Framework7 - Infinite Scroll


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Description

The Infinite Scroll allows you to load additional content and performs the required actions when the page is near to the bottom.

The following HTML layout shows the infinite scroll −

<div class = "page">
   <div class = "page-content infinite-scroll" data-distance = "100">
      ...
   </div>
</div>

The above layout contains the following classes −

  • page-content infinite-scroll − It is used for infinite scroll container.

  • data-distance − This attribute allows you to configure distance from the bottom of page (in px) to trigger infinite scroll event and its default value is 50px.

If you want to use infinite scroll on top the page, you need to add additional "infinite-scroll-top" class to "page-content"

<div class = "page">
   <div class = "page-content infinite-scroll infinite-scroll-top">
      ...
   </div>
</div>

Infinite Scroll Events

infinite − It is used to trigger when page scroll reaches specified distance to the bottom. It will be target by div class = "page-content infinite-scroll".

There are two App's methods that can be used with infinite scroll container −

To add infinite scroll event listener to the specified HTML container, use the following method −

myApp.attachInfiniteScroll(container)

You can remove the infinite scroll event listener from the specified HTML container by using the following method −

myApp.detachInfiniteScroll(container)

Where parameters are required options used as HTMLElement or string for infinite scroll container.

Example

The following example demonstrates the infinite scroll that loads the additional content when the page scroll is near to the bottom −

<!DOCTYPE html>
<html>

   <head>
      <meta name = "viewport" content = "width = device-width, initial-scale = 1, 
         maximum-scale = 1, minimum-scale = 1, user-scalable = no, minimal-ui" />
      <meta name="apple-mobile-web-app-capable" content="yes" />
      <meta name = "apple-mobile-web-app-status-bar-style" content = "black" />
      <title>infinite_scroll</title>
      <link rel = "stylesheet" 
         href = "https://cdnjs.cloudflare.com/ajax/libs/framework7/1.4.2/css/framework7.ios.min.css" />
      <link rel = "stylesheet" 
         href = "https://cdnjs.cloudflare.com/ajax/libs/framework7/1.4.2/css/framework7.ios.colors.min.css" />
   </head>
   
   <body>
      <div class = "views">
         <div class = "view view-main">
         
            <div class = "navbar">
               <div class = "navbar-inner">
                  <div class = "left"> </div>
                  <div class = "center sliding">Infinite Scroll</div>
                  <div class = "right"> </div>
               </div>
            </div>
         
            <div class = "pages navbar-through">
               <div data-page = "home" class = "page">
                  <div class = "page-content infinite-scroll">
                     <div class = "list-block">
                        <ul>
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 1</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 2</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 3</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 4</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 5</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 6</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 7</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 8</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 9</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 10</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 11</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 12</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 13</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 14</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 15</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 16</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 17</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 18</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 19</div>
                              </div>
                           </li>
                        
                           <li class = "item-content">
                              <div class = "item-inner">
                                 <div class = "item-title">Item 20</div>
                              </div>
                           </li>
                        </ul>
                     </div>
                  
                     <div class = "infinite-scroll-preloader">
                        <div class = "preloader"></div>
                     </div>
                  </div>
               </div>
            </div>
         
         </div>
      </div>
      
      <script type = "text/javascript" 
         src = "https://cdnjs.cloudflare.com/ajax/libs/framework7/1.4.2/js/framework7.min.js"></script>
         
      <style>
         .infinite-scroll-preloader {
            margin-top:-20px;
            margin-bottom:10px;
            text-align:center;
         }
         
         .infinite-scroll-preloader .preloader {
            width:34px;
            height:34px;
         }
      </style>
      
      <script>
         var myApp = new Framework7();
         var $$ = Dom7;

         // Loading flag
         var loading = false;

         // Last loaded index
         var lastIndex = $$('.list-block li').length;

         // Max items to load
         var maxItems = 60;

         // Append items per load
         var itemsPerLoad = 20;

         // Attach 'infinite' event handler
         $$('.infinite-scroll').on('infinite', function () {

            // Exit, if loading in progress
            if (loading) return;

            // Set loading flag
            loading = true;

            // Emulate 1s loading
            setTimeout(function () {
               // Reset loading flag
               loading = false;

               if (lastIndex >= maxItems) {
                  // Nothing more to load, detach infinite scroll events to prevent unnecessary loadings
                  myApp.detachInfiniteScroll($$('.infinite-scroll'));
                  
                  // Remove preloader
                  $$('.infinite-scroll-preloader').remove();
                  return;
               }

               // Generate new items HTML
               var html = '';
               for (var i = lastIndex + 1; i <= lastIndex + itemsPerLoad; i++) {
                  html += '<li class = "item-content">
                     <div class = "item-inner">
                        <div class = "item-title">
                           Item ' + i + '
                        </div>
                     </div>
                  </li>';
               }

               // Append new items
               $$('.list-block ul').append(html);

               // Update last loaded index
               lastIndex = $$('.list-block li').length;
            }, 1000);
         });
      </script>
   </body>

</html>

Output

Let us carry out the following steps to see how the above given code works −

  • Save the above given HTML code as infinite_scroll.html file in your server root folder.

  • Open this HTML file as http://localhost/infinite_scroll.html and the output is displayed as shown below.

  • The example allows loading of additional content when your page scroll reaches specified distance to the bottom.



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