投稿時間:2021-11-11 00:41:28 RSSフィード2021-11-11 00:00 分まとめ(41件)

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IT	気になる、記になる…	Microsoft、公式ストアで｢いい買い物の日キャンペーン｣のセールを開始 − 対象のSurfaceなどが特価に	https://taisy0.com/2021/11/10/148567.html	microsoft	2021-11-10 14:09:08
Google	カグア！Google Analytics 活用塾:事例や使い方	病院で200万円の測定器で国保630円で筋肉量測定のInBody測定をしてきたら足の筋肉量が激減しててやばかった。すぐにウォーキングやインナーマッスルを鍛えるティラピスはじめました。	https://www.kagua.biz/health/hernia/20211110a3.html	病院で万円の測定器で国保円で筋肉量測定のInBody測定をしてきたら足の筋肉量が激減しててやばかった。	2021-11-10 14:00:49
AWS	AWS Open Source Blog	Performing canary deployments and metrics-driven rollback with Amazon Managed Service for Prometheus and Flagger	https://aws.amazon.com/blogs/opensource/performing-canary-deployments-and-metrics-driven-rollback-with-amazon-managed-service-for-prometheus-and-flagger/	Performing canary deployments and metrics driven rollback with Amazon Managed Service for Prometheus and FlaggerThis post was written by Kevin Bell and Stefan Prodan Canary deployments are a popular tool to reduce risk when deploying software by exposing a new version to a small subset of traffic before rolling it out more broadly Creating the machinery to do this kind of controlled rollout and monitoring for possible problems and …	2021-11-10 14:56:29
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	html初心者です。	https://teratail.com/questions/368735?rss=all	html初心者です。	2021-11-10 23:59:35
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	A3RTの自動応答をしようとしたところ、エラーが出ました（python）	https://teratail.com/questions/368734?rss=all	ARTの自動応答をしようとしたところ、エラーが出ましたpython前提・実現したいことmacのターミナルで下記のpythonコードを実行したところ、エラーが出ました。	2021-11-10 23:59:03
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	PHP:接続はできるのですが、読み込めはしないらしいです...泣	https://teratail.com/questions/368733?rss=all	PHP接続はできるのですが、読み込めはしないらしいです泣環境デバイスgtmacbooknbspair使用ツールgtMAMP使用言語gtphp使用DBgtMySQL問題点現在データベースとwebページを繋ぐのに苦労しています。	2021-11-10 23:58:58
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	Mysql Empty set, 1 warning	https://teratail.com/questions/368732?rss=all	MysqlEmptysetwarningMysqlnbsp初心者で勉強中のものです。	2021-11-10 23:58:34
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	JavaScript relaceAllでバラバラの乱数を発生させることは不可能ですか	https://teratail.com/questions/368731?rss=all	floor	2021-11-10 23:58:01
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	ワードプレスを簡単インストール(x サーバー）で上書きしてしまい戻せません。	https://teratail.com/questions/368730?rss=all	ワードプレスをデータが入っているフォルダに上書きしてしまい元に戻せなくなってしまいました。	2021-11-10 23:50:33
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	最小二乗法を用いて直線フィッティングしようとしていますがエラーが出て困っています。	https://teratail.com/questions/368729?rss=all	最小二乗法を用いて直線フィッティングしようとしていますがエラーが出て困っています。	2021-11-10 23:36:49
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	サーブレット内のJsoupで起こるエラー（HTTPステータス 500 – Internal Server Error）	https://teratail.com/questions/368728?rss=all	サーブレット内のJsoupで起こるエラーHTTPステータスInternalServerError前提・実現したいことjspからサーブレットにhtmlファイルをアップし、そのhtmlファイルをjsoupで解析したい。	2021-11-10 23:36:30
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	pythonのwebフレームワーク”bottle”でBasic認証を実現したい※シングルファイル	https://teratail.com/questions/368727?rss=all	pythonのwebフレームワークbottleでBasic認証を実現したい※シングルファイル前提・実現したいことpythonのwebフレームワークのbottleでBasic認証を実現したいです。	2021-11-10 23:31:41
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	dfから二つの条件を満たす数値の出現数を知りたい	https://teratail.com/questions/368726?rss=all	dfから二つの条件を満たす数値の出現数を知りたい前提・実現したいことdfは、以下のような、年間の波高と周期の時系列データです。	2021-11-10 23:31:17
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	計算とlf文の混合はどうやって書けばよろしいでしょうか	https://teratail.com/questions/368725?rss=all	計算とlf文の混合はどうやって書けばよろしいでしょうか華氏温度をCFで摂氏温度に変換し、更に計算結果に応じてコメントを出したいです。	2021-11-10 23:27:36
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	ローカル開発環境 (docker) の DB に socket を用いて接続しようとすると Address not available になります。	https://teratail.com/questions/368724?rss=all	ローカル開発環境dockerのDBにsocketを用いて接続しようとするとAddressnotavailableになります。	2021-11-10 23:21:48
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	タスクスケジューラが途中から狂う話	https://teratail.com/questions/368723?rss=all	タスクスケジューラが途中から狂う話タスクスケジューラの調子が悪いです、、、泣アルバイト先のサイト私は以前働いていたアルバイト先でデータサイトのようなものを作っています。	2021-11-10 23:19:01
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	スマホアプリのSNSログイン認証画面のデザイン	https://teratail.com/questions/368722?rss=all	スマホアプリのSNSログイン認証画面のデザイン背景としては下記の画像を使用して説明いたします。	2021-11-10 23:04:10
Linux	Ubuntuタグが付けられた新着投稿 - Qiita	Linux(Ubuntu)のUnityHubで, アーカイブバージョンのUnityをインストールする方法	https://qiita.com/KateSawada/items/37c5928da894fcbdcc2b		2021-11-10 23:25:25
技術ブログ	Developers.IO	Step Functionsステートマシンで実行したLambda関数のペイロードをパースする	https://dev.classmethod.jp/articles/parse-the-payload-of-a-lambda-function-executed-on-a-step-functions-state-machine/	awscdk	2021-11-10 14:52:47
海外TECH	MakeUseOf	PS5 Jailbreak Moves a Step Closer After PlayStation Hackers Reveal New Exploits	https://www.makeuseof.com/ps5-jailbreak-playstation-hackers-new-exploits/	closer	2021-11-10 14:55:26
海外TECH	MakeUseOf	How to Get a Delayed Project Quickly Back on Track	https://www.makeuseof.com/how-to-get-delayed-project-back-on-track/	timeline	2021-11-10 14:30:11
海外TECH	MakeUseOf	Hooks: The Hero of React	https://www.makeuseof.com/react-hooks/	react	2021-11-10 14:15:12
海外TECH	MakeUseOf	The Best Must-Have Smart Gadgets for This Winter	https://www.makeuseof.com/best-smart-gadgets-for-winter/	gadgets	2021-11-10 14:10:11
海外TECH	DEV Community	How To Make a Simple Calendar using HTML, CSS, and Javascript	https://dev.to/keshavs759/how-to-make-a-simple-calendar-using-html-css-and-javascript-4d9b	How To Make a Simple Calendar using HTML CSS and JavascriptIn this article we will learn how to make a simple calendar in HTML CSS and Javascript Html calendar is one of the widely used widgets in any website or blog It is easy as well as tricky at the same time to make a calendar using HTML CSS and Javascript We will understand the logic behind the javascript calendar using code and a video attached with this article To make this calendar using HTML CSS and Javascript first we used static values and then styled it We add some javascript later to make it dynamic The major role is played by the javascript date object Date and its function like getDay getFullYear getMonth etc The code for this project is self explanatory Comments are used to explain the code as per requirements We recommend you to watch the video along with the code to understand it betterThe video to make javascript calendar is Following is the code to make a simple calendar using HTML CSS and javascript Download Link HereFor similar widgets and websites components visit here Also Read How To make Responsive About Us page in HTML and CSS How to make a Responsive page not found in HTML and CSS How to make a basic login form and registration form using HTML and CSS Best Contact Us Page HTML TemplateFree Best Login Page Templates Written in HTML CSS and JS	2021-11-10 14:34:48
海外TECH	DEV Community	How Designers Can Prevent User Errors	https://dev.to/jrdnbwmn/how-designers-can-prevent-user-errors-5dpb	How Designers Can Prevent User ErrorsThe term user error implies that it s the user s fault when they do something wrong But in the vast majority of cases the fault actually rests with the designer for having created an interface that is confusing or makes it too easy for the user to make a mistake The solution to user errors is not to blame the user or try to train the mistakes out of them The solution is to redesign the product in such a way that it prevents errors from occurring in the first place There are lots of practical ways to do this and we re going to cover some of the most effective ones in this article Preventing errorsFirst let s talk through some preemptive ways you can help users avoid errors Install guardrailsProvide helpful constraints so that users can t make a wrong choice It s not always a good idea to limit options for a user but when there are clear rules for what works and what doesn t it s good to have guardrails in place to prevent mistakes Examples Phone number or credit card fields that don t allow alphabetic characters Airline sites that don t allow you to pick a return date that falls before your departure date Offer suggestionsLike constraints suggestions can guide the user toward the correct use of your product They can help avoid accidental errors find what they want and remember what options are available Examples Google search results offering suggestions for spelling errors Uber showing recent locations as possible destinations Autocomplete with contextual suggestions while the user types Choose smart defaultsGood defaults are helpful because they teach users what a reasonable value would be for the given input Pre populating fields with the most common value or a personalized one provides context and helps them see when they re on the wrong track Examples Using geolocation to determine what the likely departure location is on a flights app Presets like Tomorrow or Next Week in a reminders app Follow conventionsJakob s Law says “users spend most of their time on other websites Your users have been trained by thousands of other sites and apps to expect things to work in a certain way Not following these recognizable patterns often leads to errors Examples Placing navigation menus in standardized places Adapting content to typical scanning patterns Make actions clearYour design should communicate how it can be used That means that any affordancesーways in which you can interact with the interface like pushing a buttonーshould have indications of how they can be used If that isn t clear users may make mistakes trying to interact with it or skip it entirely Examples Explanatory labels on form fields Links and buttons that look distinct and clickable Preview resultsUsers might sometimes be unaware of the full impact of actions they re making Letting them review what their changes will look like helps them see into the future and solve their own problems before they happen This also allows them to play around and experiment without actually breaking anything Examples Previewing an email before sending it out or a blog post before publishing or a page before printing iOS showing you a preview of zoom settings before you submit the changes Give real time warningsGiving subtle contextual warnings while a user is actively making an error can help them to quickly and accurately correct it Install these warnings in areas where you know users are likely to make mistakes Examples Red highlights and negative numbers on Twitter when you ve surpassed the character limit MailChimp showing you whether or not you ve met each password requirement with a checkmark as you re typing a new password Confirm high stakes actionsA confirmation dialogue is a straightforward way to give the user a chance to pause and double check their action Keep in mind though that these confirmations disrupt a user s workflow if they get asked Do you really want to do that after every decision the user will get annoyed and worse will eventually ignore these dialogues altogether So only use confirmations on dangerous or destructive actions like deleting important information or assets Examples Facebook double checking with the user before permanently deleting a conversation from Messenger Gmail asking you if you want to include an attachment when your message mentions it What to do when a mistake happensNo matter how much you try to prevent it users will still make mistakes Our job as the designer is to provide a safety net to make errors less costly and to try to prevent the user from making the same mistake again in the future Support undoBeing able to undo recent actions is helpful and satisfying for users This is a direct counter to errors and makes the user more confident since they know a mistake can easily be fixed Note that features like a trash can also work like an undo because they allow you to revert changes by retrieving deleted items Examples Email clients with the ability to undo sending an email Multi level undo actions in document apps Provide error feedbackClearly communicating the error is essential if you want to educate the user about what happened what they can do about it and how to avoid it in the future A good error message will also the mistake seem less like a failure on the user s part and more like a cue for adjustment Be friendly positive engaging and helpful Examples Understandable inline form validation A useful page Design practices to implementFollowing these practices helps you figure out where users are likely to make mistakes and plan ahead Do user testingUser tests are the most reliable way to reveal obstacles problems and disconnects between mental models Set a user on a task and it ll become immediately obvious when they struggle fail or get frustrated Then you can either plan error prevention measures or better yet fix the design itself to help them avoid these mistakes Utilize metricsMetrics can be a cost effective way of figuring out where your users are running into issues Where are your users bouncing Where are they spending unusual amounts of time At what point are they leaving a workflow Record the answers and utilize all the tactics above to prevent errors Tying it offYou may have noticed that most of these things also lift the general level of UX across the product For example offering suggestions helps the user get to results faster previewing results allows for more user experimentation and performing user tests reveals more than just error prone areas Try applying these principles in your next UX project and see if it makes a noticeable difference Originally published on uxtools co UX Tools uxtoolsco How designers can prevent user errors PM Nov	2021-11-10 14:23:12
海外TECH	DEV Community	What is Data Lineage and How Can It Ensure Data Quality?	https://dev.to/mbogan/what-is-data-lineage-and-how-can-it-ensure-data-quality-4bk0	What is Data Lineage and How Can It Ensure Data Quality IntroductionAre you spending too much time tracking down bugs for your C level dashboards Are different teams struggling to align on what data is needed throughout the organization Or are you struggling with getting a handle on what the impact of a potential migration could be Data lineage could be the answer you need for data quality issues By improving data traceability and visibility a data lineage system can improve data quality across your whole data stack and simplify the task of communicating about the data that your organization depends on Hold on thoughーwhat exactly is data lineage What is Data Lineage Data lineage is a representation of the flow of data through different systems and transformations In a modern data stack data is not stored solely in application databases this data flows from one application to another and from application databases to data warehouses where it gets transformed and eventually consumed by any number of reporting tools and other downstream applications This flow of data allows each system to access data in a format that makes sense for it The source applications can optimize towards improving the performance of read write transactions At the same time reporting clients can access denormalized data which is convenient for querying Unfortunately this convenience comes at the cost of traceability and visibility Once the data leaves the source database and undergoes any number of transformations an additional layer has been added which can obscure the underlying data Reporting teams often struggle to understand where their data is coming from or determining the right data to use for a given report When they ask the application team the team might tell them that the data doesn t exist asーafter going through the transformation processーthe terms used to refer to a piece of data have changed Additionally solving any bugs or problems takes longer and requires the involvement of three teams the reporting team the data warehouse team and the application team Typically the burden of solving the issue falls onto the data team who then need to dig through version control to try and understand why the problem arose in the first place This slows down the development of new reports as well Data lineage solves these issues Let s discuss how Why use Data Lineage By providing a clear representation of the flow of data a data lineage system essentially allows you to have your cake and eat it too You can have both the separation of roles and the performance of a data warehouse while still having clear data understanding and traceability across all your systems and teams Clear data understanding and traceability allow you to trace important data across the system For example this can allow you to verify that no personally identifiable information PII is leaving the application systems and being consumed where it should not be It also allows you to see what data is frequently consumed downstream giving visibility into the impact of any potential changes or migrations Similarly you can identify any unused information allowing simple cleanup of unused tables or columns By increasing data understanding data lineage systems reduce incident response times and improve team communication Instead of confused discussions about where a piece of data in a report comes from the data lineage system makes it clear to all parties where the data comes from and how it is consumed This speeds up both resolution of any errors and new development Now that we know why data lineage is critical for the modern data stack let s look at the various types of data lineage systems Types of Data LineageThere are two main categories of data lineage systems active and passive An active data lineage system is “active because you must create it yourself This is done by programming the relevant source and transformation information into the system or tagging your data with the appropriate metadata One example of an active system is Apache Atlas A properly configured active data lineage system can provide traceability for your data to a very fine degree of detail However in order to gain those benefits constant updating and maintenance are required This adds complexity to your overall data infrastructure and can be time consuming In contrast a passive data lineage system attempts to understand your data on its own Some passive systems look at the data coming from the data warehouse Through pattern recognition a passive system attempts to recognize where that data is coming from and how it is being transformed While this can work well for simpler data sets and transformations it is inexact and can generate inaccurate results A parsing based system is another kind of passive data lineage system which generates lineage data by reverse engineering your data warehouse Rather than entering in the lineage data manually active systems or guessing based on data patterns pattern recognition a parsing based data lineage system can see exactly where the data came from and how it is being consumed Datafold is an example of this type of system Datafold analyzes all the DQL code in your data warehouse and generates column level lineage graphs This is significantly more detailed than table level lineage and allows you to see exactly which column a given piece of data is sourced from and where it is consumed This level of detail leads to improved outage response time allows for faster troubleshooting and decreases the frequency of breaking changes making it to production With numerous data warehouse integrations Datafold is plug and play for many and the generated lineage data is also accessible through the Datafold API As long as it has support for your data warehouse and related systems a parsing based data lineage system is the easy choice from an implementation and maintenance standpoint This is all great but what difference does data lineage make to my day to day Let s look at that How can Data Lineage Ensure Day to day Data Quality The improved visibility and traceability from a data lineage system has at least three clear effects on your operational day to day First it improves your team response time Investigating the cause of an error in a report no longer requires hours and the coordination of several separate teams With full visibility into the flow of data across your entire data stack errors can be investigated and resolved in record time Second it allows for the creation and maintenance of a common data vocabulary When the report team talks about views it is clear to the application team what that means and where that data comes from Similarly the application team can now see exactly what data is being aggregated for that dashboard which informs all the company decisions and outlook Over time discrepancies in terminology can be mitigated or removed allowing for smoother communication across the organization Finally the data lineage system allows teams to easily and effectively anticipate the effects of any potential changes or migrations Data schema changes and migrations can be planned out with certainty Full traceability makes it easy to understand the downstream impact of any changes and to notify the appropriate parties Wrap upIn this article we covered the basics of what data lineage is why you might want to use one the different types of data lineage and how data lineage can improve your data quality each day The addition of a data lineage system to your data stack can increase transparency and prevent headaches for your entire organization	2021-11-10 14:15:02
海外TECH	DEV Community	React context, performance?	https://dev.to/romaintrotard/react-context-performance-5832	React context performance Today we are going to talk about React context Its role is sometimes mistaken badly said as a mini redux Firstly we are going to see what it is then talk about performance and workarounds we have What is it I can t have a better definition than in the documentation Context provides a way to pass data through the component tree without having to pass props down manually at every level Conceptually you will put data in a React context and provides it to a React sub tree component thanks to a Provider Then in all components in this sub tree you are able to get the data thanks to a Consumer At every changes of the data in the context each consumers will be notified So there is no notion of state management here so don t be confused React context is not a mini redux But you can simulate it if you combine it with state or reducer However you have to be aware that redux supplies some features like time travellingmiddlewaresperformance optimizations How to use React context Creation of a contextThe creation is made thanks to the createContext method pulls from React This method takes as only parameter the default value that is optional const MyContext React createContext ProviderThe Provider is accessible through the created context const MyProvider MyContext Provider The Provider obtained is a Component has the following prop a value the value you want to provide to children componentschildren the children to which you want to provide the value lt MyProvider value valueToProvide gt children lt MyProvider gt Note Make a Provider component that takes children instead of putting directly components in the Provider like this function App const data setData useState null return lt MyContext Provider value data setData gt lt Panel gt lt Title gt lt Content gt lt Panel gt lt MyContext Provider gt Doing like this each time the setData is called it will render all components Title Content and Panel even if they do not use the data So instead do function MyProvider children const data setData useState null return lt MyContext Provider value data setData gt children lt MyContext Provider gt function App return lt MyProvider gt lt Panel gt lt Title gt lt Content gt lt Panel gt lt MyProvider gt ConsumerOnce we provide some data we probably want to get it somewhere in a child There is ways to get it with useContext hookwith the Consumer component provided by the context we created useContextIt s the hook to consume value from the context You just have to pass the context to the hook const myValue useContext MyContext Note You may want to create a custom hook useMyContext not to export the context directly It will allow you to make some check to ensure that the Provider has well been added const useMyContext gt const value useContext MyContext if value throw new Error You have to add the Provider to make it work return value Warning The check will not work if you put a default value in the context Consumer componentAs said previously the created context exports a Consumer component too like Provider you can then get the value by passing a function as children lt MyContext Consumer gt value gt Render stuff lt MyContext Consumer gt Recommendation and property Put context the closest to where it s usedAn advice is to put Providers the closest to where it s being used I mean do not put all your Providers at the top of your app It will help you to dive in the codebase with separation of concern and should help React to be slightly faster because would not have to cross all the tree components Note You will need to put some Provider at the top of your application For example InProvider SettingsProvider UserProvider Doing this you will may encounter some performance issues when parent re render if you pass an object as value most of the time it will be the case For example if you have const MyContext React createContext function MyProvider children const data setData useState null const onClick e gt Whatever process return lt MyContext Provider value data onClick gt children lt MyContext Provider gt function ComponentUsingContext const onClick useContext MyContext return lt button onClick onClick gt Click me lt button gt const MemoizedComponent React memo ComponentUsingContext function App const counter setCount useState return lt div gt lt button onClick gt setCounter prev gt prev gt Increment counter counter lt button gt lt MyProvider gt lt MemoizedComponent gt lt MyProvider gt lt div gt In this case when we increment the counter MemoizedComponent will re render even it s memoized because the value in the context changes In this case the solution is to memoized the value const value useMemo gt const onClick e gt Whatever process return data onClick data And tada MemoizedComponent do not render anymore when incrementing the counter Warning Memoizing the value is only useful if the components using the context are memoized Otherwise it will just do nothing and continue re rendering because parent re renders in the previous case the parent is App Nested providersIt s possible to do nested Provider for same context It s for example used in the react router implementation see my article In this case Consumers will get the value of the closest Provider to them const MyContext React createContext export default function App return lt MyContext Provider value parent gt lt ParentSubscriber gt lt MyContext Provider value nested gt lt NestedSubscriber gt lt MyContext Provider gt lt MyContext Provider gt function ParentSubscriber const value useContext MyContext return lt p gt The value in ParentSubscriber is value lt p gt function NestedSubscriber const value useContext MyContext return lt p gt The value in NestedSubscriber is value lt p gt In the previous example ParentSubscriber will get the value parent and in the other side NestedSubscriber will get nested PerformanceTo talk about performance we are going to do a little music app with few features be able to see what s our friends are listeningshow musicsshow the current musicImportant Do not judge the use of the React context features I know that for such features we would probably not use React context in real world Friends and musics featuresSpecifications friends feature consists to fetch every sec a fake API that will return an array of object of this type type Friend username string currentMusic string musics feature will fetch only once the available music and will return type Music uuid string A unique id artist string songName string year number Okay Let s implement this Innocently I want to put all this data in a same context and provide it to my application Let s implement the Context and Provider import React useContext useEffect useState from react const AppContext React createContext Simulate a call to a musics API with ms lag function fetchMusics return new Promise resolve gt setTimeout gt resolve uuid dbdc ad b aaab artist Justin Timberlake songName Cry me a river year Simulate a call to a friends API with ms lag function fetchFriends return new Promise resolve gt setTimeout gt resolve username Rainbow currentMusic Justin Timberlake Cry me a river export const useAppContext gt useContext AppContext export default function AppProvider children const friends setFriends useState const musics setMusics useState useEffect gt fetchMusics then setMusics useEffect gt Let s poll friends every sec const intervalId setInterval gt fetchFriends then setFriends return gt clearInterval intervalId return lt AppContext Provider value friends musics gt children lt AppContext Provider gt Now let s see the implementations of the Friends and Musics component Nothing complicated function Friends const friends useAppContext console log Render Friends return lt div gt lt h gt Friends lt h gt lt ul gt friends map username currentMusic gt lt li key username gt username listening currentMusic lt li gt lt ul gt lt div gt And function Musics const musics useAppContext console log Render Musics return lt div gt lt h gt My musics lt h gt lt ul gt musics map uuid artist songName year gt lt li key uuid gt artist songName year lt li gt lt ul gt lt div gt Now I will ask you a question Do you know what will be rendered print in the console Yep both Friends and Musics will rendered every around sec Why Do you remember that I told you each consumers will be trigger if the value provided changes even if they use a part of this value that does not change It s the case of Musics that only pulls musics that does not change from the context You can see it in the following codesandbox It s why I advise to separate data by business domain in different contexts In our example I will make two separate contexts FriendsContext and MusicContext You can see the implementation here Current listening musicNow we would like to be able to select a music from the list and listen it I m going to do a new context to store the currentMusic import React useContext useState from react const CurrentMusicContext React createContext export const useCurrentMusicContext gt useContext CurrentMusicContext export default function CurrentMusicProvider children const currentMusic setCurrentMusic useState undefined return lt CurrentMusicContext Provider value currentMusic setCurrentMusic gt children lt CurrentMusicContext Provider gt I add a button in the Musics component to listen the associated music function MyMusics const musics useMusicContext const setCurrentMusic useCurrentMusicContext console log Render MyMusics return lt div gt lt h gt My musics lt h gt lt ul gt musics map music gt lt li key music uuid gt getFormattedSong music lt button onClick gt setCurrentMusic music gt Listen lt button gt lt li gt lt ul gt lt div gt And the CurrentMusic component is simply function CurrentMusic const currentMusic useMusicContext console log Render CurrentMusic return lt div gt lt h gt Currently listening lt h gt currentMusic lt strong gt getFormattedSong currentMusic lt strong gt You re not listening a music lt div gt Ok now what is happening when you chose to listen a new music Currently both MyMusics and CurrentMusic will render Because when the currentMusic changes a new object is passed to the provider Separate dynamic and static dataOne strategy is to separate dynamic and static data in two different contexts CurrentMusicDynamicContext and CurrentMusicStaticContext import React useContext useState from react const CurrentMusicStaticContext React createContext const CurrentMusicDynamicContext React createContext export const useCurrentMusicStaticContext gt useContext CurrentMusicStaticContext export const useCurrentMusicDynamicContext gt useContext CurrentMusicDynamicContext export default function CurrentMusicProvider children const currentMusic setCurrentMusic useState undefined return lt CurrentMusicDynamicContext Provider value currentMusic gt lt CurrentMusicStaticContext Provider value setCurrentMusic gt children lt CurrentMusicStaticContext Provider gt lt CurrentMusicDynamicContext Provider gt And here we go Just to use the right hook to get value from the context Note As you can see it really complicates the code that s why do not try to fix performance issue that does not exist use context selectorThe second solution is to use the library made by dai shi named use context selector It will wrap the native context API of React to give you access to multiple hooks that will re render your component only if the selected value from the store changed The principle is simple you create your context thanks to the createContext function given by the lib Then you select data from it with the useContextSelector The API is useContextSelector CreatedContext valueSelectorFunction For example if I want to get the currentMusic const currentMusic useContextSelector CurrentMusicContext v gt v currentMusic Not to expose the context I made a hook export const useCurrentMusicContext selector gt useContextSelector CurrentMusicContext selector And that s all You can find the code bellow ConclusionWe have seen how to use React context and performance issues that you can encounter But like always do not do premature optimization Just try to worry about it when there are real problems As you have seen optimization can make your code less readable and more verbose Just try to separate different business logics in different context and to put your provider as close as possible to where it s needed to make things clearer Do not put everything at the top of your app If you have real performance problems because of contexts you can separate dynamic and static data in different contextsuseMemo the value if it s changing because of parent re rendering But you will have to put some memo on components that uses the context or parent otherwise it will do nothing use the use context selector lib to solve context s shortcomings Maybe one day natively in react as you can see in this opened PR one other strategy that we don t talk about it in this article is not to use React context but atom state management library like jotai recoil Do not hesitate to comment and if you want to see more you can follow me on Twitter or go to my Website	2021-11-10 14:04:15
Apple	AppleInsider - Frontpage News	Best deals Nov. 10: Apple Watch Sale, $160 off JBL headphones, and more!	https://appleinsider.com/articles/21/11/10/best-deals-nov-10-apple-watch-sale-160-off-jbl-headphones-and-more?utm_medium=rss	Best deals Nov Apple Watch Sale off JBL headphones and more Tuesday s best deals include off a Star Trek Playmobil set discounted JLab microphones and off an TB WD hard drive Best deals November There are a lot of sales each day but only a handful are worth pursuing So rather than sifting through miles of advertisements we ve hand picked a bunch just for the AppleInsider audience Read more	2021-11-10 14:51:50
海外TECH	Engadget	Smart home gadgets and kitchen tech that make great gifts	https://www.engadget.com/holiday-gifts-smart-home-kitchen-tech-gifts-150001873.html?src=rss	Smart home gadgets and kitchen tech that make great giftsKeeping your home clean organized and secure can be a chore and your loved ones likely feel the same way Fortunately there are gadgets that can help make it a little easier We review smart speakers robotic vacuums and Instant Pots all year long and for the holiday season we ve compiled a list of our recent favorites in the home tech space that will make excellent gifts And your giftee doesn t have to be tech savvy to use all of them either ーplenty of our recommendations amount to baby steps into the smart home world for those who would rather start off slow Instant Pot Pro img alt Instant Pot Pro for the Engadget Holiday Gift Guide src Will Lipman Photography for Engadget Instant PotWe almost always recommend the multi purpose Instant Pot in our holiday gift guides and this year is no exception But instead of giving your loved one the regular model why not level up Designed for avid cook the Instant Pot Pro brings several key upgrades over previous models The inner pot has an extra thick bottom that lets you heat it on the stove plus handles that make it easier to lift It has customizable programs for different foods and there are five favorite buttons that you can assign to frequently cooked meals It also has steam release reminder alerts with and minute pre sets It s available in two different sizes but we d recommend the six quart version for most families Buy Instant Pot Pro at Amazon Anova Precision Cooker Nano img alt Anova Precision Cooker Nano for the Engadget Holiday Gift Guide src Will Lipman Photography for EngadgetSous vide cooking essentially means keeping foods in a temperature controlled water bath ensuring they re done to perfection This used to require expensive equipment but sous vide cookers have become inexpensive over the past few years One such device is the Anova Precision Cooker Nano which can be found for around and can be controlled through either an app or physical buttons It s one of the most affordable sous vide machines around yet it delivers precise temperature controls The app also comes with an assortment of helpful recipes to help get users started on their sous vide journey If you don t mind spending a bit more we also like Breville s Joule for its sleek minimalist design It doesn t have the physical controls that the Nano does but it makes up for that with its compact form factor that s a little easier to fit in a kitchen drawer Either option will ensure medium rare steak juicy chicken breasts or just a perfectly soft cooked egg Buy Precision Cooker Nano at Amazon Buy Breville Joule at Amazon Anova Precision Oven img alt Anova Precision Oven for the Engadget Holiday Gift Guide src AnovaIf your loved one is a great cook with counter space to spare consider getting them the Anova Precision Oven It s a luxury purchase for sure but it s well worth the price for serious home cooks This combination convection steam oven can cook food in both wet and dry heat letting you control temperature and humidity levels What this means is that your special someone can make juicy roast chicken with crispy skin as well as crusty artisan style bread all in one machine Plus it has WiFi and a companion app that lets cooks keep an eye on their food from anywhere Buy Precision Oven at Anova Google Nest Doorbell Battery img alt Nest Doorbell for the Engadget Holiday Gift Guide src NestVideo doorbells are useful for seeing who s at the front door from the comfort of your couch One of our favorites is the Nest Hello now called the Nest Doorbell Wired which is why we were pleased when Nest came out with a new battery operated version the Nest Doorbell Battery It s a great gift for both homeowners and renters as you don t need to hardwire it Battery life is anywhere from one to six months depending on how active it is it s shorter if you live on a busy street for example The Doorbell notifies them whenever there s a person animal or vehicle near the front door It can also let them know when a package has been placed which is great for pre empting theft In addition it offers three hours of event video history for free with the option to purchase more space through a Nest Aware subscription Buy Nest Doorbell Battery at Best Buy Google Nest Hub nd gen img alt Nest Hub nd gen for the Engadget Holiday Gift Guide src NestIf you do get a Nest Doorbell for someone you might want to consider gifting them a Nest Hub as well The two are designed to work together anytime someone rings the doorbell the camera view of who s at the front door will show up on the Nest Hub s screen Even without the doorbell however the smart display is a great device to have around the home ーespecially if your loved one already uses the Google Assistant It works as a digital photo frame and they can use it to watch YouTube and Netflix It can also make calls via Google Duo and offers recipe videos along with step by step cooking instructions If the user so chooses they can track their sleeping patterns when they place the device next to their bed Buy Nest Hub nd gen at Best Buy Amazon Echo Show img alt Amazon Echo Show for the Engadget Holiday Gift Guide src Will Lipman Photography for EngadgetFor those who prefer Alexa over the Google Assistant the Echo Show is a great alternative to the Nest Hub It also works as a digital photo frame and its inch display is a good size for streaming shows from Amazon Prime Netflix and Hulu while prepping dinner It can also be used to keep up with the news check the weather and control smart home devices Since Amazon has a partnership with Allrecipes and Food Network Kitchen users can find assorted recipes and instructional videos as well Buy Echo Show at Amazon Mila Air purifier img alt Mila Air purifier for the Engadget Holiday Gift Guide src Will Lipman Photography for EngadgetAir purifiers are great gifts for anyone who has allergies lives in a polluted area or just wants to breathe easier at home And if you want to give someone a smarter air purifier consider the Mila Air It ships with one of seven pre configured HEPA filters that can filter out particles and allergens like pollen and dust It also has a ton of customization options there s a “Housekeeping Service mode that goes full blast when no one s in the room a “Sleep Mode that turns the lights off and reduces the fan speeds at night plus a “White Noise mode that mimics soothing sounds like waterfalls The Mila also has a bevy of sensors that can tell you if there s carbon monoxide in the air or if the humidity is too high Buy Mila air purifier Blink indoor cameraBlinkBlink s indoor camera offers the gift of peace of mind in a compact and affordable package Your loved one will appreciate the fact that Blink is wireless and battery powered since they don t have to place it near an electrical outlet it can sit almost anywhere They also won t have to worry about recharging the camera since it can last up to two years on its two included AA batteries Aside from just letting them monitor their home it also features customizable motion alerts so they ll only get alerted when they want to Plus there s two way audio so they can hear and speak to the person or pet on the other end Buy Blink Indoor at Amazon iRobot Roomba img alt iRobot Roomba for the Engadget Holiday Gift Guide src Will Lipman Photography for EngadgetMaybe you have someone in your life who could use a little help cleaning up after themselves For that we recommend getting them one of our favorite robot vacuum cleaners the iRobot Roomba It can suck up dirt and debris from both hardwood and carpeted floors with an edge sweeping brush taking care of dusty corners The companion app lets them control it remotely or they can set up a cleaning schedule so the little robot can do its thing at a set time It even automatically docks and recharges itself if it s low on battery Buy Roomba at iRobot August WiFi smart lock img alt August Smart WiFi smart lock th gen for the Engadget Holiday Gift Guide src AugustSmart locks are a great way to add security and convenience to any home We recommend August s WiFi smart lock because it s easy to use and since it fits over an existing deadbolt it s great for both homeowners and renters It lets your loved ones unlock the door completely hands free which is great if they have their arms full of groceries They can set it so that it automatically locks once the door is closed or after a set period of time If someone s at the door but they re at the office or in the backyard they can easily let them in with a single finger tap Plus they can grant access for specific friends or family members which means they might never need to put the key under the doormat ever again Buy August WiFi smart lock at Amazon TP Link Kasa smart plug img alt TP Link Kasa Smart Plug Smart Plug Mini for the Engadget Holiday Gift Guide src Will Lipman Photography for EngadgetWith a smart plug any appliance can be part of a connected home for not a lot of money TP Link s Kasa smart plug is a particularly good one because it is both affordable and incredibly compact and if you re really short on space there s a mini version that s even smaller Together with its companion app they can schedule a timer to turn on and off anything from Christmas lights to a coffee maker It s also compatible with both Alexa and Google Assistant which lets them add voice control to any outlet Buy Kasa smart plug pack at Amazon Buy Kasa mini smart plug pack at Amazon Eero WiFi mesh router img alt Amazon eero wifi router for the Engadget Holiday Gift Guide src AmazonWith most of us having so many gadgets and smart home devices perhaps the best thing you can give your loved one is the gift of better WiFi to keep things running smoothly Amazon s Eero routers will deliver just that The latest models support WiFi the latest and fastest WiFi standard and will support plus devices simultaneously It also covers up to square feet with WiFi speeds up to Mbps so it s unlikely they ll ever have to deal with dead spots or buffering again The Eero also comes with a built in Zigbee smart home hub that lets them connect compatible devices without having to purchase a separate device Buy Eero router at Amazon Philips LED Smart Bulb starter kit img alt Philips Smart light starter kit for the Engadget Holiday Gift Guide src PhilipsAdd some color to your loved one s life with the Philips LED smart bulb starter kit which comes with four multi color bulbs plus a Hue Hub that connects them all together The bulbs can fill the room with millions of different colors so they can choose from warm moody lighting for a cozy atmosphere or rainbows for parties In the companion app they can create timers and routines so that their lights gradually turn on in the morning or off in the evening And it s scalable They can eventually have up to lights connected to one Hue Hub giving them the freedom to outfit their whole home with smart lights if they wish Buy Philips Hue starter kit at Amazon	2021-11-10 14:42:31
海外TECH	Engadget	'Forza Horizon 5' had the largest launch for any Xbox Game Studios title	https://www.engadget.com/forza-horizon-5-largest-xbox-game-studios-launch-142019997.html?src=rss	x Forza Horizon x had the largest launch for any Xbox Game Studios titleMicrosoft s game development teams are having a banner year The company s gaming head Phil Spencer has revealed that Forza Horizon had the best launch day of any Xbox Game Studios title There have been over million people playing the arcade racer across all platforms Xbox Windows and cloud to date and its peak concurrent players were three times those of its predecessor Horizon is enjoyable as you might have gathered from our hands on but it also helps that the game had one of Microsoft s widest releases yet The new Forza launched simultaneously on Xbox Series X S Xbox One the Microsoft Store on Windows and through Steam It s much easier to pick up the game this time around and it s a major showcase for both Microsoft s latest consoles as well as PCs with high end video cards All the same it s a significant moment for Microsoft after years of buying and fostering developers to make Xbox Game Studios a well known brand There s a real chance the company will eclipse itself too with Halo Infinite poised to launch in less than a month It s just a question of whether or not these standout launches will translate to better Xbox sales We ve invested for years in Xbox so more people can play With million players so far across PC cloud amp console Forza Horizon shows that promise coming to life Largest launch day for XGS game peak concurrent x FH high Thank you players amp congrats to WeArePlaygroundーPhil Spencer XboxP November	2021-11-10 14:20:19
海外TECH	Engadget	Omorpho wants to make resistance training easier with its weighted workout clothing	https://www.engadget.com/omorpho-micro-weight-exercise-clothes-140059294.html?src=rss	Omorpho wants to make resistance training easier with its weighted workout clothingOne of the problems with the traditional weight belts or vests is that they re often bulky and ill suited to you retaining your full range of motion It s a problem that Omorpho is looking to tackle with its new Gravity Sportswear which spreads the weight across the garment The rationale for this and the use of what it s calling MicroLoad Spheres which are dotted all over like Michael B Jordan s torso from Black Panther is to offer greater resistance during workouts but not at the expense of movement Omorpho may be a new company but it comes from some pretty experienced names since it was founded by year Nike veteran Stefan Olander He is joined by a group of former Nike employees which have worked to build the clothes and finesse this system of weighting clothes The process of developing the garments has reportedly taken more than three years and uses premium fabrics in the construction And there are a number of big name athletes pitching the clothes including Julio Jones and Annie Kunz The entire collection which includes long and short sleeve tops vests and leggings is available to buy from Omorpho s website today Prices start from for the biker short through to for the beefiest G Vests all of which have a set weight that they can add to your daily workout nbsp	2021-11-10 14:00:59
金融	RSS FILE - 日本証券業協会	株主コミュニティの統計情報・取扱状況	https://www.jsda.or.jp/shiryoshitsu/toukei/kabucommunity/index.html	株主コミュニティ	2021-11-10 15:30:00
金融	RSS FILE - 日本証券業協会	公社債発行額・償還額等	https://www.jsda.or.jp/shiryoshitsu/toukei/hakkou/index.html	発行	2021-11-10 15:00:00
金融	金融庁ホームページ	「顧客本位の業務運営に関する原則」等に基づく取組方針を公表した金融事業者リスト（令和３年９月末時点）及び投資信託の共通KPIに関する分析（令和３年３月末基準）について公表しました。	https://www.fsa.go.jp/news/r3/kokyakuhoni/202111/fd_2021.html	投資信託	2021-11-10 15:00:00
金融	ニュース - 保険市場TIMES	大樹生命、8年連続でHDI格付け最高ランク三つ星評価獲得	https://www.hokende.com/news/blog/entry/2021/11/11/000000	大樹生命、年連続でHDI格付け最高ランク三つ星評価獲得「問合せ窓口」部門にて大樹生命保険株式会社は月日、HDIJapanが主催する年度公開格付け調査において最高ランクである三つ星評価を獲得したことを発表した。	2021-11-11 00:00:00
ニュース	BBC News - Home	Caerphilly dog attack: Woman, 28, is arrested by police	https://www.bbc.co.uk/news/uk-wales-59237518?at_medium=RSS&at_campaign=KARANGA	attack	2021-11-10 14:17:21
ニュース	BBC News - Home	PSG midfielder Diallo arrested amid investigation into attack on team-mates	https://www.bbc.co.uk/sport/football/59236410?at_medium=RSS&at_campaign=KARANGA	PSG midfielder Diallo arrested amid investigation into attack on team matesParis St Germain women s midfielder Aminata Diallo is arrested as part of an investigation into an attack on team mates on November	2021-11-10 14:32:48
ニュース	BBC News - Home	Playing with Tiger & winning with his son as caddie - Gallacher reaches 600 events on tour	https://www.bbc.co.uk/sport/golf/59158180?at_medium=RSS&at_campaign=KARANGA	Playing with Tiger amp winning with his son as caddie Gallacher reaches events on tourStephen Gallacher has played in a Ryder Cup and lifted his first title at St Andrews but what is his career highlight as he prepares for a th European Tour start	2021-11-10 14:02:49
ニュース	BBC News - Home	Czech billionaire Kretinsky buys 27% West Ham stake	https://www.bbc.co.uk/sport/football/59237403?at_medium=RSS&at_campaign=KARANGA	billionaire	2021-11-10 14:18:08
ビジネス	ダイヤモンド・オンライン - 新着記事	高島(8007)、大幅な「増配」を発表し、配当利回りが 5.4％にアップ！ 配当額は1年で2倍に急増、2022年 3月期は前期比で60円増となる｢1株あたり120円｣に！ - 配当【増配・減配】最新ニュース！	https://diamond.jp/articles/-/287283	高島、大幅な「増配」を発表し、配当利回りがにアップ配当額は年で倍に急増、年月期は前期比で円増となる「株あたり円」に配当【増配・減配】最新ニュース高島が、年月期の配当予想の修正増配を発表し、配当利回りがに高島は、年月期の年間配当を前回予想比で「円」の増配、前期比でも「円」の増配となる「株あたり円」に修正すると発表した。	2021-11-10 23:05:00
北海道	北海道新聞	ＮＹ円、１１３円前半	https://www.hokkaido-np.co.jp/article/610285/	外国為替市場	2021-11-10 23:14:00