jQuery

Let's control our webpage!

Presentor:  Flower, YoYo

Date:  2018-11-29

Link:  https://goo.gl/7zntkd

What would we do today?

Notes

更厲害的！

https://goo.gl/v5NYjY

Remember JS?

大家應該都忘了吧Q
來幫大家複習個：
http://slides.com/jerryshey/javascript

However...

該怎麼讓網頁上的東西(element)動起來呢?

1. 先選取那個element，也可以是一個group

2. 想對它做什麼事

>///<

Some example

If we write in vanilla.js

(也就是沒有使用任何套件、框架、函式庫的js)

1. select by tag     (multiple)

document.getElementsByTagName("p")

3. select by id        (single)

document.getElementById("super")

2. select by class (multiple)

document.getElementsByClassName("super")

QAQ

The only powerful I found

1. select by selector   (single)

document.querySelector('<selector>')

2. select by selector   (multiple)

document.querySelectorAll('<selector>')

Still too long to memorize

We DO need a candy

jQuery

What is jQuery?

https://jquery.com

A JavaScript Library, it simplifies the mentioned queries.

Furthermore, it extends some basic function of JavaScript.

Hands On

啊！ selector 都忘了

幫大家複習，來找東西吃囉！

Usage

$('<selector>')

1. select an element

Usage

$('<selector>').methodName();

2. After selecting an element, you'll need to deal with it.

What action we would like to do?

add, update, delete, traversal

Add

$('<parent_element>').append(<child_element>);

$('<child_element>').appendTo(<parent_element>);

Child is added to the parent

Parent adds child

Update

$('<input_selector>').val(<value>);

$('<selector>').html(<everything>);

$('<selector>').text('<plain_text>');

Only for tag <input>, <textarea>,  and so on.

The common usage

Delete

$('<selector>').remove();

It's easy, just call

Traversal

$('<parent_selector>').find('<child_selector>');

$('<parent_selector>').children('<child_selector>');

$('<child_selector>').parent('<parent_selector>');

$('<child_selector>').parents('<parent_selector>');

$('<selector>').siblings('<brother_selector>');

Find children (children找兒女，find會一直找到曾曾...孫)

Find parents (parent找父母，parents會一直找到曾祖...父母)

Find siblings (找兄弟姊妹平輩)

How to include JQuery?

// 給個範例？
<script src="//code.jquery.com/jquery-3.1.1.min.js"></script>

Let's go!

Part II

Demo

https://jsfiddle.net/st880221/5k70jjt1/

Simple Notelist

HTML Skeleton

<div id="main">
  <div class="form">
    <div class="field">
      <input type="text" name="work" id="input-note" placeholder="Please enter something..."/>
      <button id="btn-add">Submit</button>
    </div>
  </div>
  <div id="note-list">
    <div class="item" id="note-template">
      <span class="text">我是一個範例的note</span>
      <span class="action">
        <button class="btn-edit">edit</button>
        <button class="btn-delete">delete</button>
      </span>
    </div>
  </div>
</div>

CSS

body {
  background: #ccc;
}

#main {
  width: 400px;
}

#note-template {
  /*display: none;*/
}

.form .field {
  display: flex;
  width: 100%;
}

.form .field input {
  display: flex;
  width: 100%;
}

.item {
  position: relative;
  margin-bottom: 4px;
  min-height: 24px;
  max-height: 24px;
}

.item .text {
  position: absolute;
  height: 40px;
  line-height: 40px;
  top: 0;
  left: 0;
  bottom: 0;
  padding: 0 5px;
}

.item .action {
  position: absolute;
  top: 5px;
  right: 0;
  bottom: 0;
}

Get "Ready"

$(document).ready(function() {
  /*
    When code start to execute from here, it indicates that every HTML element is ready.
    That is, you can manipulate them as your expect.
    
    Therefore, you should write down your code here this time and almost time.

    Such as click events of buttons, manipulating elements, 
    activating plugins and so on.

  */
});

Append a new note - step 1

// Bind the click event to addButton 
$("#btn-add").click(function() {
  submit();
});  

// After clicking the button, it should submit.
function submit() {
  // 1. Get the value of input
  var note = $("#input-note").val();

  // 2. if the value is blank, it should not be used;
  if (note === '') {
    alert("Please type something...");
    return;
  }

  // 3. Append the note
  appendNote(note);

  // 4. Reset the input
  clearInput();
}
  function appendNote(note) {
    // First, print out the note we are going to append.
    console.log("new note: ", note);

    /*
      Second, we are going to create a note element.
      Since there is a template already,
      we can clone it and use it without recreating;
      however, don't forget to remove "id", because the attribute "id" should be unique.
    */
    var newNote = $("#note-template").clone().removeAttr("id");

    // Third, find the "text" part and modify its value
    newNote.find(".text").text(note);

  }

Append a new note - step 2

  function appendNote(note) {
    var newNote = $("#note-template").clone().removeAttr("id");
    newNote.find(".text").text(note);
    
    // At this time, we append a new note to the list ^_^.
    newNote.appendTo("#note-list");
    // Or you can use $("#note-list").append(newNote);
  }

Append a new note - step 3

  function appendNote(note) {
    var newNote = $("#note-template").clone().removeAttr("id");
    newNote.find(".text").text(note);

    /*
      However, we missed some function, "edit" and "delete".
      First, bind the click event to both buttons.
    */
    newNote.find(".action .btn-edit").click(function() {
      // The keyword 'this' indicates the element which triggers the function.
      console.log("this: ", this);
      modifyNote(this);  
    });
    newNote.find(".action .btn-delete").click(function() {
      deleteNote(this);
    });

    newNote.appendTo("#note-list");
  }

Append a new note - step 4

// A basic function with name (具名函數)
function sayHi() {
  return "Hi";
}
sayHi();

// Basic function definition
// A anonymous function (匿名函數)
var sayHi = function() {
  return "Hi";
}
$("#btn").click(sayHi);

// One common use for anonymous functions is as arguments to other function.

Extra: JS function

  function modifyNote(target) {
    // "target" is from the 'this' of click callback

    // Show a popup and ask you to enter a new value.
    var new_note_text = prompt();

    // If there is text, assign it to the note text.
    if (new_note_text != "") {
      $(target).parents(".item").find(".text").text(???);
    }
  }

Modify a existed note


  function deleteNote(target) {
    $(target).parents(".item").remove();
  }

Delete a existed note

 function clearInput() {
   // Try it.
 }

Reset Input

  // And some convenience, bind the keypress event to input
  $("#input-note").keypress(function(e) {
    var keycode = e.keyCode;
    // The number 13 represents the "enter" on your keyboard!!
    if (keycode == 13) {
      submit();
    }
  })

Make append easily

Too plain? Let's make it beautiful!

https://jsfiddle.net/st880221/f6p6u69e/

A Notelist with Semantic UI

UI framework

http://semantic-ui.com/

UI framework

http://getbootstrap.com/

RWD-support UI framework

RWD: Responsive Web Design 響應式設計

https://www.wilai.tw/

UI Framework: 

AWD: Adaptive Web Design 適應式設計

https://www.facebook.com/

套用制式的排版、網格、元件、樣式，以幫助開發者快速構築畫面

Grid System

A modern web layout solution

 Split page into grid blocks in rows.

Then you may deal with your layout without mess pain.

Breakpoints

Bootstrap

Semantic

HTML Skeleton

<div class="ui stackable grid container">
  <div class="ui four wide column"></div>
  <div class="ui eight wide column">
    <div class="ui segments">
      <div class="ui segment form">
        <div class="field">
          <label for="work"></label>
          <div class="ui action input">
            <input type="text" name="work" id="input-note" placeholder="Please enter something..."/>
            <div type="submit" class="ui teal submit button btn-submit">Submit</div>
          </div>
        </div>
      </div>
      <div class="ui segment">
        <div id="note-list"></div>
      </div>
    </div>
  </div>
  <div class="ui four wide column"></div>
</div>

<div class="item" id="note-template">
  <div class="text">我是一個範例的item</div>
  <div class="action">
    <div class="ui circular blue icon button btn-edit">
      <i class="write icon"></i>
    </div>
    <div class="ui circular red icon button btn-delete">
      <i class="remove icon"></i> 
    </div>
  </div>
</div>

CSS

html, body {
  height: 100%;
}

body {
  background: linear-gradient(to left, #348F50 , #56B4D3);
  /* Use "display: flex" to align it */
}

#note-template {
  display: none;
  opacity: 0;
}

#note-list .item {
  /* Use "display: flex" to align it */
  position: relative;
  margin-bottom: 4px;
  height: 40px;
  border: 1px dashed #ddd;
  opacity: 1;
  animation: fadeIn .65s;
  -webkit-animation: fadeIn .65s;
}

.item .text {
  height: 40px;
  line-height: 40px;
  padding: 0 10px;
}

@keyframes fadeIn {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

Thanks

JQuery

By David Tsui

Source: Hao-You Hung

JQuery

by / Flower, YoYo | NCHUIT

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