vue.js 學習手冊 框架的選擇與導入
這篇文章是vue.js學習手冊的第一篇文章，也是我認為最難寫的一篇文章，就像vue.js提到的他是一個“漸進式”框架，在這篇文章也想要跟各位分享選擇框架的一些原則，讓大家可以“漸進式”的了解為什麼我們在網頁開發時需要選擇一個框架來幫助我們，在選擇框架之前我們要先弄清楚，框架究竟可以幫助我們在網頁開發上的哪些部分，如果這些部分跟你要開發的項目並不媒合，那奉勸你別把單純的事情搞複雜了，而且你可能會開始討厭學習框架，但若反之，你一定會愛上框架，甚至覺得他讓你事半功倍。
強大的前、後端串接功能
現代的網頁被要求除了有著摩登的前端UI之外，在網頁中的資料有常需要配合“大數據”下的資料進行呈現，說白話一點也就是網頁上面呈現的資料並不是寫死在頁面中的，而是透過後端資料庫取出來的，舉凡會員登入的名稱、購物網站中的商品資訊、新聞網站中的新聞就連你現在看到的這篇文章，也都是存放於資料庫中，網頁去對資料庫進行讀取後顯示在介面上的。
當然除了對資料庫進行讀取之外，網頁也會對資料庫進行儲存的動作，舉凡會員資料修改、商品訂單建立、網站偏好設定…等等，而框架在這方面有許多很好的方法，讓我們可以更周全快速的處理這方面的動作，節省許多開發的時間與減少Bug上的產生。
模組化開發架構
在一個大型網站中，可能有許多網頁中會出現相同風格的元素，例如：下拉式選單、按鈕、分頁導覽，是每一個頁面都會重複應用到的一些元件，傳統的網頁開發上就是在每一頁嵌入對應的HTML Code，這樣的做法非但不易維護，也會增加許多冗長且重複的程式碼。
模組化開發可以如上圖所示，將頁面中需重用的元素拉出來設計成一個Component，在不同頁面可以透過引入的方式置入該Component，而Component的維護可以統一在該Component中進行，可以減少大量維護上的時間。
透過 Virtual DOM 來提升頁面效能
現代的網頁前端框架為了提升頁面操作的效能都提供了Virtual DOM，在Vue.js 2.0中也引入Virtual DOM，比Vue.js 1.0的初始渲染速度提升了2~4倍，並大大降低了內存消耗，至於為何Virtual DOM能提昇網頁的效能，大家就必須了解我們透過Javascirpt更新實體DOM時會產生的效能問題開始了解。
實體DOM更新的效能測試
這邊製作一個簡單的範例對實體DOM和虛擬DOM的效能進行說明：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title></title>
</head>
<body>
<div class="wrapper">
<div class="container">
<div class="itemList">
<ul id="itemList__ul">
<li id="liID">Item 1</li>
</ul>
</div>
</div>
<button onClick="insertItems()">Go</button>
</div>
</body>
</html>
<script>
var itemData = "";
function insertItems() {
for (var i = 1; i <= 100000; i++) {
itemData = "Item " + i
document.getElementById("liID").innerHTML = itemData;
}
}
</script>
在HTML DOM的操作上，只要頁面元素有變更，就可能會觸發Reflow或Repaint這樣的動作，瀏覽器也會耗費相當多的資源在進行這些動作，以上述的例子來看，當我們按下頁面上的按鈕之後，就會透過迴圈去改變li的內容，這樣將會觸發多次的瀏覽器動作。
下圖是我們在Chrome中獲得的效能資訊：
若是我們將上述程式中的第26行移除，則效能會改變如下圖所示：
這樣可以很明確的了解效能殺手就是程式中的第26行，而這行程式的目的是去更新瀏覽器中的內容，若沒有這行沒辦法讓使用者看到最終的結果，因為我們必須透過這樣的方式更新DOM內容。
虛擬DOM的效能測試
同樣頁面的效果，我們在Vue裡面的作法如下：
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title></title>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
<ul>
<li v-for="item in items">{{ item.message }}</li>
</ul>
<button @click="insertItems">Go</button>
</div>
</body>
</html>
<script>
var vueData = {
items: [
{ message: 'Item 1' }
]
}
var app = new Vue({
el: '#app',
data: vueData,
methods: {
insertItems: function(){
for(var i = 1; i <= 100000; i ++){
vueData.items[0].message = "Item " + i;
}
}
}
})
</script>
同樣的結果在Vue會在Javascript和瀏覽器中加入一層Virturl DOM，待Virturl DOM更新完畢之後，在寫入瀏覽器中。
透過這樣的方法，使用這得到的一樣的效果，但大大提高了使用者端瀏覽器的效能，可以從下圖觀察的出來！
在Virtual DOM的架構中，會把程式的動作動作集中在Virtual DOM中運算，當確定整個頁面結構之後，再一次性地將結果繪製到頁面中，可以想像成原本的DOM操作就是在每一次在CPU運算之後，直接把結果寫到硬碟當中，而Virtual DOM就是在CPU與硬碟間加入了記憶體層，CPU運算後先將結果儲存在記憶體中，最後再將記憶體的資料一次性的寫入硬碟。
PS：記憶體的運算速度超過硬碟很多倍。
結論
綜合上述所說，網頁專案中採用前端框架，有著減少開發時間、易於維護、增加頁面效能…等優點，但若你的專案並不會大量與後端串接、製作上元件重複使用的機會不高、在頁面中也不太會對DOM進行Reflow與Repaint，可能是一個活動網頁、公司形象網頁…等，也許就沒有必要去選用一個前端框架，簡言之工具用在正確的地方，才能顯現出它的價值，當然目前符合使用框架的專案也一定非常多，也就是這樣的原因，才會造成前端框架的流行。
промокод Getcourse Pay [url=http://platezhnyj-modul-getkurs-promokod.ru/]промокод Getcourse Pay[/url] .
Для тех, кто ищет проститутки индивидуалки города на выезд, мы подготовили лучшие предложения. Все анкеты тщательно проверены, чтобы обеспечить надежность и безопасность. Страстные встречи, романтические моменты или яркий досуг — выбор за вами. Оцените разнообразие и легкость поиска.
Узнайте стоимость диплома высшего и среднего образования и процесс получения
Купить диплом старого образца, можно ли это сделать по быстрой схеме?
Rain man. Cancun mexico. Where is taylor swift from. Top hat. Trojan horse. Flashdance. Influenza b. Viral. Bean. Google docs. Tornado. Ed gein. Ac dc. Chicago il. Solitaire game. Antonio banderas. Gatsby. One direction members. Address. Harry potter and the order of the phoenix. Malinois. Joker. Sex and the city cast. Procedure. Australian shepherd. Patriots day. Venn diagram. Romeo and juliet movie. Date today. Look. Habanero. Uu. Jack white. Jim crow. Supine. Tony sirico. Clearwater florida. Debbie harry. Dysarthria. Harlequin. Yom kippur war. Pine tree. Ship. Roswell. Danica patrick. Sam smith. Augusta ga. Pound symbol. https://2025.uj74.ru/IXOXW.html
Miami vice. Matt gaetz. Mycoplasma. Home alone 2. Muzzle. Americans. Zach galifianakis. Mcculloch v maryland. Scarlett johansson. Affirmative action. Movies with timothee chalamet. Knicks roster. The outsider. Succeed. Valley. Better synonym. Argentina national football team. Leo dates. Google dcos. The mule. Chromium. Aster. 50 states. Consumer reports. What is matcha. Marilyn monroe. Judy garland. Chevy chase movies. Mike white. Six feet under. Aruba. Oman. Hybrid. Cons. Doha. Prior. Millennium. Tommy tuberville. Animation. What is a lobotomy. Lithuania. Drake age. Alexandrite. Joe manchin. Orc. Medvedev. What are capers. Natalie portman movies. Elysium. Corn snake. Zambia. World series. Red bottom heels. Robert downey jr.. Ernest hemingway. Bull. Penguins. Jk simmons movies and tv shows. Mississippi burning.
Услуги монтажа септиков по Воскресенскому району Работаем без выходных.https://drenaj-mos.ru/
Узнайте, как безопасно купить диплом о высшем образовании
ultrabet tr online: ultrabet giris – ultrabet yeni giris 1125
Как получить диплом техникума официально и без лишних проблем
промокод геткурс https://platezhnyj-modul-getkurs-promokod.ru .
Аттестат школы купить официально с упрощенным обучением в Москве
What Is The Best Time To Property Buy For Rent?
deneme bonusu veren siteler yeni: deneme bonusu veren siteler yeni – deneme bonusu veren siteler 2024
Приобретение школьного аттестата с официальным упрощенным обучением в Москве
Приобретение диплома ПТУ с сокращенной программой обучения в Москве
Узнайте, как безопасно купить диплом о высшем образовании
Как безопасно купить диплом колледжа или ПТУ в России, что важно знать
denemebonusuverensiteler.top https://ultrabet-tr.online/# ultrabet yeni giris 1125
Casino Siteleri: Casino Siteleri – casino siteleri win
guvenilir casino siteleri Deneme Bonusu Veren Siteler Casino Siteleri
промокод геткурс http://www.platezhnyj-modul-getkurs-promokod.ru/ .
Phosphoric acid. Ootd meaning. Coyote. Space needle. Robert redford. Gisele bundchen. Sp 500. Scrapple. Leukopenia. Joseph smith. Espionage. Heart diagram. Chives. Patrick mahomes career stats. Brave new world. Anthony kiedis. Truman show. Femur. Xray. Women’s world cup. Broom. Dick. Curacao. Scimitar meaning. Rules of engagement. Liam neeson movies. Studio 54. Judy garland. Catatonia. The boogeyman. Rib. Solidarity. New testament. Convergent evolution. Bowdoin college. Prince harry. duke of sussex. Saddam hussein. Discrepancy. Mica. West. Anise. Jane austen. Spark notes. Water buffalo. Jim crow laws. Jim carrey. Tanya chutkan. Consummate. Amine. Claudia sheinbaum. I am sam. https://2025.uj74.ru/TCUHW.html
Names. Fred astaire. Zoe kravitz. Him. Socket wrench. Gettysburg. Bongo. Treasury bill rates. Bolognese. Tab. Pete alonso. Kintsugi. Oppenheimer movie. Norwegian elkhound. Forte. Elizabeth taylor. Rhombus. Ri. Corn. Nsaid. India national cricket team vs pakistan national cricket team timeline. Occidental college. Dallas mavericks vs okc thunder timeline. Nationalism. Hearts card game online. Unequivocally. Argentina national football team. Aspirin. Inevitable. Spark plugs. Cornstarch. Sunbelt. Transmission. Museum of science and industry. Palindrome. Cape may. Aegis. Free guy. Starling. Aggregate. Stars. Trazodone. Back. Pantothenic acid. Lil kim. La confidential. Projector. Astrology chart. Fox. Dallas mavericks.
Платежный модуль геткурс промокод platezhnyj-modul-getkurs-promokod.ru .
ultrabet yeni giris 1125 ultrabet yeni giris 1125 ultrabet
When you are buying a property in Vienna , it is not just about interior design, the number of rooms or windows. Choosing the view from the windows is more.
Millie bobby brown. Conor mcgregor. Tranquility. Middle east. Wilmington nc. Chain store. Energy drink. Malaise. Delinquent. Castle. Vivek ramaswamy. Mantra. Human skeleton. Contiguous. Bolognese. King richard. Alliteration definition. Lambeau field. Elvis presley. Rider university. Molasses. The great gatsby. Viva la vida. Gray. The lost boys. Scorpio dates. Nucleotide. Die hard 2. Definition. Hurricane katrina. Lemon shark. John travolta movies. Frog. Paranoid. Maple tree. Dow jones industrial. Sickle cell anemia. Winter solstice. Wichita falls. Hemingway. Privy. David lynch. Earl. Solace meaning. Tampa bay rays. Obj. Jaded. Rip. Contentious. Juneau alaska. Thor 2011. https://2025.uj74.ru/PKBTL.html
Bonnie and clyde. Google coom. Scarlett johansson. Aries dates. Bridget jones diary. Decade. Buffy the vampire slayer. Nagasaki. Prostate cancer symptoms. Pittsburgh pirates games. Crazy horse. Gen alpha. Leonard bernstein. Interesting synonym. Eggs benedict. Salma hayek filmography. Purdue. The magnificent seven. Cujo. Epa. Carey mulligan movies. Arbitration. Roosevelt island. Fuck. Get out. Barbara stanwyck. Narnia. South america map. Francis ford coppola. Prevalent. Invidious. Ludacris. Mount vernon. Hymen. Christopher reeve. Stanford. Manifest. Catch 22. Hypomania. Disenchantment. Stock market crash. Caveat. Young frankenstein. Nun. Rich. Mark ruffalo movies. Ganesha. Saving private ryan. Grover cleveland. Hoo. Cherry tree. North pole. Watkins glen state park. Giganotosaurus. When is fathers day.
Milwaukee bucks standings. Hair. Angelina jolie movies list. Sam houston state university. Implement. Jeremy allen white movies and tv shows. The lego movie. University of hawaii. Cortisol. Eosinophils. Charlotte hornets. As roma. Power. The irishman. Monsters vs aliens. Kingfisher. Dopamine. Florence henderson. Jockey. Schitts creek. Water softener. Qantas. Fairfield university. The atlantic. September. Hell. Step brothers cast. Penny marshall. Astrological sign. Epic theater. Jeff daniels. Dakota. Downtown chicago. Jesse eisenberg. Badgers. Freud. Beads. Nuclear energy. Collateral. Nhs. Blue moon 2023. Marley and me. Bon scott. Ta. Online. Kathy griffin. https://2025.uj74.ru/ZWVGJ.html
0. Jade. Balloon. Film. Tom jones. Softball. Oman. Gq. 2024 solar eclipse path and times. Myanmar. Genghis khan. University of utah. Squash. White lotus. Bill maher. Youtobe. Mcculloch v maryland. Monster movie. Wecrashed. Florence henderson. North korea. Kelly clarkson. Abscess. Succulents. Greenland shark. Dartmouth college. Xanadu. Khaki pants. Puerto rican. Suez canal. Golden girls cast. Plumeria. Rbc. Issey miyake. Room and board. Lentil. University of washington. Mullet. Woodpecker. Senator menendez. Serval. The marvelous mrs. maisel. Thandie newton. Dog day afternoon. Michelle pfeiffer. Arab. Solace meaning. Plutonium. Dred scott. Nightshade. Sahara desert. Scapegoat. Lotus flower.
ultrabet tr online: ultrabet yeni giris 1125 – ultrabet guncel
купить диплом горного инженера servera-diplomy199.ru .
Платежный модуль Getcourse промокод http://platezhnyj-modul-getkurs-promokod.ru .