Bootstrap-Scrollspyプラグイン

スクロールスパイ（自動更新ナビゲーション）プラグインを使用すると、スクロール位置に基づいてページのセクションをターゲットにすることができます。基本的な実装では、スクロールしながら追加できます.active スクロール位置に基づいてナビゲーションバーにクラス分けします。

このプラグイン機能を個別に含めたい場合は、 scrollspy.js。それ以外の場合は、「ブートストラッププラグインの概要」の章で説明したように、 bootstrap.jsまたは縮小された bootstrap.min.jsを含めることができます。

使用法

トップバーのナビゲーションにスクロールスパイ動作を追加できます-

Via data attributes −追加 data-spy = "scroll"スパイしたい要素（通常は体）に。次に、属性を追加しますdata-target ブートストラップの親要素のIDまたはクラスを使用 .nav成分。これが機能するためには、スパイしているリンクのIDが一致する要素がページの本文に含まれている必要があります。

<body data-spy = "scroll" data-target = ".navbar-example">
   ...
   <div class = "navbar-example">
      <ul class = "nav nav-tabs">
         ...
      </ul>
   </div>
   ...
</body>

Via JavaScript −スパイする要素を選択してから呼び出すことにより、データ属性を使用する代わりにJavaScriptでscrollspyを呼び出すことができます。 .scrollspy() 関数-

$('body').scrollspy({ target: '.navbar-example' })

例

次の例は、データ属性を介したscrollspyプラグインの使用を示しています-

<nav id = "navbar-example" class = "navbar navbar-default navbar-static" role = "navigation">
   
   <div class = "navbar-header">
      <button class = "navbar-toggle" type = "button" data-toggle = "collapse" 
         data-target = ".bs-js-navbar-scrollspy">
         <span class = "sr-only">Toggle navigation</span>
         <span class = "icon-bar"></span>
         <span class = "icon-bar"></span>
         <span class = "icon-bar"></span>
      </button>
		
      <a class = "navbar-brand" href = "#">Tutorial Name</a>
   </div>
   
   <div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
      <ul class = "nav navbar-nav">
         <li><a href = "#ios">iOS</a></li>
         <li><a href = "#svn">SVN</a></li>
         
         <li class = "dropdown">
            <a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle = "dropdown">
               Java
               <b class = "caret"></b>
            </a>
            
            <ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
               <li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
               <li><a href = "#ejb" tabindex = "-1">ejb</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#spring" tabindex = "-1">spring</a></li>
            </ul>
            
         </li>
      </ul>
   </div>
   
</nav>

<div data-spy = "scroll" data-target = "#navbar-example" data-offset = "0" 
   style = "height:200px; overflow:auto; position: relative;">
   <h4 id = "ios">iOS</h4>
	
   <p>iOS is a mobile operating system developed and distributed by Apple 
      Inc. Originally released in 2007 for the iPhone, iPod Touch, and Apple 
      TV. iOS is derived from OS X, with which it shares the Darwin 
      foundation. iOS is Apple's mobile version of the OS X operating system 
      used on Apple computers.</p>
   
   <h4 id = "svn">SVN</h4>
   
   <p>Apache Subversion which is often abbreviated as SVN, is a software 
      versioning and revision control system distributed under an open source 
      license. Subversion was created by CollabNet Inc. in 2000, but now it 
      is developed as a project of the Apache Software Foundation, and as 
      such is part of a rich community of developers and users.</p>
   
   <h4 id = "jmeter">jMeter</h4>
   
   <p>jMeter is an Open Source testing software. It is 100% pure Java 
      application for load and performance testing.</p>
   
   <h4 id = "ejb">EJB</h4>
   
   <p>Enterprise Java Beans (EJB) is a development architecture for building 
      highly scalable and robust enterprise level applications to be deployed 
      on J2EE compliant Application Server such as JBOSS, Web Logic etc.</p>
   
   <h4 id = "spring">Spring</h4>
   
   <p>Spring framework is an open source Java platform that provides 
      comprehensive infrastructure support for developing robust Java 
      applications very easily and very rapidly.</p>
   
   <p>Spring framework was initially written by Rod Johnson and was first 
      released under the Apache 2.0 license in June 2003.</p>
   
</div>

オプション

オプションは、データ属性またはJavaScriptを介して渡すことができます。次の表にオプションを示します-

オプション名	タイプ/デフォルト値	データ属性名	説明
オフセット	番号デフォルト：10	データオフセット	スクロールの位置を計算するときに上からオフセットするピクセル。

メソッド

.scrollspy('refresh') − JavaScriptメソッドを介してscrollspyを呼び出す場合は、 .refreshDOMを更新するメソッド。これは、DOMの要素が変更された場合、つまり、いくつかの要素を追加または削除した場合に役立ちます。以下は、このメソッドを使用するための構文です。

$('[data-spy = "scroll"]').each(function () {
   var $spy = $(this).scrollspy('refresh')
})

例

次の例は、 .scrollspy('refresh') 方法−

<nav id = "myScrollspy" class = "navbar navbar-default navbar-static" role = "navigation">
   
   <div class = "navbar-header">
      <button class = "navbar-toggle" type = "button" data-toggle = "collapse" 
         data-target = ".bs-js-navbar-scrollspy">
         <span class = "sr-only">Toggle navigation</span>
         <span class = "icon-bar"></span>
         <span class = "icon-bar"></span>
         <span class = "icon-bar"></span>
      </button>
		
      <a class = "navbar-brand" href = "#">Tutorial Name</a>
   </div>
   
   <div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
      <ul class = "nav navbar-nav">
         <li class = "active"><a href = "#ios">iOS</a></li>
         <li><a href = "#svn">SVN</a></li>
         
         <li class = "dropdown">
            <a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle  = "dropdown">
               Java 
               <b class = "caret"></b>
            </a>
            
            <ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
               <li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
               <li><a href = "#ejb" tabindex = "-1">ejb</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#spring" tabindex = "-1">spring</a></li>
            </ul>
            
         </li>
      </ul>
   </div>
   
</nav>

<div data-spy = "scroll" data-target = "#myScrollspy" data-offset = "0"  
   style = "height:200px; overflow:auto; position: relative;">
   
   <div class = "section">
      <h4 id = "ios">iOS<small><a href = "#" onclick = "removeSection(this);">
         &times; Remove this section</a></small>
      </h4>
      
      <p>iOS is a mobile operating system developed and distributed by 
         Apple Inc. Originally released in 2007 for the iPhone, iPod Touch, and 
         Apple TV. iOS is derived from OS X, with which it shares the Darwin 
         foundation. iOS is Apple's mobile version of the OS X operating system
         used on Apple computers.</p>
   </div>
   
   <div class = "section">
      <h4 id = "svn">SVN<small></small></h4>
      <p>Apache Subversion which is often abbreviated as SVN, is a software 
         versioning and revision control system distributed under an open source 
         license. Subversion was created by CollabNet Inc. in 2000, but 
         now it is developed as a project of the Apache Software Foundation, 
         and as such is part of a rich community of developers and users.</p>
   </div>
   
   <div class = "section">
      <h4 id = "jmeter">jMeter<small><a href = "#" onclick = "removeSection(this);">
         &times; Remove this section</a></small>
      </h4>
      
      <p>jMeter is an Open Source testing software. It is 100% pure Java 
         application for load and performance testing.</p>
   </div>
   
   <div class = "section">
      <h4 id = "ejb">EJB</h4>
      
      <p>Enterprise Java Beans (EJB) is a development architecture for 
         building highly scalable and robust enterprise level applications 
         to be deployed on J2EE compliant Application Server such as 
         JBOSS, Web Logic etc.</p>
   </div>
	
   <div class = "section">
      <h4 id = "spring">Spring</h4>
      
      <p>Spring framework is an open source Java platform that provides 
         comprehensive infrastructure support for developing robust Java 
         applications very easily and very rapidly.</p>
      
      <p>Spring framework was initially written by Rod Johnson and was first 
         released under the Apache 2.0 license in June 2003.</p>
   </div>
   
</div>

<script type = "text/javascript">
   $(function(){
      removeSection = function(e) {
         $(e).parents(".section").remove();
         
         $('[data-spy = "scroll"]').each(function () {
            var $spy = $(this).scrollspy('refresh')
         });
      }
      $("#myScrollspy").scrollspy();
   });
</script>

イベント

次の表に、scrollspyで機能するイベントを示します。このイベントは、関数にフックするために使用できます。

イベント	説明	例
activate.bs.scrollspy	このイベントは、新しいアイテムがスクロールスパイによってアクティブ化されるたびに発生します。	`$('#myScrollspy').on('activate.bs.scrollspy', function () { // do something… })`

例

次の例は、 activate.bs.scrollspy イベント−

<html>
   <head>
      <link rel = "stylesheet" href = "bootstrap/css/bootstrap.min.css">
      <script src = "bootstrap/scripts/jquery.min.js"></script>
      <script src = "bootstrap/js/bootstrap.min.js"></script>
      
      <script>
         $(document).ready(function(){
            removeSection = function(e) {
               $(e).parents(".subject").remove();
            
               $('[data-spy="scroll"]').each(function () {
                  var $spy = $(this).scrollspy('refresh')
               });
            }
         
            $("#Navexample").scrollspy();
         
            // The event is fired when an item gets actived with the scrollspy
            $("#Navexample").on('activate.bs.scrollspy', function () {
               var currentSection = $(".nav li.active > a").text();
               $("#spyevent").html("Current Item being viewed >> " + currentSection);
            })
				
         });
      </script>
   
      <style>
         .scroll-box {
            height: 250px;
            position: relative;
            overflow: auto;
            font-size:2em;
         }
      </style>
   </head>
   
   <body>
      <div class = "container">
         <nav id = "Navexample" class = "navbar navbar-default" role = "navigation">
      
            <!-- Nav Bar -->
            <div class = "navbar-header">
               <button type = "button" class = "navbar-toggle" 
                  data-toggle = "collapse" data-target = "#navbarCollapse">
               
                  <span class = "sr-only">Toggle navigation</span>
                  <span class = "icon-bar"></span>
                  <span class = "icon-bar"></span>
                  <span class = "icon-bar"></span>
               </button>
					
               <a class = "navbar-brand" href = "#">Tutorials Point</a>
            </div>
            
            <!-- Links and Sublinks -->
            <div class = "collapse navbar-collapse" id = "navbarCollapse">
               <ul class = "nav navbar-nav">
                  <li class = "active"><a href = "#subject-1">Subject 1</a></li>
                  <li><a href = "#subject-2">Subject 2</a></li>
               
                  <li class = "dropdown"><a href = "#" class = "dropdown-toggle" 
                     data-toggle = "dropdown">Subject 3<b class = "caret"></b></a>
                     
                     <ul class = "dropdown-menu">
                        <li><a href = "#subject-3-1">Subject 3.1</a></li>
                        <li><a href = "#subject-3-2">Subject 3.2</a></li>
                        <li><a href = "#subject-3-3">Subject 3.3</a></li>
                     </ul>
                     
                  </li>
						
                  <li><a href = "#subject-4">Subject 4</a></li>
               </ul>
            </div>
            
         </nav>
         
         <div class = "scroll-box" data-spy = "scroll" data-offset = "0">
            <div class = "subject">
            
               <h3 id = "subject-1">Subject 1 
                  <small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
               </h3>
            
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
				
            <hr>
         
            <div class = "subject">
               <h3 id = "subject-2">Subject 2 
                  <small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
               </h3>
            
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
				
            <hr>
         
            <div class = "subject">
               <h3 id = "subject-3">Subject 3 
                  <small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
               </h3>
            
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><
            </div>
				
            <hr>
            
            <div class = "subject">
               <h4 id = "subject-3-1">Subject 3.1
                  <small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
               </h4>
               
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
            
            <div class = "subject">
               <h4 id = "subject-3-2">Subject 3.2
                  <small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
               </h4>
               
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
            
            <div class = "subject">
               <h4 id = "subject-3-3">Subject 3.3 
                  <small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
               </h4>
               
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
				
            <hr>
            
            <div class = "subject">
               <h3 id = "subject-4">Subject 4 
                  <small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
               </h3>
               
               <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
                  sed do eiusmod tempor incididunt ut labore et dolore magna
                  aliqua. Ut enim ad minim veniam, quis nostrud exercitation
                  ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
            </div>
            
         </div>
         <hr>
         
         <h4 id = "spyevent" class = "text-info"></h4>
      </div>
   </body>
</html>