Angular directive for displaying a large number of items (100,000+) in a scrolling view.
scroll-repeat wraps Angular's ng-repeat directive, and provides optimized loading and unloading of on-screen and off-screen elements based on scroll position.
You can lay your items out any way you want, as long as they are all the same height and width. See our demo for some examples.
Get it with bower
bower install scroll-repeat
Reference the script
<script src="path/to/scroll-repeat.js"></script>
Add our module to your app
angular.module('myApp', ['litl']);
Use it just like you use ng-repeat
<div scroll-repeat="item in items">
<span>{{item.name}}</span>
</div>
When the browser's scroll position is changed too fast to keep up with the item rendering buffer, "clipping" may occur. You can detect when clipping occurs by watching the following properties:
// "top clipping" means items are missing from the top of the view
$scope.$watch('scrollRepeatClippingTop', function(val) {
// if val == true, top clipping is occuring
});
// "bottom clipping" means items are missing from the bottom of the view
$scope.$watch('scrollRepeatClippingBottom', function(val) {
// if val == true, bottom clipping is occuring
});
These properties can help you display an indication that items are being loaded.
scroll-repeat does not use isolated scope, so these properties are set on the scope where you define the directive.
Empty placeholders are shown when scrolling moves too fast to keep up with ng-repeat data binding. These can be styled with the scroll-repeat-item-placeholder class.
By default, these placeholder items have no content. Content for placeholders can be defined separately from the bound item template, by using scroll-repeat-item and scroll-repeat-placeholder:
<div scroll-repeat="item in items">
<div scroll-repeat-item>
// content for bound items
<span>{{item.name}}</span>
</div>
<div scroll-repeat-placeholder>
// content for placeholder items
<span>LOADING</span>
</div>
</div>
Install npm dependencies
npm install
Install bower dependencies
bower install
Run grunt
grunt
View the demo locally
http://localhost:8000
-
The more items you display on the screen at once, the larger the item buffer above and below the screen will be. This can result in performance issues if you try to cram too many items on the screen. The decrease in performance is especially noticable when using the scrollbar to make drastic jumps up and down the page.
-
Item offset position is calculated incorrectly on some mobile browsers (such as Safari for iOS) when scrolling causes the address bar to change width. This makes the items change position unexpectedly after scrolling comes to rest.