vue元件
fetch請求元件
fetch
XMLHttpRequest是一個設計粗糙的API, 配置和呼叫方式非常混亂,而且基於事件的非同步模型寫起來不友好,相容性不好.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script type="text/javascript" src="lib/vue.js"></script>
</head>
<body>
<div id="box">
<button @click="handleClick()">獲取影片資訊</button>
<ul>
<li v-for="data in datalist">
<h3>{{ data.name }}</h3>
<img :src="data.poster">
</li>
</ul>
</div>
<script>
new Vue({
el: "#box",
data: {
datalist: []
},
methods: {
handleClick() {
fetch("./json/test.json").then(res => res.json()).then(res => {
console.log(res.data.films)
this.datalist = res.data.films
})
}
}
})
</script>
<!-- new Vue({
el: "#box",
data:{
datalist:["111","222","333"]
}
}) -->
</body>
</html>
axios請求元件
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>
<script type="text/javascript" src="lib/vue.js"></script>
</head>
<body>
<div id="box">
<button @click="handleClick()">正在熱映</button>
<ul>
<li v-for="data in datalist">
<h1>{{ data.name }}</h1>
<img :src="data.poster">
</li>
</ul>
</div>
<script>
new Vue({
el: "#box",
data: {
datalist: []
},
methods: {
handleClick() {
axios.get("./json/test.json").then(res => {
// axios 自歐東包裝data屬性 res.data
console.log(res.data.data.films)
this.datalist = res.data.data.films
}).catch(err => {
console.log(err);
})
}
}
})
</script>
</body>
</html>
vue計算屬性
/*
複雜邏輯,模板難以維護
1. 基礎例子
2. 計算快取 VS methods
- 計算屬性是基於他們的依賴進行快取的.
- 計算屬性只有在他的相關依賴發生改變時才會重新求值
3. 計算屬性VS watch
- v-model
*/
Example1
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script type="text/javascript" src="lib/vue.js"></script>
</head>
<body>
<div id="box">
<!-- 擷取myname字串將首字母大寫,不推薦,請看下面 -->
{{ myname.substring(0,1).toUpperCase() + myname.substring(1) }}
<!-- 不要加(),否則就是函式 -->
<p>計算屬性:{{ getMyName }}</p>
<p>普通方法:{{ getMyNameMethod() }}</p>
<div>
也需要計算結果
<p>計算屬性:{{ getMyName }}</p>
<!-- 計算屬性可以讓一個頁面多個地方呼叫一個計算結果只呼叫一次,而方法多次呼叫會多次執行 -->
<!-- 1. 依賴的狀態改變了, 計算屬性會重新計算一遍
2. 計算屬性會快取 -->
<p>普通方法:{{ getMyNameMethod() }}</p>
</div>
</div>
<script>
vm = new Vue({
el: "#box",
data: {
myname: "xiaoming"
},
methods:{
getMyNameMethod(){
console.log("getMyNameMethos-方法呼叫")
return this.myname.substring(0,1).toUpperCase() + this.myname.substring(1) }
},
computed:{
getMyName(){
console.log("getMyName-計算屬性呼叫")
return this.myname.substring(0,1).toUpperCase() + this.myname.substring(1)
}
}
})
</script>
</body>
</html>
Example2
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script type="text/javascript" src="lib/vue.js"></script>
</head>
<body>
<div id="box">
<input type="text" v-model="mytext" />
<!-- <input type="text" @input="handleInput()" v-model="mytext" /> -->
<ul>
<li v-for="data in getMyDatalist">
{{ data }}
</li>
</ul>
</div>
<script type="text/javascript">
var vm = new Vue({
el: "#box",
data: {
mytext: "",
datalist: ["aaa", "bbb", "ccc", "ddd", "eee", ],
},
computed: {
getMyDatalist() {
return this.datalist.filter(item => item.indexOf(this.mytext) > -1)
}
},
})
</script>
</body>
</html>
vue元件
元件（Component）是 Vue.js 最強大的功能之一。
元件可以擴充套件 HTML 元素，封裝可重用的程式碼。
元件系統讓我們可以用獨立可複用的小元件來構建大型應用，幾乎任意型別的應用的介面都可以抽象為一個元件樹：
全域性元件
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script type="text/javascript" src="lib/vue.js"></script>
<style>
.navbar{
background: red;
}
</style>
</head>
<body>
<div id="box">
<navbar></navbar>
<navbar></navbar>
</div>
<script type="text/javascript">
// 1. 全域性定義元件(作用域隔離)
Vue.component("navbar", {
template: `
<div style="background:yellow">
<button @click="handleback()">返回</button>
navbar
<button>主頁</button>
</div>`,
methods: {
handleback() {
console.log("back")
}
}
})
new Vue({
el: "#box"
})
</script>
</body>
</html>