Pagination from Remote API & Local Cache Using Paging3, Compose and Clean Architecture

[@Rafa-iy2ng]

In 20:12 I would change endOfPaginationReached logic to 'endOfPaginationReached = beers.size() < pageSize' which will save us one extra refresh at the end of the list

[@ubersticks]

At 21:19 the Paging Library pollutes the ViewModel with Entity. Would the use of a Repository help here? The Repository could expose LazyPagingItems to the ViewModel, and it is ok for Repository to know about Entity.

[@rohitnevse5894]

I was waiting for the exact Tutorial on this channel.... And here it is. Philipp is just amazing

[@PhilippLackner]

Happy to help!

[@nijuyonkadesu]

9:15 "Personally I prefer to just have my own solution" Yesh!! in a project of mine, I had to fetch new list of url from server on reaching every 30th image (27 actually). I implemented my own `paging` by using the `position` value from `onBindView()` of ListAdapter. I did that after hearing your words 🥰 because of you I found out that I don't need Paging library 💯

[@k40ol]

Philipp, great course! Thank you for uploading & sharing! Wanted to mention, to avoid exposing your BeerEntity to UI layer, consider separating cache/caching to its own db. i.e. BeerEntity becomes BeerCatalogItem (this is the cached entity in its own DB). You can always include more extension functions / mappers to get a clean Domain object out to UI layer. Pros: - simplicity in caching - simpler schema migration Cons: - another DB - more space for cached content Awesome courses! Thank you again! (Will buy one soon to support you!)

[@MxMayers]

I have a problem with the domain layer interface, PagingSource and its data layer implementation because dao in the data layer requires PagingSource. As I know the domain layer should not contain data layer entities, how to implement the domain layer interface in the data layer?

[@theophilus494]

thank you boss.. I remembered contacting you on your instagram DM on this topic.. and here we are.. God bless you greatly.. really appreciate you...

[@PhilippLackner]

Happy to help!

[@mesutemrecelenk5447]

This tutorial is an artwork😊 thanks Phlipp

[@kuana9961]

Thank you very much for the live coding tutorial.🙏 It's simple, easy to understand, and very rewarding.

[@ezriouil]

the best channel in youtube from morocco

[@antonyfilochowski335]

thank you helped me overcome a couple of obstacles i was encountering

[@AlanBartholomew-h7o]

Philipp, at 31:50 in the video you select "items(items: LazyPagingItems", however it does not appear for me in the list. No matter what I select I get an error when hovering over (beers) that states Type Mismatch Required: Int, Found: lazyPagingItems . This also happens if I use the app source code from the Github site. Could the problem be that I am using Android Studio Flamingo | 2022.2.1 Patch 2

[@limtis]

You can use any other items() items(beers.itemCount) { index -> val beer = beers[index] ... }

[@germenwong]

I also encountered the same problem， You can modify according to the pagination library version of the video, and then

[@entchannel]

Thank you so much! It helped me to get the json file. But I’m dealing with json that contain two object first is information about current page, next page url and previous page url and another one is list with the objects that I want to display in recycle view. What should I do? Do I need a data class for each object?

[@ygorfrazao4420]

Great tutorial, once again. I am wondering if we can wrap the pager inside a repository, or, even, an use case and then inject these in our viewmodel, what do you think?

[@ngomdecadetkamdaou3464]

I enjoyed the video. But I noticed that in the data package, there is a remote mediator that makes the API call and has some business logic. Does the remote mediator replace the repository and the use case at the same time when referring to clean architecture?

[@udioshi7799]

Thank you Philipp for the tutorial, Your mediator loads 4 pages (80 beers) at startup before scrolling

[@reyjohn88]

How did you solve this? It happens in my implementation too?

[@udioshi7799]

@@reyjohn88 didn’t solve yet

[@jam4l]

Great video, Thanks Philipp 👏

[@pereyrarg11]

Awesome! it was a good introduction to Paging

[@artyommukovozchik7165]

Great as always and so amazing tutorial. Keep doing such useful videos!

[@mircodev]

Thanks for this perfect explanation!

[@PhilippLackner]

Glad it was helpful!

[@path_ethics]

Thanks for the video, you probably got there by now but at 21:27 to solve this (if I understood correctly), instead of having the pager inside your viewModel, you can have another class in between like a dbRepository or a useCase or both. In that repository/usecase you return a Pager(...).flow.map(), and in there you map the PagingData items to your UI model.

[@mubaraknative]

How Phillip you find these types of algorithms 17:25

[@trocchiettoski]

Suggestion, an app with a shared view model for a basket, and some payment method. Philip you rock

[@nicholasferrara8028]

Keep up the great work!

[@LEEJIHUN]

Thank you for the great video! If the description of the beer is long, I want to center the beer image on the card, can you tell me how I can center it?

[@berkc5323]

Hello Philipp, thanks for the amazing videos. I have a question, let's say I'm fetching some data from the api and want to keep it somewhere that multiple viewModels can reach. But I don't want to fetch the data again every time it needs to be used. What is the best way to do it without breaking the clean architecture? Which layer of clean architecture I should keep them? Should I keep the variables in a companion object (I don't want it) or maybe in a repository and inject that repository to the viewModels that need to use it. I don't want to use a BaseViewModel also because I have so many of those variables :) thank you.

[@smartkidsru]

Philipp, thanks for your brilliant work! It would be interesting to know how to remove the item from the list by item's id without refreshing the whole list? Looks like it is difficult to implement using compose paging3 library...

[@DaleHawkins]

Nice job. Thank you!

[@ntikomathaba2662]

Awesome video Phillip, as always. 👏🏾 If you wanted to group the data into different sections, how would you go about doing that?

[@JahangirJadi]

Hi Philipp. First of all, thank you for this amazing tutorial. I have a question. What if I need to update the paging list? For example, update some item at position. How can I achieve this?

[@adityarathi8309]

Hi Phillip, Great Tutorial, Learning a lot. I had a question, is it possible to get the total item count fetched till the current time in RemoteMediator? I wanted to understand a use case when id is not exactly the number of items fetched?

[@formatBCE]

If you have page size 10, and already have 2 pages loaded, and there's 29 beers in list, following will happen: - paging lib loads page 3 - entities count is 29 - next page = 29 / 10 + 1 = 2 + 1 = 3 - end of pagination not reached - paging lib loads page 3 - upsert updates last 9 items - back to start

[@bdsnarola]

In this, I notice that the pager calls API for 3-4 pages on app startups. And I also want to include that when the app needs new data on scrolling that time also it calls API for 2 pages at a time. Can we manage it to call API only one time at a time?

[@Rafa-iy2ng]

I always make mappers as `val` extensions. Are there any disadvantages of this solution?

[@sagarprajapati8769]

​@PhilippLackner please create and add blog about this topic.

[@renzcarlosalanga6077]

It would be awesome if you can make a CRUD operations with Paging 3

[@Leon-un2ii]

Thanks for this great tutorial! One question: why you are using retrofit and not ktor?

[@germenwong]

Hi Philip， Can you explain the relationship between PagingSource and RemoteMediator

[@anorov_hasan]

thanks , amazing works great , can you also share your experiences on using markdown in compose

[@pranavsubramanian2549]

Hi Philipp, I am trying to list out all the items available in Firebase Storage, cache and display it. It doesn't seem to work and I am stuck. What should I do? By the way, your videos are amazing and any video I need on Android Development, I come to this channel first and I mostly get the answers. Great work!

[@janbrs7040]

My daily dose of Android Stuffs

[@algo_chronicles]

Violation of clean architecture principal but video is good❤

[@seftiannurfaozy2918]

thank you phillip

[@AbdulelahAGR]

Thank you for the video

[@roshkaalex]

Thank you. Will be pagination for KMM?

[@KunalGoyal]

Punk API stopped working, getting 404

[@icycleragon]

Same here

[@siva_subramaniam]

Thank you so much. I have a doubt. Why didn't you include the "androidx.room:room-runtime:$room_version" dependency? Isn't it necessary?

[@zynastor1]

This guy is amazing

[@NZBurmeseLink]

Hello Philipp, I would like to know about all of your courses. Is there a discount available if I purchase all of them?

[@dmytrodolotov9723]

Hi Philipp, thank you for great tutorial. In the latest version of compose, LazyColumn items() function can no longer accept LazyPagingItems as an argument. What is the best way to solve this issue?

[@KunalGoyal]

items(beers.itemCount){index - > val beer = beers[index]}..Use this

[@mikelantzelo]

LazyColumn items not showing LazyPagingItems choice. What am i missing? Can someone help?

[@symekoo7]

I have same issue unfortunatelly. Did you manage to fix it?

[@jishnugoyal4397]

How to cache the images? Do you think you would cover the same?

[@MatrixAppDev]

hello philip always thank you for the video Usually, external API and internal room data are often used in the structure of viewmodel - usecase - repository - dao, but why not use that structure when using paging?

[@ericwathome783]

you just make everything simple

[@vazhakentchiashvili2198]

Amazing!❤

[@qweqwe2589]

Can you please make a tutorial about how to write back navigation that also supports also api 33? Because after api 33 there is someting new and it's really hard to find on the internet how to implement it perfectly.

[@proandroiddevir]

Hi Mr lackner . Can you teach crashlytics?

[@chulgunsirru]

thanks for video!

[@JohanAlbrectsen]

Good video, but you should also include with cursor pagination logic, as it's the superior pagination type.

[@hanasakura4541]

Great. Thanks a lot

[@ubersticks]

Hey Phillip - good stuff! You were down on Paging library one year ago and actually had an excellent tutorial video showing how to do it yourself. What changed your mind about Paging Library?

[@PhilippLackner]

I still use it, but many people wanted a paging tutorial and if you page with a cache it makes things a lot easier

[@nurkholiq1931]

I wonder to imagine what happens to the loaded page if in the middle scroll we change the API query?

[@path_ethics]

If I need to pass more parameters to remote api, like for example, if a user can select a parameter to filter the api responses, where do I pass those filter values for them to get to the api?

[@MyHobbies-qh8pg]

on your repository inside remote mediator pass query String fun getAllUsers( query: String ): Flow { val pagingSourceFactory = { database.userDao().getAllUsers() } return Pager( config = PagingConfig(pageSize = ITEMS_PER_PAGE), remoteMediator = UsersRemoteMediator( api = api, usersDatabase = database, query = query ), pagingSourceFactory = pagingSourceFactory ).flow } on your remote mediator lass UsersRemoteMediator( private val api: HomeScreenApi, private val usersDatabase: UserDatabase, private val query: String ) : RemoteMediator() { ****** }

[@freshtechtips]

Philipp why you still use retrofit? I thought you said you love ktor more and prefer it

[@zulhijananda5772]

How to handle query situation? my project works with no query, how to make the paging based on query params?

[@CodingZest]

It might be not the right question, but I really want to know which theme are you using in your Android Studio?

[@germenwong]

xcode-dark

[@CodingZest]

@@germenwongthanks for reply

[@TuanPhanVan-s7v]

Thank you

[@John-qt6qk]

Can I use it with firestore?

[@amateur_gamer101]

i have a question about pagination. Can u use it for all APIs or does the API have to be built in a way that supports it before you can use it?

[@PhilippLackner]

The API needs to support it

[@amateur_gamer101]

@@PhilippLackner lets say the API does not support it, saving the unpaginated response to room and paginating from room is the right way to go?

[@PhilippLackner]

@@amateur_gamer101 has a little impact but the longest time is needed to do the network call, not to load from the local db

[@gaoliang1368]

how drag drop resort item

[@Adam0001]

Great 👏

[@AhmedElsayed-ed9ts]

I can't find the items of lazypagingadapter

[@sidbot9622]

same for me did you figure it out??

[@voidpointer398]

After going through different other articles and codebases, I have found that you cannot abstract out the database details from the ui layer, the pager object tightly couples the ui layer to the paging3 library. If anyone else found a solution to this please tell

[@SudhanshuKumar-xy6xv]

Looking for the same

[@reyjohn88]

I implemented this in one of my project, but don't know why it always loads first 4 pages everytime the screen loads. Anyone have any solution for that?

[@Shubhammonga242s]

Amazing

[@proandroiddevir]

Thanks for this video👏👏👏👏👏👏👏🙏🙏🙏🙏👍👍👍💪💪💪💪💪💪💪

[@olegleonov1310]

I think there is one more condition when `endPaginationReached` could be `true`. It's `state.config.pageSize` > beers.size(). It means that we got fewer items than we should have on the page and it was the last page.

[@ahmedrashed2587]

Will the courses be delivered to me like physically or I'll get them online

[@PhilippLackner]

It's all online

[@aminsakha155]

The deployment could not be found on Vercel :)

[@AmitKumar-pw1ln]

Great

[@codeventure23]

Coupon not working for me

[@bilmiyorum06]

Using entities instead of UI models in ViewModel is unacceptable. You made it short so that people wouldn't get bored watching the video, but we could have done this in the Repository layer.

[@andreaslinis1586]

Yes but why

[@shalenmathew]

I didn't get can u explain?

[@mtanve2319]

Anyone trying this in 2024, the PunkAPI has been shut down. Just spent 2 hours on this for it to not work.

[@imamyusupbachtiar5461]

Nice,

[@TheZaurHasanov]

❤

[@sijanneupane]

done an' dusted!

[@moldovanpeter5123]

Nice Vid but in the end it still an overhead to implement pagination and also from Archi perspective, I would not use it, and still not using it because of this.

[@Revitalish]

it's not clear at all why there should be both Beer model and simple Beer data class that looks exactly the same. and what is this beer.tobeerentity and vise versa for? you don't explain crucial things..

[@gaoliang1368]

It would be awesome if you can make a CRUD operations with Paging 3