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Come back.

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So in this video and maybe also in the second one and the third one, so in the next couple of videos,

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we are going to refactor our application.

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So we really need to make a couple of changes, as you have seen in the presentation.

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So we're going to use call routines, for example, instead of calling retrofit directing.

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So let's just get started and rebuild our application step by step.

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This will be quite tricky.

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And um.

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Well, the idea behind it is that you on one hand, will learn movement.

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On the other hand, you will learn how to refactor your own application.

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So if you will have built something already and now you want to refactor it so that it will use a certain

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architecture in this case and VM, then it will be really helpful to do as you will see.

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So here's the difference.

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If we want to use a suspend function, a call routine here instead of retrofit, what we need to do

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is we need to add the suspend keyword.

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Now this function will be a call routine function, which is a function that can run in the background.

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But then what we need to return is not going to be a call, but just the top response itself.

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So here we don't need to return to call.

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And the same thing goes for dysfunction here, so get articles by category.

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Let's make that a suspend function as well.

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We're going to look at the others later on, but for now, let's just add those two.

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Then.

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Let's jump over to our news manager and in our news manager, we need to create news while a service

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as a parameter to the news manager.

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So here private vol service, which will be the news service.

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So now we're passing the news service to our news manager as a service and then the function that we

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had there.

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Get articles.

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This one?

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You see, now doesn't work as we had it before.

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So instead of running all of this stuff that we had in the past, we're going to really simplify this.

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And we're going to use an AOL dispatcher now, so let me get rid of this entire part.

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So we get a service now, so we don't need to use the retrofit service anymore as we did, and we get

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rid of this as well.

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So the articles function will now need to get the country, which will be of type string, and it will

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only return a top news response where we are going to build that with context.

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So here with context.

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Like soul and we this pass a dispatcher, so an old dispatcher, i o standing for input output.

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So dispatchers start i o and then inside of it, we are going to then.

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Use our service, so service that get top articles, and here we needed to pass in the country, which

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will be this country here.

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In order for this to work, we need to make this a suspend function also, only then can we use with

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context.

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And you see, we cannot use get articles like we did in the in it any more.

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We don't need to do that anymore, so we can get rid of that as well.

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Now, as I said in the presentation, we will need to create a repository where we can then pass our

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manager, slash our news manager.

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Which I'm going to put into a new folder slash directory or package, which I'm going to call data.

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And into data, I should actually put our models as well, because if you look at it, that's where

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it would fit.

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So we could refactor it and put it in there.

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But for now, I'm just going to create my repository in here, which will be a Scotland file class,

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a class to be more precise, and I'm going to call this one repository.

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Like so so this repository will need a manager, which will be our newsman that year.

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OK, so I will be required and use manager.

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We need to import news manager for this to work.

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And then inside of this repository, we can now get the articles so we can just go ahead and get articles,

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for example.

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And in order to get the articles, we're just going to what we're going to assign the manager to get

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articles methods directly in here for the US articles.

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OK.

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Like so.

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And then accordingly, we will also have a suspend function for to get articles by category.

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All right, so here.

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Well, if we want to get it by category, we need to pass in the category, which will be of type string.

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And this will be why we're going to assign manager dogs, get articles by category with the category

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and here like this with the category?

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Let me see where we get that from.

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I did write it incorrectly here.

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I call it category.

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OK, so with the category that we get here, we're going to assign it to our articles, my by category.

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So what we have here is a single expression function, and what it does is it just returns what's to

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the right of the equal sign.

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So it's just going to return, whatever, to get articles method is going to do and it returns a top

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news response.

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All right now, we are going to require a new.

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Class as well here.

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And I'm going to put that in here.

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New class and this one will be called main app.

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All right.

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And this class will return an application.

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So this will be our actual application class main app.

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And here we need to have the brackets as well as import application.

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So what should happen in this main application?

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Well, the main application is going to handle stuff.

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So in this application class, we're going to initialize the newsman that your first as the first well

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as the repository needs it when we initialize the repository, providing the manager as an argument

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would use by lazy to ensure they are only initialized at the point of use and not directly when the

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main app is created.

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So private vault manager by lazy, which will then create a news manager where we are passing the API

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DOD retrofit service.

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So let's import news manager here for us to be able to use it.

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And then we need to have the repository as well.

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So repository, which will be created by lazy as well here.

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So only once it is required, so repository, which is the class that we created earlier and we're going

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to pass our manager as the manager.

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So let's import repository.

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So it's this one, right?

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Where do you recall that we needed to assign or pass a manager to our repositories so that we can then

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use it in order to call the Get Articles method, as well as the Get article by category method?

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And then we can make suspend functions from them so that they will be run in the background using call

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routines, because suspend is the key word that we're assigning to a function to make it a call routine

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function.

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So a function that will not run on the main Fred, but will run in the background and will notify us

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once it's done executing whatever it needs to execute.

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Now that we have our main app, we need to assign our main app as the app in our Android Manifest because,

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well, in here currently.

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Check.

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We don't have an app while we have the application here at the top and the app name is not defined,

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so here it's just name.

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And you were just going to use our domain app.

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So how you do it is used as Android name property and you assigned domain app to it.

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OK, which is our main app.

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So this will be the application that will take care of all the entire episodes because will be our app.

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All right.

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And now we can actually create our VM, which means our view model.

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Well, I'm going to put into my U.I folder, so here.

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And you I am going to create a new class, which I'm going to call main view model.

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All right.

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And this class main view model needs to have an application.

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So we need to pass our application to it and it will return Android View model.

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And this one needs to have the application that we are getting earlier or that we're passing as well.

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So now we need to get the repository from the main app in here.

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So let's get that by creating a new variable where we're going to pass or store it repos the toll free,

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which we are going to get from our application main app.

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So here, main app.

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And there it was our repository.

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And let's import May repository for rape like this.

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So this allows us to get our repository on our main map or men app here.

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And then we need to create a smarter and better for our news response, which is a mutable state flow.

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So here private vol news response, which will be immutable.

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State flow with a top news response.

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All right, so let's import a mutable state flow here.

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This class.

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Like that?

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And now we can create the news of response.

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Which will.

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The F-Type's state flow with the top news response.

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And let's import state flow as well.

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And then finally, get or have the getter, which will give us the news response.

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So for this view model class, we will focus on the top news first.

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We will use to Android View model instead of the view model.

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This is because we need access to the application class, which comes with the Android View model will

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get the repository from the main app using the application context, which is this get application here

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and create a certain and getter for the type mutable state flow and state flow as a holder for the articles

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response.

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So it holds our top news response.

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So here, private Vul on underscore score is loading will be immutable.

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State law.

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Well, I'm going to pass through to it.

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So is loading is going to be through and then let's create the.

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Public state flow here to one that we can access state flow Boolean, which will.

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Just be our is loading.

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And here is loading like this.

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So let me check, is bullion equals just loading.

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Okay, there needs to be an empty space in between.

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So this will be the variable that checks the loading states and then we create a method to launch to

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get articles.

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Method so fun gets top articles.

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Which is checking the loading state where they will set the value of it to true.

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So when we are getting the top articles, we are no.

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While we know that we are loading something, then we launch our view model scope.

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To launch a call routine.

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So here we're going to use our dispatchers, which is in Scotland call routines, thoughts i o and we

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are setting the news response value to be repository thoughts, good articles.

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So let's import the new model scope and let's import launch, OK, and then once we have the articles

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we're setting, there is loading state again to be not loading.

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So two false.

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So what is going on?

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So we have this main view model, which.

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Is the combination or the connection between the view and the model, so we're using it as a layer in

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between, so to speak.

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And now when we want to get the top articles, we're going to use a cold routine.

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So when we want to use a cold routine, which is our jet articles method.

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So this is a cold routine, and whenever you want to work with cold routines, you need to surround

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them.

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With a view model scope, so you can only launch them inside of the view model scope, you need to say

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on which Fred, you want to run them, so to speak, right of which kind of a threat is not really a

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threat, but something similar.

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And then you can run it and we're running it here.

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We're saying, OK, so the news response state, which is state flow here with whatever the articles

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are.

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And we're also setting this is loading value accordingly.

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So we're going to use this in order to display the loading an indicator so the progress indicator or

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progress bar, so to speak.

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So now in our news app, Katie File.

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Within the navigation method here, we need to make changes because you see we get an error because

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the articles are used differently.

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So here we get articles by category.

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So for now, let's.

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Comment this out.

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So for now, I'm going to comment this out.

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I'm going to do it in a different way later on.

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And let's also fix the error that we have here where the news manager isn't too happy.

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So we need to instead of passing the news manager here.

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Well, actually, it's fine that we passed the news manager, but we need to pass the retrofit service.

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So I don't retrofit service because if you look at our news manager, you see now it needs a new service.

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So the news service itself is this interface.

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And if you want to use this interface, we need to see what's in the news app, Katie.

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So we need to use it by using our API object where we then used our retrofit service.

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This one here, which creates the new service itself.

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Okay.

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And then in our news app, we need to pass something else, so we will now need to also pass the view

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model itself.

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So view model of type main view model will need to be passed at this point as well.

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So we're passing all of these.

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Which now means that we also need to pass it inside of our main screen here.

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So the main screen here at the top when we want to use it will need the main view model as well.

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Like this?

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Let me put it into a separate line like that.

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And then we can pass that to our navigation composable here because at this point, it doesn't get it

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yet.

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So let's pass the view model as well here, which will be our view model, which is the MSI.

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It is the main view model.

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Yes.

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OK, so this main view model that we're passing to it.

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And I'd say, let's make a quick break at this point because we still have quite some steps ahead of

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us, as you see, the news app isn't too happy because the main screen also needs the news model and

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so forth, so we're going to take care of that in a bit.

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So see you in the next video.