# Scroller example Basic initialisation

Scroller is a plug-in for DataTables which enhances DataTables' built-in scrolling features to allow large amounts of data to be rendered on page very quickly. This is done by Scroller through the use of a virtual rendering technique that will render only the part of the table that is actually required for the current view.

Note that Scroller requires that all rows are of the same height (in order to preform its positional calculations). You can use the `nowrap` class of the DataTables default stylesheet, or add `th, td { white-space: nowrap; }` to your CSS, to ensure that text in rows does not wrap.

This example shows how Scroller for DataTables can be initialised, when the Scroller Javascript file is included, by simply setting the `scroller` option to `true`. This option can also be given as an object to specify initialisation options for Scroller.

Deferred rendering (`deferRender`) should be used when Scroller is enabled to gain the speed benefits offered by Scroller. The data source for this example is an Ajax file (`ajax`).

ID | First name | Last name | ZIP / Post code | Country
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- Javascript
- HTML
- CSS
- Ajax
- Server-side script

The Javascript shown below is used to initialise the table shown in this example:

`$(document).ready(function() { $('#example').DataTable( { ajax: "../data/2500.txt", deferRender: true, scrollY: 200, scrollCollapse: true, scroller: true } ); } );`

In addition to the above code, the following Javascript library files are loaded for use in this example:

- //code.jquery.com/jquery-1.11.3.min.js
- ../../../../media/js/jquery.dataTables.js
- ../../js/dataTables.scroller.js

The HTML shown below is the raw HTML table element, before it has been enhanced by DataTables:

This example uses a little bit of additional CSS beyond what is loaded from the library files (below), in order to correctly display the table. The additional CSS used is shown below:

``

The following CSS library files are loaded for use in this example to provide the styling of the table:

- ../../../../media/css/jquery.dataTables.css
- ../../css/scroller.dataTables.css

This table loads data by Ajax. The latest data that has been loaded is shown below. This data will update automatically as any additional data is loaded.

The script used to perform the server-side processing for this table is shown below. Please note that this is just an example script using PHP. Server-side processing scripts can be written in any language, using the protocol described in the DataTables documentation.