Web frontend development

將會介紹...

  • Sublime Text 3
  • HTML
  • Javascript
  • CSS
  • web crawling

Sublime Text 3

https://www.sublimetext.com/3

安裝適合的版本

優點

  • 執行快速
  • 搜尋、取代功能(regular expression)
  • multiple selection(一次編輯多個地方)
  • syntax highlight
  • 插件(套件)多，可擴充大量功能
  • best editor for developers !!!

縮排控制

上色語言

CTRL+F 搜尋
CTRL+H 取代
CTRL+Shift+P 開啟指令介面
Esc 離開目前功能
CTRL+Click multiple selection

插件們

  • material theme

工具們

  • build system
  • snippet
  • terminus

build system

Tools > Build System > New Build System

snippets

Tools > Developer > New Snippet

material theme

CTRL+Shift+P > 

Package Control: Install Package > material theme

terminus

CTRL+Shift+P > 

Package Control: Install Package > terminus

HTML

HyperText Markup Language

超文字

標記

語言

HTML

what is HTML?

  • 標記語言
  • 告訴電腦物件的呈現方式
  • 不是程式語言！

基本語法

<TAGNAME>EXAMPLE</TAGNAME>

<html>
  <body>
    <h1>My First Heading</h1>
    <p>My first paragraph.</p>
  </body>
</html>

基本語法

<TAGNAME>

<img>
<input>
<br>
<link>
<meta>
<source>

基本語法

  • 無視換行
  • 多個空白會被視為一個
  • 檔案以\(\texttt{<!DOCTYPE>}\)開頭

All Tags

<!DOCTYPE>
Hello World!!!
I am new to HTML
<!DOCTYPE>
Hello World!!!<br>
I am new to HTML
<!DOCTYPE>
<h1>Hello World!!!</h1>
<p>I am new to HTML</p>
<!DOCTYPE>
<h1>heading1</h1>
<h2>heading2</h2>
<h3>heading3</h3>
<h4>heading4</h4>
<h5>heading5</h5>
<h6>heading6</h6>
<p>paragraph</p>
<!DOCTYPE>
<h1 style="color: red;">heading1</h1>
<h2 style="color: orange;">heading2</h2>
<h3 style="color: yellow;">heading3</h3>
<h4 style="color: green;">heading4</h4>
<h5 style="color: blue;">heading5</h5>
<h6 style="color: purple;">heading6</h6>
<p style="color: #808080;">paragraph</p>

基本語法

<TAGNAME ATTRIBUTE="VALUE"></TAGNAME>
<!DOCTYPE>
<h1 style="color: red;text-align:center">heading1</h1>
<h2 style="color: orange;text-align:center">heading2</h2>
<h3 style="color: yellow;text-align:center">heading3</h3>
<h4 style="color: green;text-align:center">heading4</h4>
<h5 style="color: blue;text-align:center">heading5</h5>
<h6 style="color: purple;text-align:center">heading6</h6>
<p style="color: #808080;text-align:center">paragraph</p>
<!DOCTYPE>
<h1 style="color: red;text-align: center;border-style: solid;">heading1</h1>
<h2 style="color: orange;text-align: center;border-style: solid;">heading2</h2>
<h3 style="color: yellow;text-align: center;border-style: solid;">heading3</h3>
<h4 style="color: green;text-align: center;border-style: solid;">heading4</h4>
<h5 style="color: blue;text-align: center;border-style: solid;">heading5</h5>
<h6 style="color: purple;text-align: center;border-style: solid;">heading6</h6>
<p style="color: gray;text-align: center;border-style: solid;">paragraph</p>

每個都寫一樣的東西

<!DOCTYPE>
<style>
  .text{
    text-align: center;
    border-style: solid;
  }
</style>
<h1 class="text" style="color: red;">heading1</h1>
<h2 class="text" style="color: orange;">heading2</h2>
<h3 class="text" style="color: yellow;">heading3</h3>
<h4 class="text" style="color: green;">heading4</h4>
<h5 class="text" style="color: blue;">heading5</h5>
<h6 class="text" style="color: purple;">heading6</h6>
<p class="text" style="color: gray;">paragraph</p>
讓所有 class 是 text 的 element 都加上
"text-align: center;border-style: solid;"
<!DOCTYPE>
<style>
  .text{
    text-align: center;
    border-style: solid;
  }
  .round{
    border-radius: 100px;
  }
</style>
<h1 class="text round" style="color: red;">heading1</h1>
<h2 class="text" style="color: orange;">heading2</h2>
<h3 class="text round" style="color: yellow;">heading3</h3>
<h4 class="text" style="color: green;">heading4</h4>
<h5 class="text round" style="color: blue;">heading5</h5>
<h6 class="text" style="color: purple;">heading6</h6>
<p class="text round" style="color: gray;">paragraph</p>
<!DOCTYPE>
<style>
  .text{
    text-align: center;
    border-style: solid;
  }
  .round{
    border-radius: 100px;
  }
</style>
<h1 class="text round" style="color: red;">heading1</h1>
<h2 class="text" style="color: orange;">heading2</h2>
<h3 class="text round" style="color: yellow;">heading3</h3>
<h4 class="text" style="color: green;">heading4</h4>
<h5 class="text round" style="color: blue;">heading5</h5>
<h6 class="text" style="color: purple;">heading6</h6>
<p class="text round" style="color: gray;">paragraph</p>

 CSS code

 CSS selector

<!DOCTYPE html>
<ol>
  <li>first</li>
  <li>second</li>
  <li>third</li>
</ol>
ordered list / list item
<!DOCTYPE html>
<ul>
  <li>first</li>
  <li>second</li>
  <li>third</li>
</ul>
unordered list / list item
<a href="https://slides.com/thomaswang2003/web">learn web</a>
<table style="width:100%">
  <tr>
    <th>Firstname</th>
    <th>Lastname</th>
    <th>Age</th>
  </tr>
  <tr>
    <td>Jill</td>
    <td>Smith</td>
    <td>50</td>
  </tr>
  <tr>
    <td>Eve</td>
    <td>Jackson</td>
    <td>94</td>
  </tr>
</table>

HTML 基本架構

蛤？現在才講？

<!DOCTYPE html>
<html>
<head>
  <title>jizz</title>
</head>
<body>
everything to be displayed on page
</body>
</html>

title

body

metas

<head>
  <meta charset="UTF-8">
  <meta name="description" content="INFOR Web-frontend jizz">
  <meta name="keywords" content="Sublime,HTML,CSS,Javascript,Web-crawling">
  <meta name="author" content="Thomas Wang">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>

最熟悉的工具—Google Chrome

F12

最重要的！Coding Style！

Cascading Style Sheets

CSS

CSS

what is CSS?

  • 設定每個元素、類別等的style
  • 將style與html分離
  • 類似「呈現與內容分離」的理念

selector 語法

/* select by element name */
ELEMENT {...}
/* select by class */
.CLASS {...}
/* select by id */
#id {...}
/* select all */
* {...}

selector 語法

/* select by element name */
h1 {font-weight: 1000;}
/* select by class */
.center {text-align: center;}
/* select by id */
#box {background-color: red;}
/* select all */
* {font-family: 'Noto Sans TC';}

border

margin

padding

display

position

CSS「框架」

其實就是函式庫

W3css

Bootstrap 4

Javascript

Javascript

what is JS?

  • 讓元素動起來
  • 處理事件(event)

基本語法 跟C++很像

  • 宣告變數用 \(\texttt{var}\)
  • 弱型別
  • \(\texttt{String}\)
  • \(\texttt{Number}\)
  • \(\texttt{Array}\)
  • \(\texttt{Object}\)
function double(x){
    x=String(x);
    return x+x;
}
console.log(double(7122))

HTML DOM

  • 更改HTML網頁的內容
  • 處理網頁發生事件
<!DOCTYPE html>
<html>
<head>
  <title></title>
</head>
<body>
<script>
  var x=7122;
  console.log(x);
  // js code goes here
</script>
</body>
</html>
document.getElementById
document.getElementsByTag
document.getElementsByClassName
<!DOCTYPE html>
<html>
<body>
  <h1 id="test">Testing Page</h1>
<script>
  var ele = document.getElementById('test');
  ele.innerHTML='Changed';
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<h1 class="text">heading1</h1>
<h2 class="text">heading2</h2>
<h3 class="text">heading3</h3>
<h4 class="text">heading4</h4>
<h5 class="text">heading5</h5>
<h6 class="text">heading6</h6>
<p class="text">paragraph</p>
<script>
  var eles = document.getElementsByClassName('text');
  console.log(eles.length);
  for(var i=0;i<eles.length;i++)
    eles[i].innerHTML='Changed';
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<h1 class="text">heading1</h1>
<h2 class="text">heading2</h2>
<h3 class="text">heading3</h3>
<h4 class="text">heading4</h4>
<h5 class="text">heading5</h5>
<h6 class="text">heading6</h6>
<p class="text">paragraph</p>
<button onclick="change();">Change</button>
<script>
  function change(){
    var eles = document.getElementsByClassName('text');
    console.log(eles.length);
    for(var i=0;i<eles.length;i++)
      eles[i].innerHTML='Changed';
  }
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<h1 class="text">heading1</h1>
<h2 class="text">heading2</h2>
<h3 class="text">heading3</h3>
<h4 class="text">heading4</h4>
<h5 class="text">heading5</h5>
<h6 class="text">heading6</h6>
<p class="text">paragraph</p>
<button id="btn">Change</button>
<script>
  function change(){
    var eles = document.getElementsByClassName('text');
    console.log(eles.length);
    for(var i=0;i<eles.length;i++)
      eles[i].innerHTML='Changed';
  }
  document.getElementById('btn').addEventListener('click',change);
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<h1 class="text">heading1</h1>
<h2 class="text">heading2</h2>
<h3 class="text">heading3</h3>
<h4 class="text">heading4</h4>
<h5 class="text">heading5</h5>
<h6 class="text">heading6</h6>
<p class="text">paragraph</p>
<button id="btn">Change</button>
<script>
  function double(x){
    x=String(x);
    return x+x;
  }
  function change(){
    var eles = document.getElementsByClassName('text');
    console.log(eles.length);
    for(var i=0;i<eles.length;i++)
      eles[i].innerHTML=double(eles[i].innerHTML);
  }
  document.getElementById('btn').addEventListener('click',change);
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<h1 class="text">heading1</h1>
<h2 class="text">heading2</h2>
<h3 class="text">heading3</h3>
<h4 class="text">heading4</h4>
<h5 class="text">heading5</h5>
<h6 class="text">heading6</h6>
<p class="text">paragraph</p>
<button id="btn1" onclick="change();">Change</button>
<button id="btn2" onclick="hide(this);">Hide</button>
<script>
  function double(x){
    x=String(x);
    return x+x;
  }
  function change(){
    var eles = document.getElementsByClassName('text');
    console.log(eles.length);
    for(var i=0;i<eles.length;i++)
      eles[i].innerHTML=double(eles[i].innerHTML);
  }
  function hide(x){
    if(x.innerHTML=='Hide'){
      x.innerHTML='Show';
      var eles = document.getElementsByClassName('text');
      console.log(eles.length);
      for(var i=0;i<eles.length;i++)
        eles[i].style.display='none';
    }else{
      x.innerHTML='Hide';
      var eles = document.getElementsByClassName('text');
      console.log(eles.length);
      for(var i=0;i<eles.length;i++)
        eles[i].style.display='block';
    }
  }
</script>
</body>
</html>

Web Crawler

網頁爬蟲

Web Crawler?

  • 從網路上「自動」抓取「大量」資料

如何從網路上取得資料

  • Request: 向伺服器請求
  • Response: 伺服器回傳的回應(檔案、資料...等)

請求有8種方法(method)

  • GET
  • POST
  • ...不重要

GET: 取得頁面(html css js image ...)

 

POST: 傳送資料(表單提交)

瀏覽器：向伺服器請求資料，

再呈現在畫面上

 

爬蟲：自己寫程式向伺服器請求資料

再進行資料處理

 

Python requests

import requests

response=requests.get('https://tioj.ck.tp.edu.tw')
print(response)
print(response.text)

缺了css

但我們不在乎

怎麼處理html code?

python bs4

from bs4 import BeautifulSoup as bs
code='<div><p>bs4</p></div>'
html=bs(code,'html.parser')
print(html.prettify())
print(html.select('div > p'))
print(html.select('div > p')[0].text)

利用selector找到你要的元素

然後擷取資料

website

By thomaswang2003

Made with Slides.com

website

  • 664

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