投稿時間:2021-04-17 03:21:37 RSSフィード2021-04-17 03:00 分まとめ(28件)

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AWS	AWS Architecture Blog	Field Notes: Building Automated Pipeline Corrosion Monitoring with AWS IoT Core	https://aws.amazon.com/blogs/architecture/field-notes-building-automated-pipeline-corrosion-monitoring-with-aws-iot-core/	Field Notes Building Automated Pipeline Corrosion Monitoring with AWS IoT CoreThis post was authored by Venkatesh Muthusami Principle Consultant Infosys Technologies Sudharsan Chinnappan Analyst System Development Infosys Technologies Kenneth Francis Dias Technology Architect Infosys Technologies and Ashutosh Pateriya Partner Solutions Architect AWS Pipelines are crucial to the oil and gas industry across upstream midstream and downstream sectors For industries like oil and gas the pipeline …	2021-04-16 17:26:55
python	Pythonタグが付けられた新着投稿 - Qiita	Apple Silicon(M1チップ)におけるpyenv+pipenvでのPython環境構築	https://qiita.com/kita_ds12/items/d947c56d285af7c64e49	pyenvlocalpyenvversiongtgtsetbyUsersユーザ名testpythonversionと表示されればOKpipenvでの仮想環境の作成の仮想環境を作成・実行pipenvpythonpipenvshellこれで仮想環境に入れたので必要なライブラリをインストールしましょう。	2021-04-17 02:22:39
js	JavaScriptタグが付けられた新着投稿 - Qiita	QR忘れ物アプリ (1) 環境構築 [Vue,Vuetify,Firebase]	https://qiita.com/rayan/items/5d04ee2ca7860c220dec	firebase は FirebaseCLI の コマンド です 。	2021-04-17 02:06:31
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	webスクレイピングページ移動	https://teratail.com/questions/333641?rss=all	webスクレイピングページ移動前提・実現したいことwebスクレイピングでページ移動をしたいwebのurlnbsppythonnbspwebスクレイピングに関して初心者なので汚かったらすいません発生している問題・エラーメッセージwebnbspページにnextボタンページ移動があるのですがxpathでクリックするとInternalnbspServernbspErrornbspというエラーがでてしまいます。	2021-04-17 02:44:07
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	C　DXライブラリ　画像を分割して読み込めない	https://teratail.com/questions/333640?rss=all	CDXライブラリ画像を分割して読み込めない実現したいこと画像を分割し、指定したものを表示したいです。	2021-04-17 02:20:56
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	【Slack】Webhookを用いたチャンネルへのメッセージ送信	https://teratail.com/questions/333639?rss=all	【Slack】Webhookを用いたチャンネルへのメッセージ送信やりたいことslackの特定のチャンネルへメッセージを投げようとしております。	2021-04-17 02:14:05
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	JavaScriptのclickイベントを使った簡単な問題	https://teratail.com/questions/333638?rss=all	JavaScriptのclickイベントを使った簡単な問題前提・実現したいことJavaScriptのclickイベントを使った問題を、if文による条件分岐も使用して作成したいです。	2021-04-17 02:11:00
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	rails　scssが反映されません	https://teratail.com/questions/333637?rss=all	railsscssが反映されませんrailsでwebアプリを作成中です。	2021-04-17 02:08:05
海外TECH	Ars Technica	Valve Anti-Cheat’s “permanent” bans now have one major exception	https://arstechnica.com/?p=1757463	esports	2021-04-16 17:18:23
海外TECH	Ars Technica	Google loses “Location History” court battle in Australia	https://arstechnica.com/?p=1757430	australia	2021-04-16 17:02:47
海外TECH	DEV Community	Animations without JS...or CSS...or IMAGES??!? 😲 Pure HTML animation!	https://dev.to/inhuofficial/animations-without-js-or-css-or-images-pure-html-animation-45di	Animations without JS or CSS or IMAGES Pure HTML animation I recently created a countdown timer that used no JS CSS or HTML But now I have gone even more insane I present to you an animation that doesn t use any images An animation that doesn t use any CSS An animation that doesn t use any JavaScript It is all done with pure HTML Click here to experience it in all of it s glory sorry I can t make it work on dev to Spoilers lie below so make sure you click the link and see it in action before scrolling down Spoilers in Spoilers Yes I did just Rick Roll you with ASCII text I title the piece Rick ASCIIly groan So what is going on Super simple there are pages each with a different frame of our ASCII video Each frame is then set to automatically load the next page using lt meta http equiv refresh content URL next image URL gt The last page then points to the first page to create an infinite loop By setting the delay to and with a fast enough connection or when all the images are cached locally it actually performs reasonably well it is just a shame I can t play audio as well Why Does it have any practical uses no Did it get me locked out of my server as it triggered Mod Sec with too many requests Absolutely Is it a bit of fun on a Friday YesSo happy weekend people you got rick rolled with ASCII text so I win the internet for today Leave a comment if you hate me for this	2021-04-16 17:31:02
海外TECH	DEV Community	Useful Resources To Learn Web Development & To Create Your Website	https://dev.to/apoorvtyagi/useful-resources-to-learn-web-development-to-create-your-website-19nm	Useful Resources To Learn Web Development amp To Create Your Website IntroductionLearning web development is like learning to drive a car No matter how much you do not enjoy it learning these skills sometimes can help you a lot and can even act as a great skill to put on your resume It s been over years since I last touched anything related to HTML CSS or any Javascript front end framework but recently I happen to come across all of them at once I needed to create some landing pages custom logos and mockups So I decided to go through all these technologies once again and during that process I found several interesting resources that helped me and will be useful for you as well I am sure if you re someone who is just starting out or even if you are at intermediate level these resources can come pretty handy Learning Javascript Because I previously have experience working on Javascript therefore I didn t spend much time revising my old concepts Still during the process I found these two amazing github repositories to refresh your JS concepts Javascript Concepts leonardomso js concepts concepts every JavaScript developer should know This is an amazing repository for you to master your JavaScript concepts From basic topics like Call Stack Primitive types to Message Queue amp event loop to concepts like async await High Order Funtions and Clean Code conepts this repo contains everything you need It is even considered by GitHub as one of the top open source projects of Web security basics vasanthk web security basics Web security concepts This is for a quick review of basic web security concepts It covers following topics SSL TLS CORS Cross Origin Resource Sharing Cross site Scripting attack CSRF Cross Site Request Forgery Access and Refresh Tokens Learning CSS Honestly the reason why I don t enjoy web development is because I suck at CSS So the first thing I did this time was to look for online resources to start learning and practicing my CSS skills from scratch Here are the courses that turned out to be really helpful Learning HTML Although for my project I didn t go back to learn HTML but just for the sake of this blog post I found this FreeCodeCamp s video on youtube that I feel gives a very nice introduction to learn the basics of HTML ️It covers following topics Basic Tags Comments Style amp Color Formatting a Page Links Images Videos amp Youtube iFrames Lists Tables Divs amp Spans Input amp Forms Frames Meta Tags E Book HTML To React The Ultimate GuideI am a huge fan of books both eBooks and Paperbacks and I found out this amazing course of gumroad This ebook is a comprehensive guide that teaches you everything you need to know to be a web developer through a ton of easy to understand examples and proven roadmapsIt contains Straight to the point explanationsSimple code examples Interesting project ideas Checklists of secret resourcesA Bonus Interview prepYou can even check out a free sample from this bookand here s the link to the complete book if you want to buy it for yourself Create Professional Mockups If you want to create mockups of your application Shotsnapp will help you create beautiful device images for your app or website designs Checkout Screely com as an alternative for Shotsnapp Icons and Logos If you re looking to add icons and logos then here are some good websites that offer well optimized most popular icons and logo sets ConclusionThis blog post was a brief guide for Web Developers You can share it with your friends who want to start their careers as a Web Developers too There are plethora of both free and paid online web development courses and hopefully one of the above resource can help you to get started or to improve your skills In case I missed any awesome web development resource or tool Let me know in the comments below Thanks for reading Enjoyed what you read You can show some love by buying me a coffee	2021-04-16 17:16:45
海外TECH	DEV Community	5 Things Every React Developer Should Know About State	https://dev.to/reedbarger/5-things-every-react-developer-should-know-about-state-5910	Things Every React Developer Should Know About StateOne of the most important concepts for every React developer is state what it is how to properly use it and to avoid common pitfalls as your build your applications Let s cover five of the most essential parts of state that you need to know each of which build upon each other to aid your overall understanding of a somewhat complex topic To make these abstract concepts as clear as possible I ve included many practical examples that you can run in Code Sandbox or any React project you have set up Want to become a professional React developer in record time Check out the React Bootcamp State updates with useState are not mergedOne challenge many React developers face when moving from class based components to function components with React hooks is that state updates using objects are no longer automatically merged A great advantage of the useState hook is that we are able to call it as many times as we like to use as many state variables as we need In this example we have a basic form with an email and password input We are managing the email and password state as individual state variables import React from react export default function App const email setEmail React useState const password setPassword React useState return lt form gt lt input name email type email placeholder Email onChange e gt setEmail e target value gt lt input name password type password placeholder Password onChange e gt setPassword e target value gt lt button type submit gt Submit lt button gt lt form gt Let s change our example to manage our form state within a single object This allows us to call useState just once where email and password are not managed by individual state variables but as properties of this one state variable called state How do we appropriately update state with the setState function when it is an object If we were to use a generic event handler that is connected to the onChange prop of each of our form s inputs it would look something like this import React from react export default function App const state setState React useState email password function handleInputChange e setState e target name e target value return lt form gt lt input name email type email onChange handleInputChange gt lt input name password type password onChange handleInputChange gt lt button type submit gt Submit lt button gt lt form gt We now updating each input s value in state according to the name of the input our user is currently typing in This pattern is commonly used to update state in class based components but this does not work with the useState hook State updates with useState s setState function are not automatically merged What does that mean It means that whenever we set state as our user types in the previous state is not included in the new state If we were to log our newly updated state as we type into our form we see the following Since the previous state is not automatically merged into the new state object we must manually merge our state object with its previous properties using the object spread operator import React from react export default function App const state setState React useState email password function handleInputChange e setState spread in previous state with object spread operator state e target name e target value return lt form gt lt input name email type email onChange handleInputChange gt lt input name password type password onChange handleInputChange gt lt button type submit gt Submit lt button gt lt form gt For the useState hook we have the flexibility to manage multiple primitive values or use an object with multiple properties If you useState with an object however remember to spread in the previous state when performing any updates to make sure it is updated correctly State hooks trigger a re render useRef does notReact state has a very important relationship with rendering components Whenever we return JSX from a React component when that component is used it will be rendered and therefore be displayed in our application React takes care of this rendering process If our component uses any state we must understand that it needs to be rendered again re rendered in response to any state update Why do components need to be re rendered upon state updates Because if we did not re render upon updating state we would not be able to show new data This is very simply expressed whenever we are showing any state contained within a state variable within our JSX If it did not re render whenever we make changes to that variable the updates would not be shown This seems like a rather simple concept but you need to understand that whenever we update state it not only causes a re render in the component that directly manages the state it also causes a re render in all child components Why does this matter Because in some cases we may not want a child component to re render in response to a parent component re rendering What is one such example Let s say we have application where a user can type into an input whose value is managed through state This app also has another component that displays a list of data Whenever the user types into the input our state is updated and this causes a needless re render in that other child component The way that we can fix this is with the help of the React memo function which helps in preventing our component from being re rendered when a parent component re renders export default function App const skill setSkill React useState const skills setSkills React useState HTML CSS JavaScript function handleChangeInput event setSkill event target value function handleAddSkill setSkills skills concat skill return lt gt lt input onChange handleChangeInput gt lt button onClick handleAddSkill gt Add Skill lt button gt lt SkillList skills skills gt lt gt But the problem if you run this code yourself is that when we type into the input because the parent component of SkillList App re renders due to the state being updated on every keystroke the SkillList is rerendered constantly as indicated by the console log However once we wrap the SkillList component in React memo which is a higher order function meaning it accepts a function as an argument it no longer re renders unnecessarily when our parent component does const SkillList React memo skills gt console log rerendering return lt ul gt skills map skill i gt lt li key i gt skill lt li gt lt ul gt One other thing to note here is that there is technically a way to manage state without causing a re render We can do so with a hook that most people don t view as being a stateful React hook useRef useRef can be used to store any value on its current property In other words if we wanted to make a simple counter with useRef and update a count value that we stored on it even if we update its value it would not the correct count after the initial render because doing so does not trigger a re render import React from react export default function App const countRef React useRef function handleAddOne countRef current return lt gt lt h gt Count countRef current lt h gt clicking this will not change display count lt button onClick handleAddOne gt lt button gt lt gt State updates should be immutableA very important part of state in React is that it must be updated and managed in the correct way When it comes to managing state with the useState hook we must only use the dedicated setter function as provided as the second element in the array we get back from useState to update it If we don t do so and attempt to update it manually with the help of just plain JavaScript for example our application will not work like we expect This point is very closely related to the previous point that we made state when updated properly causes a re render of our component What do you think will happen if we attempt to update state in our own way instead of the React way Again React is what takes care of displaying and rendering our component properly when something changes If we don t use React then we can t expect our application to reflect any changes that we made them state In other words if we update state with plain JavaScript and not setState it will not trigger a re render and React will not display those invalid changes in state to our user This is a simple but crucial lesson to remember We must know how to update state using React and choose the appropriate state hook for our purposes we might choose useReducer useState or a third party state management library like Redux Regardless of our choice in state management we must update state in the appropriate manner and not attempt to update or mutate it directly The other reason for this aside from our React application not working properly is that it violates a core principle of React This is the concept of immutability State updates should always be immutable This means we shouldn t make our own changes or mutate the data stored in our state variables Doing so makes our state unpredictable and can cause unintended problems in our application that are hard to debug import React from react export default function App const count setCount React useState Don t assign state to new non state variables const newCount count Don t directly mutate state const countPlusOne count return lt gt lt h gt Count count lt h gt lt gt In addition to not mutating state variables directly make sure to never assign state variables to other non state variables State updates are asynchronous and scheduledA crucial lesson to know about state updates is that they are not performed immediately This can be seen if we take a look at the React documentation and see exactly what happens when we call the setState function We use it to update the state variable associated with it but we re also told It accepts a new state value and enqueues a re render of the component What does this word enqueues mean In other words it doesn t re render the component immediately It doesn t stop our code right at that line where we update state but it takes place at some point in the future This is for performance purposes and this gives us a better idea of what React is doing under the hood Based off of this information we need to change our mental model when we attempt to update state the setState function does not immediately update state it merely schedules a state update for some time in the future After which React takes care of figuring out when that state update takes place Therefore it s not so easy just to be able to look at our code and see exactly when the state update occurred or will occur This is important to compare to useRef which we mentioned earlier as being able to hold on to the data within its current property Any updates made with useRef are performed synchronously we can look at our code and see exactly when a given update was performed in useRef but not with useState Stale state can happen with closuresFinally an important problem that can occur with React state is the problem of stale state What is stale state Stale state is a problem that occurs whenever we re trying to update state often within a closure A closure is a type of function in JavaScript where we re using a variable from an outer scope This problem of stale state is based around the fact that closure might not capture the most up to date state variable value That s what we mean by stale we mean that it is old and not the current value that we want This problem of stale state is closely related to the topic that we discussed that the previous topic of state updates being asynchronous In many cases what is a problem about state updates being asynchronous is that we don t always get the correct previous value of our state especially if we re trying to update state based off of that previous value We can express the problem of a stale closure within a simple counter application that updates the count after a second using the setTimeout function Because setTimeout creates a closure we are accessing a stale value of our state variable count when we call setCount import React from react export default function App const count setCount React useState function delayAddOne setTimeout gt setCount count return lt gt lt h gt Count count lt h gt lt button onClick delayAddOne gt lt button gt lt gt The problem is apparent when we run our application despite clicking the button multiple times it is still only incremented by one every second We can fix this and fix this problem of our stale state within our closure by using a more reliable method of updating state The state updates are still going to be scheduled but it will make it possible to reliably get the previous value of state We do this with the help of providing an inner function to the setState function In the body of the function we can get the previous state within the parameters of this function and then return what we want the next state to be In our case it will be the previous count value incremented by one import React from react export default function App const count setCount React useState function delayAddOne setTimeout gt stale state problem goes away using inner function setCount prevCount gt prevCount return lt div gt lt h gt Count count lt h gt lt button onClick delayAddOne gt lt button gt lt div gt Another interesting thing to note if you take a look at the React documentation is that if nothing is returned from this function then no re render is going to take place whatsoever Once we provide this inner function to setState to reliably get the previous state and return the new state from our function our stale state problem due to our closure goes away Enjoy this post Join The React BootcampThe React Bootcamp takes everything you should know about learning React and bundles it into one comprehensive package including videos cheatsheets plus special bonuses Gain the insider information hundreds of developers have already used to master React find their dream jobs and take control of their future Click here to be notified when it opens	2021-04-16 17:03:36
海外TECH	Engadget	Facebook’s Oversight Board has delayed its decision on Trump’s suspension	https://www.engadget.com/facebook-oversight-board-donald-trump-decision-delayed-173841306.html	comments	2021-04-16 17:38:41
Cisco	Cisco Blog	History of Pluggable Optics Continued: Cisco Optics Podcast Episode 2 Notes	https://blogs.cisco.com/sp/history-of-pluggable-optics-continued-cisco-optics-podcast-episode-2-notes	History of Pluggable Optics Continued Cisco Optics Podcast Episode NotesJoin us for Episode of the Cisco Optics Podcast where we discuss the history of pluggable optics in a conversation with Ray Nering an engineering product manager in the Cisco Optics product management group	2021-04-16 17:18:43
海外TECH	CodeProject Latest Articles	An Introduction to Containerization	https://www.codeproject.com/Articles/5298350/An-Introduction-to-Containerization	An Introduction to ContainerizationThis article provides experienced developers with a comprehensive look at containerization where it came from how it works and a look at the typical tools you d use to build and deployed containerized cloud native apps	2021-04-16 17:30:00
海外科学	NYT > Science	Why the Vaccine Safety Numbers Are Still Fuzzy	https://www.nytimes.com/2021/04/16/upshot/vaccine-safety-analysis.html	johnson	2021-04-16 17:18:04
海外TECH	WIRED	A Pause on J&J, Preparation for Booster Shots, and More News	https://www.wired.com/story/pause-jandj-preparations-booster-shots-coronavirus-news	important	2021-04-16 17:22:43
海外ニュース	Japan Times latest articles	BOJ likely to discuss raising economic outlook, sources say	https://www.japantimes.co.jp/news/2021/04/16/business/economy-business/bank-of-japan-economic-outlook/	economy	2021-04-17 02:46:50
海外ニュース	Japan Times latest articles	Tokyo Olympics chief commits to games as infections surge, amid fresh calls to postpone or cancel	https://www.japantimes.co.jp/news/2021/04/16/national/medical-journal-tokyo-olympic-cancellation/	Tokyo Olympics chief commits to games as infections surge amid fresh calls to postpone or cancelJapan has exhibited poor performance in containing transmission along with limited testing capacity and a slow vaccination rollout health experts wrote in the British Medical	2021-04-17 02:43:29
海外ニュース	Japan Times latest articles	Caster Semenya open to 5,000-meter qualification bid for Tokyo Olympics	https://www.japantimes.co.jp/sports/2021/04/16/olympics/summer-olympics/olympics-track-and-field/semenya-open-to-5000/	Caster Semenya open to meter qualification bid for Tokyo OlympicsCaster Semenya retained her meter title at the South African Athletics Championships on Thursday and confirmed she would not be attempting to qualify for the	2021-04-17 03:54:46
海外ニュース	Japan Times latest articles	‘King’ Kohei Uchimura confident of walking narrow path to Tokyo Olympics	https://www.japantimes.co.jp/sports/2021/04/16/olympics/summer-olympics/olympics-gymnastics/uchimura-confident-to-olympics/	olympics	2021-04-17 03:26:04
海外ニュース	Japan Times latest articles	Shauna Coxsey heading to Tokyo Olympics with newfound need for speed	https://www.japantimes.co.jp/sports/2021/04/16/olympics/summer-olympics/shauna-coxseys-olympic-speed/	Shauna Coxsey heading to Tokyo Olympics with newfound need for speedCoxsey says the one year delay the Olympics has made her even more excited even if the games will be muted by strict COVID protocols	2021-04-17 02:46:22
海外ニュース	Japan Times latest articles	Malaysian company aims high with cultivation of Japanese muskmelons	https://www.japantimes.co.jp/life/2021/04/16/food/malaysian-melons/	fruit	2021-04-17 03:47:44
ニュース	BBC News - Home	Peaky Blinders actress Helen McCrory dies aged 52	https://www.bbc.co.uk/news/entertainment-arts-56770593	harry	2021-04-16 17:38:56
ニュース	BBC News - Home	Pregnant women should be offered Covid vaccine	https://www.bbc.co.uk/news/health-56778146	advisers	2021-04-16 17:47:31
ニュース	BBC News - Home	Hong Kong: Jimmy Lai sentenced to 14 months for pro-democracy protests	https://www.bbc.co.uk/news/world-asia-56770567	beijing	2021-04-16 17:01:42
ニュース	BBC News - Home	Billie Jean King Cup: Heather Watson & Katie Boulter give Great Britain lead over Mexico	https://www.bbc.co.uk/sport/tennis/56760606	Billie Jean King Cup Heather Watson amp Katie Boulter give Great Britain lead over MexicoHeather Watson and Katie Boulter put Great Britain ahead in their Billie Jean King Cup play off against Mexico	2021-04-16 17:02:41