# šŸ“š Official Books **URL:** https://forums.kodeco.com/c/books/6.md?page=39 [Latest](https://forums.kodeco.com/latest.md) Ā· [Categories](https://forums.kodeco.com/categories.md) Ā· [Tags](https://forums.kodeco.com/tags.md) **Page:** 40 --- ## [What are some good resources for learning about augmented reality?](https://forums.kodeco.com/t/what-are-some-good-resources-for-learning-about-augmented-reality/154689)
**Author:** [@alice7890](https://forums.kodeco.com/u/alice7890)\ **Replies:** 0\ **Last updated:** [October 25, 2021, 9:17am UTC](https://forums.kodeco.com/t/what-are-some-good-resources-for-learning-about-augmented-reality/154689 "2021-10-25T09:17:17Z")
If you seriously want to learn about augmented reality then you should try getting some hands-on experience. The practical knowledge will help you understand it better. The experiences that you can create by using AR tecā€¦ --- ## [Chapter 9 Challenge 3](https://forums.kodeco.com/t/chapter-9-challenge-3/154668)
**Author:** [@suragch](https://forums.kodeco.com/u/suragch)\ **Replies:** 0\ **Last updated:** [October 25, 2021, 7:28am UTC](https://forums.kodeco.com/t/chapter-9-challenge-3/154668 "2021-10-25T07:28:44Z")
In Chapter 9 Challenge 3 you create a TraversableBinaryNode abstract class but do you actually use it in your AvlTree class? Itā€™s not clear from the explanation how it is applied (but that may be because I donā€™t know Kotā€¦ --- ## [Chapter 6: simple question on usage of 'const' on home.dart](https://forums.kodeco.com/t/chapter-6-simple-question-on-usage-of-const-on-home-dart/154536)
**Author:** [@helvecio](https://forums.kodeco.com/u/helvecio)\ **Replies:** 2\ **Last updated:** [October 24, 2021, 6:22pm UTC](https://forums.kodeco.com/t/chapter-6-simple-question-on-usage-of-const-on-home-dart/154536 "2021-10-24T18:22:18Z")
Hi, all. Very specific here, but could anyone explain why the ā€˜constā€™ is needed for GroceryScreen(), but neither for ExploreScreen() nor for RecipesScreen() on ā€˜\_HomeState extendsā€™ on home.dart? Thanks, H --- ## [Lost with callbacks in Chapter 6.9](https://forums.kodeco.com/t/lost-with-callbacks-in-chapter-6-9/154496)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 7\ **Last updated:** [October 24, 2021, 5:13pm UTC](https://forums.kodeco.com/t/lost-with-callbacks-in-chapter-6-9/154496 "2021-10-24T17:13:36Z")
In chapter 6.9, Iā€™m getting lost ā€¦ probably because of my limited understanding of Dart and no real experience with OO programming ā€¦ can someone help me determine how to interpret these 2 lines? Also, at what point shouā€¦ --- ## [Chapter 6 Bug ( grocery\_list\_screen)](https://forums.kodeco.com/t/chapter-6-bug-grocery-list-screen/154535)
**Author:** [@lediomalasi](https://forums.kodeco.com/u/lediomalasi)\ **Replies:** 2\ **Last updated:** [October 24, 2021, 5:27am UTC](https://forums.kodeco.com/t/chapter-6-bug-grocery-list-screen/154535 "2021-10-24T05:27:59Z")
mport ā€˜package:flutter/material.dartā€™; import ā€˜ā€¦/components/grocery\_tile.dartā€™; import ā€˜ā€¦/models/models.dartā€™; import ā€˜grocery\_item\_screen.dartā€™; import ā€˜ā€¦/models/grocery\_item.dartā€™; class GroceryListScreen extends ā€¦ --- ## [Solid examples for using StripeKit package](https://forums.kodeco.com/t/solid-examples-for-using-stripekit-package/154078)
**Author:** [@wtj123](https://forums.kodeco.com/u/wtj123)\ **Replies:** 2\ **Last updated:** [October 24, 2021, 1:09am UTC](https://forums.kodeco.com/t/solid-examples-for-using-stripekit-package/154078 "2021-10-24T01:09:20Z")
Iā€™ve built an E-commerce store web site using vapor and Iā€™d like to use StripeKit package. After viewing the StripeKit on the GitHub, I found the description of using the API is not very clear and I had no idea how to inā€¦ --- ## [I lost my ability to create notes for this book](https://forums.kodeco.com/t/i-lost-my-ability-to-create-notes-for-this-book/154501)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 0\ **Last updated:** [October 23, 2021, 3:31pm UTC](https://forums.kodeco.com/t/i-lost-my-ability-to-create-notes-for-this-book/154501 "2021-10-23T15:31:21Z")
Up until today (Saturday 10/23), I was able to highlight text and create notes in the book app here. But today, highlighting doesnā€™t bring up the tooltip anymore. Iā€™m running Windows 10 and yes, I rebooted to see if thaā€¦ --- ## [Firts time coding in life](https://forums.kodeco.com/t/firts-time-coding-in-life/152774)
**Author:** [@iadanish](https://forums.kodeco.com/u/iadanish)\ **Replies:** 7\ **Last updated:** [October 22, 2021, 10:04am UTC](https://forums.kodeco.com/t/firts-time-coding-in-life/152774 "2021-10-22T10:04:41Z")
Hi I am new to development life, I havenā€™t code before this and I am starting learning Flutter to develop apps for my own startups, I have a window system, how I can get started? --- ## [Generate mesh using custom vertex data](https://forums.kodeco.com/t/generate-mesh-using-custom-vertex-data/149290)
**Author:** [@lanhaide](https://forums.kodeco.com/u/lanhaide)\ **Replies:** 11\ **Last updated:** [October 23, 2021, 4:23am UTC](https://forums.kodeco.com/t/generate-mesh-using-custom-vertex-data/149290 "2021-10-23T04:23:16Z")
Hi. Iā€™m new to Metal/iOS and Iā€™m trying to generate mesh using custom vertex data. In my demo project, the vertex position data is stored in test.bin, and index data is saved in body-index.txt. I tried to parse vertexā€¦ --- ## [Chapter 3 getting started](https://forums.kodeco.com/t/chapter-3-getting-started/154183)
**Author:** [@ofiroz91](https://forums.kodeco.com/u/ofiroz91)\ **Replies:** 4\ **Last updated:** [October 22, 2021, 3:34pm UTC](https://forums.kodeco.com/t/chapter-3-getting-started/154183 "2021-10-22T15:34:35Z")
ā€œStart by downloading this chapterā€™s project from the book materials repoā€ There seem to be more then one file on the repo that hold ā€œstarterā€ Can someone better explain " Locate the projects folder and open starter . Iā€¦ --- ## [Chapter 6.6 Do I understand ... Adding a TabManager consumer?](https://forums.kodeco.com/t/chapter-6-6-do-i-understand-adding-a-tabmanager-consumer/154279)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 5\ **Last updated:** [October 22, 2021, 1:26pm UTC](https://forums.kodeco.com/t/chapter-6-6-do-i-understand-adding-a-tabmanager-consumer/154279 "2021-10-22T13:26:52Z")
I want to see if I understand the below code in BottomNavigationBar() ā€¦ If I do, Iā€™ll be amazed :grinning: ā€¦ How close am I? Immediately after pressing one of the tabs at the bottom of the screen, the currentIndex proā€¦ --- ## [Set-up advice for Android Studio](https://forums.kodeco.com/t/set-up-advice-for-android-studio/154317)
**Author:** [@carlstep333](https://forums.kodeco.com/u/carlstep333)\ **Replies:** 4\ **Last updated:** [October 22, 2021, 11:58am UTC](https://forums.kodeco.com/t/set-up-advice-for-android-studio/154317 "2021-10-22T11:58:03Z")
Hi, hoping someone can help. Iā€™m using Android Studio to work through the tutorials. When I type in the code I get this overlay popping up (see image). Iā€™m sure it is helpful but the pop-up is so big that it covers mosā€¦ --- ## [What is the difference of Stream and Provider?](https://forums.kodeco.com/t/what-is-the-difference-of-stream-and-provider/154320)
**Author:** [@minuth](https://forums.kodeco.com/u/minuth)\ **Replies:** 1\ **Last updated:** [October 22, 2021, 6:33am UTC](https://forums.kodeco.com/t/what-is-the-difference-of-stream-and-provider/154320 "2021-10-22T06:33:50Z")
Since we can use both of them to manage the state of app. --- ## [Chapter 12 - no search results in app](https://forums.kodeco.com/t/chapter-12-no-search-results-in-app/154282)
**Author:** [@viride](https://forums.kodeco.com/u/viride)\ **Replies:** 2\ **Last updated:** [October 22, 2021, 6:23am UTC](https://forums.kodeco.com/t/chapter-12-no-search-results-in-app/154282 "2021-10-22T06:23:56Z")
Hi, I am running chapter 12 final solution, I added my appId and apiKey, but I got no results in app, and error in socket\_patch.dart (line 238, error: ArgumentError (Invalid argument(s): Invalid internet address api.edamā€¦ --- ## [Chap 6: Interactive Widgets - grocery\_tile.dart](https://forums.kodeco.com/t/chap-6-interactive-widgets-grocery-tile-dart/154241)
**Author:** [@arupsarkar](https://forums.kodeco.com/u/arupsarkar)\ **Replies:** 4\ **Last updated:** [October 22, 2021, 1:20am UTC](https://forums.kodeco.com/t/chap-6-interactive-widgets-grocery-tile-dart/154241 "2021-10-22T01:20:06Z")
I am not getting the small fruits and veggies icon, am I missing anything ? --- ## [@ChopperApi(): adding another path to the class](https://forums.kodeco.com/t/chopperapi-adding-another-path-to-the-class/154285)
**Author:** [@alijaber](https://forums.kodeco.com/u/alijaber)\ **Replies:** 0\ **Last updated:** [October 21, 2021, 8:54pm UTC](https://forums.kodeco.com/t/chopperapi-adding-another-path-to-the-class/154285 "2021-10-21T20:54:42Z")
Hello team, in the book, in the chopper chapter, you added the following: abstract class RecipeService extends ChopperService { @Get(path: 'search') Future\\>\> queryRecipes( @Queā€¦ --- ## [Chapter 6 Having trouble understanding the Provider Package](https://forums.kodeco.com/t/chapter-6-having-trouble-understanding-the-provider-package/154267)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 1\ **Last updated:** [October 21, 2021, 7:49pm UTC](https://forums.kodeco.com/t/chapter-6-having-trouble-understanding-the-provider-package/154267 "2021-10-21T19:49:32Z")
How important is it for us to understand the Provider package in Chapter 6? I got pretty lost trying to understand it. I felt like I was just copying / pasting without understanding it. Do you think in Chapter 13 State ā€¦ --- ## [Flutter Apprentice - Chapter 2 - Section \`Add GestureDetector\`](https://forums.kodeco.com/t/flutter-apprentice-chapter-2-section-add-gesturedetector/152427)
**Author:** [@aifx4intel](https://forums.kodeco.com/u/aifx4intel)\ **Replies:** 7\ **Last updated:** [October 21, 2021, 3:21pm UTC](https://forums.kodeco.com/t/flutter-apprentice-chapter-2-section-add-gesturedetector/152427 "2021-10-21T15:21:34Z")
Easy time i add this to where i think it should be the code afterwards gets greyed out. Can someone please assist me with this placement error? Thank you. --- ## [In 6.4 is there a reason we used fontSize instead of Theme?](https://forums.kodeco.com/t/in-6-4-is-there-a-reason-we-used-fontsize-instead-of-theme/154066)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 2\ **Last updated:** [October 21, 2021, 5:04am UTC](https://forums.kodeco.com/t/in-6-4-is-there-a-reason-we-used-fontsize-instead-of-theme/154066 "2021-10-21T05:04:15Z")
In 6.4 is there a reason we used fontSize instead of Theme? const Text( 'No Groceries', style: TextStyle(fontSize: 21.0), ), vs const Text( 'No Groceries', ā€¦ --- ## [Child NavigationView issue with iOS 15](https://forums.kodeco.com/t/child-navigationview-issue-with-ios-15/154090)
**Author:** [@shadowsheep](https://forums.kodeco.com/u/shadowsheep)\ **Replies:** 2\ **Last updated:** [October 21, 2021, 1:42am UTC](https://forums.kodeco.com/t/child-navigationview-issue-with-ios-15/154090 "2021-10-21T01:42:26Z")
Hi guys! Iā€™m trying the sample code with Xcode 13. Iā€™ve found this issue on tree view child NavigtionView as described here swiftui - Child NavigationView doesn't honor modifiers on iOS 15 - Stack Overflow. I cannot thinā€¦ --- ## [Chapter 6.4 Best Practice for use of inline constants vs file containing constants?](https://forums.kodeco.com/t/chapter-6-4-best-practice-for-use-of-inline-constants-vs-file-containing-constants/154060)
**Author:** [@jefff9511](https://forums.kodeco.com/u/jefff9511)\ **Replies:** 1\ **Last updated:** [October 20, 2021, 1:33pm UTC](https://forums.kodeco.com/t/chapter-6-4-best-practice-for-use-of-inline-constants-vs-file-containing-constants/154060 "2021-10-20T13:33:58Z")
In Chapter 6.4, where we say // 1 Flexible( // 2 child: AspectRatio( aspectRatio: 1 / 1, child: Image.asset('assets/fooderlich\_assets/empty\_list.png'), ), ), would best practice be to have a separate consā€¦ --- ## [Git Error when cloning flta-materials](https://forums.kodeco.com/t/git-error-when-cloning-flta-materials/153742)
**Author:** [@sakhilemamba](https://forums.kodeco.com/u/sakhilemamba)\ **Replies:** 6\ **Last updated:** [October 20, 2021, 10:25am UTC](https://forums.kodeco.com/t/git-error-when-cloning-flta-materials/153742 "2021-10-20T10:25:15Z")
Hello everyone, Please help, I keep getting the following error when I try to clone the flta-materials repository onto my local machine: Git: remote: Enumerating objects: 7950, done. --- ## [Whatis the meaning of the double question mark when we are getting data from the future builder](https://forums.kodeco.com/t/whatis-the-meaning-of-the-double-question-mark-when-we-are-getting-data-from-the-future-builder/153886)
**Author:** [@sheldoni](https://forums.kodeco.com/u/sheldoni)\ **Replies:** 6\ **Last updated:** [October 20, 2021, 9:45am UTC](https://forums.kodeco.com/t/whatis-the-meaning-of-the-double-question-mark-when-we-are-getting-data-from-the-future-builder/153886 "2021-10-20T09:45:56Z")
Someone to explain to me the logic behind the double question marks when we are getting data from our future to build the grid view. --- ## [Use of Equatable in Chapter 13 for non immutable classes](https://forums.kodeco.com/t/use-of-equatable-in-chapter-13-for-non-immutable-classes/153956)
**Author:** [@salmankhilji](https://forums.kodeco.com/u/salmankhilji)\ **Replies:** 1\ **Last updated:** [October 20, 2021, 9:21am UTC](https://forums.kodeco.com/t/use-of-equatable-in-chapter-13-for-non-immutable-classes/153956 "2021-10-20T09:21:34Z")
According to the documentation of the Equatable package: Equatable is designed to only work with immutable objects so all member variables must be final (This is not just a feature of Equatable - overriding a hashCode ā€¦ --- ## [How can schools benefit from AR technology?](https://forums.kodeco.com/t/how-can-schools-benefit-from-ar-technology/153994)
**Author:** [@alice7890](https://forums.kodeco.com/u/alice7890)\ **Replies:** 0\ **Last updated:** [October 20, 2021, 6:28am UTC](https://forums.kodeco.com/t/how-can-schools-benefit-from-ar-technology/153994 "2021-10-20T06:28:57Z")
Augmented reality has already taken over the world through various advancements in the way of its presentation. Now more than ever, people think VR is greater and superior to AR which is entirely false. AR technology canā€¦ --- ## [How can I choose which GPU Create ML will use?](https://forums.kodeco.com/t/how-can-i-choose-which-gpu-create-ml-will-use/153981)
**Author:** [@yonibentov](https://forums.kodeco.com/u/yonibentov)\ **Replies:** 0\ **Last updated:** [October 20, 2021, 4:46am UTC](https://forums.kodeco.com/t/how-can-i-choose-which-gpu-create-ml-will-use/153981 "2021-10-20T04:46:15Z")
Hello, I have some eGPUs hooked up to my iMac Pro, but when I try to train data using Create ML (e.g., from Chapter 3), I see in the activity monitor that only the built-in Pro Vega 64X is being used. I tried to check ā€¦ --- ## [Errata for Advanced Git 2nd Edition](https://forums.kodeco.com/t/errata-for-advanced-git-2nd-edition/152741)
**Author:** [@jellodiil](https://forums.kodeco.com/u/jellodiil)\ **Replies:** 2\ **Last updated:** [October 19, 2021, 9:27pm UTC](https://forums.kodeco.com/t/errata-for-advanced-git-2nd-edition/152741 "2021-10-19T21:27:00Z")
Creating this topic to catch any typos and bugs in the 2nd Edition of Advanced Git. --- ## [Section 1 : 2.2 Making the app yours](https://forums.kodeco.com/t/section-1-2-2-making-the-app-yours/153909)
**Author:** [@nabilnazar](https://forums.kodeco.com/u/nabilnazar)\ **Replies:** 0\ **Last updated:** [October 19, 2021, 5:49pm UTC](https://forums.kodeco.com/t/section-1-2-2-making-the-app-yours/153909 "2021-10-19T17:49:21Z")
\> the below code is not working for me, Still the appbar color remains blue and white theme: theme.copyWith( colorScheme: theme.colorScheme.copyWith( primary: Colors.grey, secondary: Coā€¦ --- ## [Run unit test with Combine for networking Layer](https://forums.kodeco.com/t/run-unit-test-with-combine-for-networking-layer/153862)
**Author:** [@swiftios](https://forums.kodeco.com/u/swiftios)\ **Replies:** 0\ **Last updated:** [October 19, 2021, 11:09am UTC](https://forums.kodeco.com/t/run-unit-test-with-combine-for-networking-layer/153862 "2021-10-19T11:09:15Z")
Hello , I would like to know how I can run a unit test for the method request in case of success without making a real request to endPoint. this the method makeRequest itā€™s takes as parameter URLComponent and return Anā€¦ --- ## [Possible Error in Chapter 4.5: Widgets](https://forums.kodeco.com/t/possible-error-in-chapter-4-5-widgets/153829)
**Author:** [@plplyons72](https://forums.kodeco.com/u/plplyons72)\ **Replies:** 2\ **Last updated:** [October 19, 2021, 7:59am UTC](https://forums.kodeco.com/t/possible-error-in-chapter-4-5-widgets/153829 "2021-10-19T07:59:33Z")
REPRO: Nav to chapter 4.5 Find the sub header/title ā€˜Examining the widget treeā€™ Nav to the third image below this header. Expected: State (\_isFavorited = true) Actual: State (\_isFavorited = false) [Previous page](https://forums.kodeco.com/c/books/6.md?page=38) [Next page](https://forums.kodeco.com/c/books/6.md?page=40)