# šŸ“š Official Books **URL:** https://forums.kodeco.com/c/books/6.md?page=35 [Latest](https://forums.kodeco.com/latest.md) Ā· [Categories](https://forums.kodeco.com/categories.md) Ā· [Tags](https://forums.kodeco.com/tags.md) **Page:** 36 --- ## [@override as an explicit or an implicit annotation](https://forums.kodeco.com/t/override-as-an-explicit-or-an-implicit-annotation/152557)
**Author:** [@panchoybook](https://forums.kodeco.com/u/panchoybook)\ **Replies:** 6\ **Last updated:** [December 2, 2021, 12:12am UTC](https://forums.kodeco.com/t/override-as-an-explicit-or-an-implicit-annotation/152557 "2021-12-02T00:12:46Z")
I just started reading your book. Great job. I particularly like your code annotations, with notes such as // 1 in the code keyed to the related description in your text: A widgetā€™s build() method is the entry point ā€¦ --- ## [What is the significance of web AR apps?](https://forums.kodeco.com/t/what-is-the-significance-of-web-ar-apps/159087)
**Author:** [@alice7890](https://forums.kodeco.com/u/alice7890)\ **Replies:** 0\ **Last updated:** [December 1, 2021, 12:16pm UTC](https://forums.kodeco.com/t/what-is-the-significance-of-web-ar-apps/159087 "2021-12-01T12:16:36Z")
WebAR apps are better and promising than native apps. Native apps require a lot of space in the device. It has to be installed in the device and canā€™t be operated from any browser. Whereas, Web AR apps are accessible froā€¦ --- ## [Creating a web app (website, not android or iOS app)](https://forums.kodeco.com/t/creating-a-web-app-website-not-android-or-ios-app/158880)
**Author:** [@phi1](https://forums.kodeco.com/u/phi1)\ **Replies:** 1\ **Last updated:** [December 1, 2021, 3:15am UTC](https://forums.kodeco.com/t/creating-a-web-app-website-not-android-or-ios-app/158880 "2021-12-01T03:15:59Z")
In this flutter apprentice book/course, can I create a website? I know dart and flutter can be used to create mobile apps for sometime and I assume this book covers that. I understand in the last 6 months or so dart/Fluā€¦ --- ## [Following chapter 15 and converting the project to use moor is NOT WORKING](https://forums.kodeco.com/t/following-chapter-15-and-converting-the-project-to-use-moor-is-not-working/158960)
**Author:** [@seasonliii](https://forums.kodeco.com/u/seasonliii)\ **Replies:** 2\ **Last updated:** [November 30, 2021, 1:18pm UTC](https://forums.kodeco.com/t/following-chapter-15-and-converting-the-project-to-use-moor-is-not-working/158960 "2021-11-30T13:18:59Z")
I have tried to use the pubspec in the final project as suggesting in another post on the same issue, but itā€™s not helpful. Whatā€™s wrong??? Thereā€™s no proofread process??? I think this book is going to damage the repuā€¦ --- ## [Chapter 15: using GPU draw\_indexed\_primitives for instanced rendering](https://forums.kodeco.com/t/chapter-15-using-gpu-draw-indexed-primitives-for-instanced-rendering/158887)
**Author:** [@lfridael](https://forums.kodeco.com/u/lfridael)\ **Replies:** 4\ **Last updated:** [November 30, 2021, 11:41am UTC](https://forums.kodeco.com/t/chapter-15-using-gpu-draw-indexed-primitives-for-instanced-rendering/158887 "2021-11-30T11:41:18Z")
The approach to ICB command creation from chapter 15 will generate a draw\_indexed\_primitives command for every instance of a given mesh. Now I want to implement instanced rendering, as described in chapter 13. What woulā€¦ --- ## [\[Combine\]throttle bug?](https://forums.kodeco.com/t/combine-throttle-bug/158530)
**Author:** [@anon58552229](https://forums.kodeco.com/u/anon58552229)\ **Replies:** 1\ **Last updated:** [November 29, 2021, 9:03am UTC](https://forums.kodeco.com/t/combine-throttle-bug/158530 "2021-11-29T09:03:40Z")
let subject = PassthroughSubject\() let throttled = subject.throttle(for: .seconds(10), scheduler: DispatchQueue.main, latest: false) throttled.sink(receiveValue: {print($0, Date())}) .store(in: &subsā€¦ --- ## [What is Web AR in layman's language?](https://forums.kodeco.com/t/what-is-web-ar-in-laymans-language/158848)
**Author:** [@alice7890](https://forums.kodeco.com/u/alice7890)\ **Replies:** 0\ **Last updated:** [November 29, 2021, 6:51am UTC](https://forums.kodeco.com/t/what-is-web-ar-in-laymans-language/158848 "2021-11-29T06:51:26Z")
WebAR is also known as web-based augmented reality technology. With this technology, you donā€™t need any mobile apps for viewing the experience. One can access this technology from anywhere with the web browser. They donā€™ā€¦ --- ## [Detect tap on a mesh](https://forums.kodeco.com/t/detect-tap-on-a-mesh/118167)
**Author:** [@raheelahmad](https://forums.kodeco.com/u/raheelahmad)\ **Replies:** 4\ **Last updated:** [April 11, 2021, 11:33pm UTC](https://forums.kodeco.com/t/detect-tap-on-a-mesh/118167 "2021-04-11T23:33:20Z")
I have been trying to detect a tap on a Mesh and failing. Was anyone able to get something like GitHub - metal-by-example/metal-picking: A demonstration of picking (hit-testing) in a 3D scene rendered with Metal work witā€¦ --- ## [I wanted to contribute to the GitHub repo](https://forums.kodeco.com/t/i-wanted-to-contribute-to-the-github-repo/158755)
**Author:** [@iphoneanshul](https://forums.kodeco.com/u/iphoneanshul)\ **Replies:** 0\ **Last updated:** [November 27, 2021, 10:17pm UTC](https://forums.kodeco.com/t/i-wanted-to-contribute-to-the-github-repo/158755 "2021-11-27T22:17:47Z")
Hi, I would like to contribute to the Github repo like updating the code to the new syntax as the current repo code is showing the older syntex of swift UI. --- ## [How to access to a float4 position?](https://forums.kodeco.com/t/how-to-access-to-a-float4-position/158578)
**Author:** [@javi\_aranda](https://forums.kodeco.com/u/javi_aranda)\ **Replies:** 2\ **Last updated:** [November 26, 2021, 1:03am UTC](https://forums.kodeco.com/t/how-to-access-to-a-float4-position/158578 "2021-11-26T01:03:57Z")
Hi! Iā€™m trying to build a cylinder using triangles, but first, I want to make a circle with points to do the base of that cylinder using a for loop from 0 to 360, by 360/number\_of\_divisions, using the sin and cos of the ā€¦ --- ## [Ch13. Even it's a MockService it should be nicer šŸ•µļøā€ā™€ļø](https://forums.kodeco.com/t/ch13-even-its-a-mockservice-it-should-be-nicer/158568)
**Author:** [@alilosoft](https://forums.kodeco.com/u/alilosoft)\ **Replies:** 0\ **Last updated:** [November 25, 2021, 2:42pm UTC](https://forums.kodeco.com/t/ch13-even-its-a-mockservice-it-should-be-nicer/158568 "2021-11-25T14:42:36Z")
In chapter 13 the book introduced a MockService which is great pattern for testing the app without using real API calls, but its implementation contains a lot of annoying duplicated code and itā€™s logic is unnecessary comā€¦ --- ## [Chapter 4,An "Invalid timestamps for HID response delay" thing i met](https://forums.kodeco.com/t/chapter-4-an-invalid-timestamps-for-hid-response-delay-thing-i-met/158563)
**Author:** [@sheffield](https://forums.kodeco.com/u/sheffield)\ **Replies:** 0\ **Last updated:** [November 25, 2021, 1:21pm UTC](https://forums.kodeco.com/t/chapter-4-an-invalid-timestamps-for-hid-response-delay-thing-i-met/158563 "2021-11-25T13:21:31Z")
Hi guys,i met a strange thing when following topic ā€œDebugging views and state changesā€ at page 107,which is in Chapter 4: Testing & Debugging With page 107,first i add this line of code ā€œlet \_ = Self.\_printChanges()ā€ afā€¦ --- ## [Use super.initState() at the start not at the end](https://forums.kodeco.com/t/use-super-initstate-at-the-start-not-at-the-end/158527)
**Author:** [@vadrian](https://forums.kodeco.com/u/vadrian)\ **Replies:** 1\ **Last updated:** [November 25, 2021, 9:03am UTC](https://forums.kodeco.com/t/use-super-initstate-at-the-start-not-at-the-end/158527 "2021-11-25T09:03:11Z")
Hello, Thank you for sharing your book, I am one of those which got a free copy. In your examples with StatefulWidgets, when you override initState() you call super.initState() at the end of the block which is wrong. Iā€¦ --- ## [Render Meshes with Quads Instead of Triangles](https://forums.kodeco.com/t/render-meshes-with-quads-instead-of-triangles/158467)
**Author:** [@unibodydesignn](https://forums.kodeco.com/u/unibodydesignn)\ **Replies:** 1\ **Last updated:** [November 25, 2021, 2:58am UTC](https://forums.kodeco.com/t/render-meshes-with-quads-instead-of-triangles/158467 "2021-11-25T02:58:43Z")
Hi, Iā€™m studying Metal from Metal by Tutorials but I have a very basic question. OpenGL supports drawing objects with quad instead of triangles. e.q the train in the Blender drawn with quad but when obj is imported in Mā€¦ --- ## [8. Deep Links & Web URLs: Connecting the parser to the app router](https://forums.kodeco.com/t/8-deep-links-web-urls-connecting-the-parser-to-the-app-router/158352)
**Author:** [@kingsparadise](https://forums.kodeco.com/u/kingsparadise)\ **Replies:** 5\ **Last updated:** [November 24, 2021, 9:55pm UTC](https://forums.kodeco.com/t/8-deep-links-web-urls-connecting-the-parser-to-the-app-router/158352 "2021-11-24T21:55:54Z")
When i first run the app, I saw this warning message \*\*some input files use or override a deprecated api. \*\* note: recompile with -xlint:deprecation for details. then i run a flutter doctor and it shows this though ā€¦ --- ## [What are the three biggest augmented and virtual reality trends in 2020?](https://forums.kodeco.com/t/what-are-the-three-biggest-augmented-and-virtual-reality-trends-in-2020/155651)
**Author:** [@alice7890](https://forums.kodeco.com/u/alice7890)\ **Replies:** 0\ **Last updated:** [November 2, 2021, 5:39am UTC](https://forums.kodeco.com/t/what-are-the-three-biggest-augmented-and-virtual-reality-trends-in-2020/155651 "2021-11-02T05:39:13Z")
Augmented reality technology has taken over the business so rapidly that it is difficult to portray only 3 trends. The biggest flex of AR technology is for e-commerce websites. Companies like IKEA have established their ā€¦ --- ## [How are streams created ? by controller, by request? and how many times?](https://forums.kodeco.com/t/how-are-streams-created-by-controller-by-request-and-how-many-times/158395)
**Author:** [@ozkayas](https://forums.kodeco.com/u/ozkayas)\ **Replies:** 1\ **Last updated:** [November 23, 2021, 9:25pm UTC](https://forums.kodeco.com/t/how-are-streams-created-by-controller-by-request-and-how-many-times/158395 "2021-11-23T21:25:04Z")
I am confused about the first statement. These will be captured.... for each call Who is requesting the streams and what does being created each time exactly means? :thinking: --- ## [Chapter 34. Quicksort](https://forums.kodeco.com/t/chapter-34-quicksort/158383)
**Author:** [@tibebit](https://forums.kodeco.com/u/tibebit)\ **Replies:** 0\ **Last updated:** [November 23, 2021, 7:19pm UTC](https://forums.kodeco.com/t/chapter-34-quicksort/158383 "2021-11-23T19:19:37Z")
Hello, I have seen that when you illustrate the example with the naive quicksort the initial array taken into consideration is different from the resulting array. I think that is missing a zero inside the sorted array. Mā€¦ --- ## [Find Core Animation book](https://forums.kodeco.com/t/find-core-animation-book/158364)
**Author:** [@lamln](https://forums.kodeco.com/u/lamln)\ **Replies:** 0\ **Last updated:** [November 23, 2021, 3:04pm UTC](https://forums.kodeco.com/t/find-core-animation-book/158364 "2021-11-23T15:04:35Z")
Hi everyone, Iā€™m looking for this book iOS\_Core\_Animation\_Advanced\_Techniques. Anyone have this book? Thank you in advance for your attention to this matter. --- ## [When will the pdf version become available?](https://forums.kodeco.com/t/when-will-the-pdf-version-become-available/142539)
**Author:** [@kumaresanlearner](https://forums.kodeco.com/u/kumaresanlearner)\ **Replies:** 8\ **Last updated:** [November 22, 2021, 11:40pm UTC](https://forums.kodeco.com/t/when-will-the-pdf-version-become-available/142539 "2021-11-22T23:40:16Z")
I purchased the book Dart Apprentice (without any subscription). I read an article that a pdf version will be available. When will the pdf version be released? Thanks. --- ## [Chapter 5 Understanding Widgets Missing pubspec documentation](https://forums.kodeco.com/t/chapter-5-understanding-widgets-missing-pubspec-documentation/157387)
**Author:** [@rpramirez87](https://forums.kodeco.com/u/rpramirez87)\ **Replies:** 3\ **Last updated:** [November 22, 2021, 8:25pm UTC](https://forums.kodeco.com/t/chapter-5-understanding-widgets-missing-pubspec-documentation/157387 "2021-11-22T20:25:25Z")
Iā€™m one of those developers who like to keep my previous projects to start on since I keep my comments on the project based on Ray Wenderlichā€™s numbered format /1 /2 /3 that explains exactly what each line of code does. ā€¦ --- ## [07 Routes and Navigation issue](https://forums.kodeco.com/t/07-routes-and-navigation-issue/158236)
**Author:** [@hongfeiyang](https://forums.kodeco.com/u/hongfeiyang)\ **Replies:** 1\ **Last updated:** [November 22, 2021, 2:18pm UTC](https://forums.kodeco.com/t/07-routes-and-navigation-issue/158236 "2021-11-22T14:18:08Z")
Hi @vincentngo, In chapter 7 routes and navigation, it seems that clicking the ā€˜crossā€™ button on profile page to dismiss the profile page does not fire any ā€˜popā€™ event. Below are the code related to this issue: line 29ā€¦ --- ## [Chapter 32: Heapsort, including the siftDown implementation](https://forums.kodeco.com/t/chapter-32-heapsort-including-the-siftdown-implementation/158238)
**Author:** [@suragch](https://forums.kodeco.com/u/suragch)\ **Replies:** 0\ **Last updated:** [November 22, 2021, 12:19pm UTC](https://forums.kodeco.com/t/chapter-32-heapsort-including-the-siftdown-implementation/158238 "2021-11-22T12:19:07Z")
I hope you all donā€™t mind me opening all these topics. Hopefully they can be useful in the next update. In Chapter 32, Heapsort, you have the code line heap.siftDown(from: 0, upTo: index) and you give a comment: To suā€¦ --- ## [Flutter widgets composability](https://forums.kodeco.com/t/flutter-widgets-composability/158220)
**Author:** [@paristocode](https://forums.kodeco.com/u/paristocode)\ **Replies:** 0\ **Last updated:** [November 22, 2021, 8:48am UTC](https://forums.kodeco.com/t/flutter-widgets-composability/158220 "2021-11-22T08:48:01Z")
Have you ever come across a situation where you followed Flutter syntax correctly with regard to what widgets are allowed to be composed within other widgets, however, only during runtime errors starts to show up. Are tā€¦ --- ## [Issue in Chapter 4 with Xcode 13](https://forums.kodeco.com/t/issue-in-chapter-4-with-xcode-13/158157)
**Author:** [@harmansmith](https://forums.kodeco.com/u/harmansmith)\ **Replies:** 1\ **Last updated:** [November 21, 2021, 11:19pm UTC](https://forums.kodeco.com/t/issue-in-chapter-4-with-xcode-13/158157 "2021-11-21T23:19:53Z")
Hello. Rotation Matrix gives erroneous result. Thatā€™s what it gets in the end. Slightly different from the picture in chapter 4. --- ## [Chapter 12, API errors are not handled correctly. I guess!](https://forums.kodeco.com/t/chapter-12-api-errors-are-not-handled-correctly-i-guess/158175)
**Author:** [@alilosoft](https://forums.kodeco.com/u/alilosoft)\ **Replies:** 2\ **Last updated:** [November 21, 2021, 10:19pm UTC](https://forums.kodeco.com/t/chapter-12-api-errors-are-not-handled-correctly-i-guess/158175 "2021-11-21T22:19:32Z")
The current implementation of ModelConverter.decodeJson() in Chapter 12 uses the following trick to catch API errors, assuming that response.isSuccessful is true if (jsonMap\['status'\] != null) { return response.copyWiā€¦ --- ## [Chapter 15 Moor has been renamed to Drift](https://forums.kodeco.com/t/chapter-15-moor-has-been-renamed-to-drift/156793)
**Author:** [@cyeh1234](https://forums.kodeco.com/u/cyeh1234)\ **Replies:** 4\ **Last updated:** [November 21, 2021, 9:06pm UTC](https://forums.kodeco.com/t/chapter-15-moor-has-been-renamed-to-drift/156793 "2021-11-21T21:06:46Z")
Is there a plan to migrate to drift? Got the following error charlesyeh15@Charless-MacBook-Pro starter % flutter pub run build\_runner build --delete-conflicting-outputs \[INFO\] Generating build scriptā€¦ \[INFO\] Generatiā€¦ --- ## [New content but boring covers](https://forums.kodeco.com/t/new-content-but-boring-covers/157770)
**Author:** [@human4](https://forums.kodeco.com/u/human4)\ **Replies:** 1\ **Last updated:** [November 21, 2021, 6:48am UTC](https://forums.kodeco.com/t/new-content-but-boring-covers/157770 "2021-11-21T06:48:45Z")
I notice all the books are changing their covers. The traditional covers were fun, creative Ray Wenderlinch distinctive. I use to read gladly the reasons for the choice and why it was related to the topic. Now the coversā€¦ --- ## [Flutter, didUpdateWidget()](https://forums.kodeco.com/t/flutter-didupdatewidget/158097)
**Author:** [@paristocode](https://forums.kodeco.com/u/paristocode)\ **Replies:** 1\ **Last updated:** [November 21, 2021, 4:50am UTC](https://forums.kodeco.com/t/flutter-didupdatewidget/158097 "2021-11-21T04:50:42Z")
Why do we need didUpdateWidget(), when we can simply use setState()? Are there cases when the former is called even when the latter is not called? --- ## [How is \_onTappedItem parameter passed?](https://forums.kodeco.com/t/how-is-ontappeditem-parameter-passed/158087)
**Author:** [@fjam](https://forums.kodeco.com/u/fjam)\ **Replies:** 1\ **Last updated:** [November 21, 2021, 4:49am UTC](https://forums.kodeco.com/t/how-is-ontappeditem-parameter-passed/158087 "2021-11-21T04:49:30Z")
In section 2 chapter 3 (basic widgets) the \_onTappedItem function has a Parameter that is taking in an int index, but when we call the \_onTappedItem in the bottomNavigationBar we arenā€™t passing in any parameters to the fā€¦ [Previous page](https://forums.kodeco.com/c/books/6.md?page=34) [Next page](https://forums.kodeco.com/c/books/6.md?page=36)