuh I think u missed the joke

[@rajveersingh2056]

Get_it explanation is incomplete without a pun and saying "get it?" at the end

[@maxc9432]

we need a remake hahaha

[@ByHassanBasri]

well this is the first time , i didn't understood anything by watching your video (otherwise I have learned something from every package video ,) like what is the benefit and why to use it? other videos are very helpful may be the narrator and producer has changed ?

[@michasengotta2295]

You know how Providers reach dependencies down the widget tree and whenever you need something, you can use a Consumer to retrieve that thing from the BuildContext? Sometimes you don't have a context at hand (for example inside a service method) and some things don't even care about their location in the tree. So why would you reach them down the widget tree? Simply put: You don't have to. That's where get_it is super helpful! You can just get the thing anywhere, because it's a singleton (which means there is just one of it's type). What they call dependency injection (DI) is just a fancy word for not having to reach concrete stuff around, but instead automatically getting the things you need at runtime, so you can mock them easily for testing.

[@mlazebny]

@@michasengotta2295 That's where get_it is not helpful. Why don't you just use global variables instead? You need to use Constructor Injection in your services, logic layers, etc.

[@allenrichardyeager8449]

same here

[@ivanyoed]

People, people. Guys. Remember that global variables can be altered by any part of the code, making it difficult to remember or reason about every possible use. ... Using global variables causes very tight coupling of code. Using global variables causes namespace pollution. The problem with global variables is that since every function has access to these, it becomes increasingly hard to figure out which functions actually read and write these variables. Just had to google a little to find so many reasons to prefer other ways to manage data in your app.

[@michasengotta2295]

@@mlazebny Global variables are an anti-pattern for the reasons Iván provided. But even global constants are a mediocre option, because you don't want all of your code to depend on the place where you keep the variables. Inversion of dependency is the way to go here. You don't fetch the variable, but it gets delivered to you :) You bet the Google team knows this, which is why this is their package of the week!

[@ivanyoed]

Sweet. Please keep doing such amazing videos about packages which help us to code while following appropriate patterns.

[@amirgamil]

Nice!!! More like this please! Understanding Flutter best practice in this way is great and I've always wanted to know what Flutter's DI options were 👍 Would love to hear more about this and other topics in this vein.

[@강수경-j1b]

Thank you for korean subtitle :D

[@mrCetus]

I really didn’t understand the use of this one, since I’m using contractors for what object I need and static variables for the app need to use during the session, so does this one provide a way that I can get the objects or what construct I have for later use in the app, like static variables!?

[@JenuelDevTutors]

is their a video about best way to structure folders in a project? like creating service folders, jobs, etc. ?

[@WahyuHidayat-my1ky]

better watch clean architecture course by reso coder

[@Lensbreak]

Just use Riverpod?

[@Raimkhodzhanov]

I love Flutter!

[@AJFlutterTutorials]

awesome)

[@tech4nobs205]

Awesome 😎

[@israelhudson]

If it's possible not to use context safely then is package "get" also recommended?

[@codeage1]

What ist the difference to the Singleton Pattern?

[@alexanderphatom5410]

nothing

[@ulbsualbrykya7141]

Using get_it as dependency injector/service locator makes life much easier to create "fake" instances and mock testing

[@saqqara6361]

Singleton Pattern is not dependency injection, which is done by get_it.

[@michasengotta2295]

The things you provide to get_it are actually singletons. It's just the fact that you 1. have a unified way of accessing all your singletons and 2.: you can change them out at runtime, which you couldn't if you depended on concrete classes. You can however write something similar to this with little code, so it's up to you.

[@ShawnBlais]

Think of them as testable singletons.

[@scottcollins4456]

Are there any packages for flutter that provide constructor injection? I have always tried to stay away from service locators as much as possible, so this package isn't exactly what I was looking for in a DI framework.

[@ShawnBlais]

Not that I know of. All options in Flutter are service locators of one type or another. Provider, riverpod, inherited widget, etc

[@mrverdant13]

what about riverpod

[@pradeepg4498]

Getx

[@trapeye3464]

what different from provider?

this video deserves a better version hehe

[@krtirtho]

I don't get_it What's it's purpose?

[@md.safiqulislam2944]

Every widget video talk description. We want that describe give comment section.

[@TheGamingAlong]

I don't get_it .

[@DaewonTech]

nice one

[@melianiabdelghani371]

Can i ask about the difference between this and the other methods of state management ?

[@mmazurovsky_r]

It is about dependency injection, not state management

[@RamVerm]

get_it is not a state management system or solution. It is used for dependency Injection. Dependency injection is used for storing, locating instances of classes and injecting it directly into widgets or methods which results in a much more cleaner and readable code rather than passing down the instance in a widget tree. It is especially useful in a complex app but normally you won't need it.

[@jimmorrison2657]

@@RamVerm What is the difference with this, and holding all instances in a singleton, and getting them from there?

[@danijeltolj7052]

@@jimmorrison2657 Using get_it in combination with abstract classes makes the code much cleaner and decoupled. Holding all instances in a singleton makes it so much harder to test and dangerously expensive in terms of memory management. Lastly, it makes testing the app a breeze, because everything is decoupled.

[@jimmorrison2657]

@@danijeltolj7052 The decoupling could also be done with a singleton. The singleton would only return interfaces, and you wouldn't need to know which concrete implementation you are getting. For testing, you could pass test implementations into the singleton on app start-up, then these would be returned by the getters. About memory management, I think you are wrong about this. I don't see any reason why a singleton would require more memory.

[@Brayanpr27]

Saludos desde Colombia fluttermens

[@j.almadhaji]

we need a full example of it I am using it with provider, but I wonder if I am using it the right way

[@mmazurovsky_r]

Get it is great!

[@NahomyUchija]

When HiveDB ?

[@alexanderphatom5410]

After that there will be no point in watching this channel at all

[@mr_ks_gaming]

@@alexanderphatom5410 why tho ?

[@SunFoxx_]

Clearly many people in the comments did not get_it *badum tss*

[@michelfeinstein]

Unfortunately service locators can't be statically verified, so you will get runtime erros if you fail to define a dependency. This is a frequent source of bugs. I wish dart/flutter had a good DI injection mechanism, like other technologies have.

[@levilesches7783]

Personally, I define a static field on my service called "instance" with the singleton object. It's safe, since if you don't define it you can't reference it, cleaner by making DI redundant, and aligns closer to more prominent SDKs, like Firebase

[@michelfeinstein]

@@levilesches7783 not all dependencies are singletons, so we still need mechanisms to create instances on the fly.

[@neociber24]

Others technologies use reflection and I think Flutter doesn't allow it.

[@michelfeinstein]

@@neociber24 The same can be done with code generation, that what's Dagger does on Android.

[@ShawnBlais]

@@levilesches7783 Yes, singletons are more robust, but they are harder to test/mock (well impossible really). GetIt adds a little sugar on top, to solve this limitation. imo the RTE's are not really a problem with singletons in practice, they don't typically just disappear, and you shouldn't have tons of them anyways. Singletons should be major actors in your app. The error issue is when using service locators for general instance injection, where you might insert non-singleton like objects all over your app. Then all of a sudden you can get into a case of lots of runtime errors "Cant find thing X". I stay away from that practice personally, as it seems like an obvious anti-pattern. My Flutter projects generate far too many widgets, to be injecting state at different levels of the tree and then trying to find it later.

I didn't get_it 😅

[@DL-gg3sb]

Pk. Google map can not setstate pin on web. need fix

[@ahmedtiger3809]

i don't get it this one :)

[@kamil_supabase_enjoyer]

Just use Riverpod instead

[@mlazebny]

Nah. Get it, really? I see that the next video will be about GetX, yep?

[@michaelkadziela7460]

Those two packages aren't related

[@ivanyoed]

@@michaelkadziela7460 yeah, not at all.

[@nested9301]

Gooobrr

[@danielsanchezsa6428]

So... its like Provider?

[@ShawnBlais]

When combined with `GetItMixin` it acts almost identical to provider, except you don't ever need to use `context` to look things up :)

[@Lensbreak]

@@ShawnBlais Riverpod does that too?

[@ShawnBlais]

@@Lensbreak Yes, but substitutes a `ref` object instead, which must be similarly passed around.

[@livingstongraphics]

cool

[@serkankaya9907]

Yeah :)

[@321Tdog]

Siick

[@أبوتميم-ح6ط]

Thank you flutter from my heart, but if you translate the clips into Arabic, thank you again 💐

[@TrongTran-zv6ci]

Wow, now I get_it :)

[@joranmulderij]

I get it.

[@virgiliustancu9293]

After "null safety" Flutter became very confusing.

[@gilangs8484]

For me, null safety is very helpful

[@BrazilMentionedHueHue]

hmmmm I get it

[@AJHopeTV]

5th)

[@ROWROLLIN]

7번째

[@dskygn]

Not clean, does not understand anything. State management packages sucks in flutter, very disappointed.

[@ankitmahadik4081]

Second ;)

[@ShanXiTV]

if you are accessing repo or db from UI, u r doing it wrong. Move that logic to bloc.

[@BenMcNelly]

Third?

[@ahsan_khan44]

4th :p

[@baxiry.]

6th

[@srujanmhase2832]

First ;)

[@vanhelsing4454]

I thought its a video about GetX

[@mazudhafiz1778]

Different :D

[@ElVerdaderoAbejorro]

It's a shame that in 2023 people use the terms "Service locator" and "Dependency Injection" as if they mean the same thing. Service Locator is an anti-pattern. Read "Dependency Injection: Principles, Patterns and Practice" if you don't know the difference. Shame on this video for pushing towards a SL library instead of true DI.

[@csibesz07]

service locators = DI frameworks - explicit dependency declarations

[@nimrsawafta1682]

I really didn’t understand the use of this one, since I’m using contractors for what object I need and static variables for the app need to use during the session, so does this one provide a way that I can get the objects or what construct I have for later use in the app, like static variables!?

[@ShawnBlais]

It's essentially a singleton manager, globally accessible objects, accessed by type from anywhere in the app, easily mocked/replaced.

[@javieroviedo4844]

Static variables that hold states are an antipattern because they difficult unit testing and a couple of other reasons. This is suppose to be a service locator that easily lets you control the lifetime of the service and decouple its dependencies, it appears to be heavely inspired by the dependency injection of the .net ecosystem, is convenient because it facilitates mocking that dependency too.

[@xylineone]

This is something like spring for dependency injection

[@j.almadhaji]

define it out side the class or any function, then assign to it what you want later before the RunApp(), you will be able to access it from any where. final getIt = GetIt.instance;

[@ahmedhesham3916]

I didn't get_it 😅

[@alexcom_]

I don't get_it.