# Buttons example Enable / disable

It can often be useful to be able to dynamically enable and disable buttons based on the document state and other components in the table. A typical example of this is to enable a button that will take action on a selected row in the table, only when there is a row selected! If there is no row selected, the button should not take any action when clicked upon (i.e. it is disabled).

This example makes use of the Select extension for DataTables to provide row selection. The `select` event it listened for to know when the row selection has changed and then update the button's enabled / disabled state through the `button().enable()` method.

The `button()` method is a selector method that will use the information given to it to select the buttons that the subsequent methods will take action on. There is also a `buttons()` method that can be used to select multiple buttons (the DataTables API makes significant use of this plural / singular distinction).

The `button-selector` used in this example is a simple index selector - button 1 and button 2. Based on the number of rows selected the enablement state is adjusted. The first button is enabled when there is only one row selected, the second when one or more rows are selected.

Note that the Select library provides a number of button types such as `selected` and `selectedSingle` that provide this enable / disabled option without the additional code shown in this example.

Name | Position | Office | Age | Start date | Salary
--- | --- | --- | --- | --- | ---
Name | Position | Office | Age | Start date | Salary
Tiger Nixon | System Architect | Edinburgh | 61 | 2011/04/25 | $320,800
Garrett Winters | Accountant | Tokyo | 63 | 2011/07/25 | $170,750
Ashton Cox | Junior Technical Author | San Francisco | 66 | 2009/01/12 | $86,000
Cedric Kelly | Senior Javascript Developer | Edinburgh | 22 | 2012/03/29 | $433,060
Airi Satou | Accountant | Tokyo | 33 | 2008/11/28 | $162,700
Brielle Williamson | Integration Specialist | New York | 61 | 2012/12/02 | $372,000
Herrod Chandler | Sales Assistant | San Francisco | 59 | 2012/08/06 | $137,500
Rhona Davidson | Integration Specialist | Tokyo | 55 | 2010/10/14 | $327,900
Colleen Hurst | Javascript Developer | San Francisco | 39 | 2009/09/15 | $205,500
Sonya Frost | Software Engineer | Edinburgh | 23 | 2008/12/13 | $103,600
Jena Gaines | Office Manager | London | 30 | 2008/12/19 | $90,560
Quinn Flynn | Support Lead | Edinburgh | 22 | 2013/03/03 | $342,000
Charde Marshall | Regional Director | San Francisco | 36 | 2008/10/16 | $470,600
Haley Kennedy | Senior Marketing Designer | London | 43 | 2012/12/18 | $313,500
Tatyana Fitzpatrick | Regional Director | London | 19 | 2010/03/17 | $385,750
Michael Silva | Marketing Designer | London | 66 | 2012/11/27 | $198,500
Paul Byrd | Chief Financial Officer (CFO) | New York | 64 | 2010/06/09 | $725,000
Gloria Little | Systems Administrator | New York | 59 | 2009/04/10 | $237,500
Bradley Greer | Software Engineer | London | 41 | 2012/10/13 | $132,000
Dai Rios | Personnel Lead | Edinburgh | 35 | 2012/09/26 | $217,500
Jenette Caldwell | Development Lead | New York | 30 | 2011/09/03 | $345,000
Yuri Berry | Chief Marketing Officer (CMO) | New York | 40 | 2009/06/25 | $675,000
Caesar Vance | Pre-Sales Support | New York | 21 | 2011/12/12 | $106,450
Doris Wilder | Sales Assistant | Sidney | 23 | 2010/09/20 | $85,600
Angelica Ramos | Chief Executive Officer (CEO) | London | 47 | 2009/10/09 | $1,200,000
Gavin Joyce | Developer | Edinburgh | 42 | 2010/12/22 | $92,575
Jennifer Chang | Regional Director | Singapore | 28 | 2010/11/14 | $357,650
Brenden Wagner | Software Engineer | San Francisco | 28 | 2011/06/07 | $206,850
Fiona Green | Chief Operating Officer (COO) | San Francisco | 48 | 2010/03/11 | $850,000
Shou Itou | Regional Marketing | Tokyo | 20 | 2011/08/14 | $163,000
Michelle House | Integration Specialist | Sidney | 37 | 2011/06/02 | $95,400
Suki Burks | Developer | London | 53 | 2009/10/22 | $114,500
Prescott Bartlett | Technical Author | London | 27 | 2011/05/07 | $145,000
Gavin Cortez | Team Leader | San Francisco | 22 | 2008/10/26 | $235,500
Martena Mccray | Post-Sales support | Edinburgh | 46 | 2011/03/09 | $324,050
Unity Butler | Marketing Designer | San Francisco | 47 | 2009/12/09 | $85,675
Howard Hatfield | Office Manager | San Francisco | 51 | 2008/12/16 | $164,500
Hope Fuentes | Secretary | San Francisco | 41 | 2010/02/12 | $109,850
Vivian Harrell | Financial Controller | San Francisco | 62 | 2009/02/14 | $452,500
Timothy Mooney | Office Manager | London | 37 | 2008/12/11 | $136,200
Jackson Bradshaw | Director | New York | 65 | 2008/09/26 | $645,750
Olivia Liang | Support Engineer | Singapore | 64 | 2011/02/03 | $234,500
Bruno Nash | Software Engineer | London | 38 | 2011/05/03 | $163,500
Sakura Yamamoto | Support Engineer | Tokyo | 37 | 2009/08/19 | $139,575
Thor Walton | Developer | New York | 61 | 2013/08/11 | $98,540
Finn Camacho | Support Engineer | San Francisco | 47 | 2009/07/07 | $87,500
Serge Baldwin | Data Coordinator | Singapore | 64 | 2012/04/09 | $138,575
Zenaida Frank | Software Engineer | New York | 63 | 2010/01/04 | $125,250
Zorita Serrano | Software Engineer | San Francisco | 56 | 2012/06/01 | $115,000
Jennifer Acosta | Junior Javascript Developer | Edinburgh | 43 | 2013/02/01 | $75,650
Cara Stevens | Sales Assistant | New York | 46 | 2011/12/06 | $145,600
Hermione Butler | Regional Director | London | 47 | 2011/03/21 | $356,250
Lael Greer | Systems Administrator | London | 21 | 2009/02/27 | $103,500
Jonas Alexander | Developer | San Francisco | 30 | 2010/07/14 | $86,500
Shad Decker | Regional Director | Edinburgh | 51 | 2008/11/13 | $183,000
Michael Bruce | Javascript Developer | Singapore | 29 | 2011/06/27 | $183,000
Donna Snider | Customer Support | New York | 27 | 2011/01/25 | $112,000

- Javascript
- HTML
- CSS
- Ajax
- Server-side script

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

`$(document).ready(function() { var table = $('#example').DataTable( { dom: 'Bfrtip', select: true, buttons: [ { text: 'Row selected data', action: function ( e, dt, node, config ) { alert( 'Row data: '+ JSON.stringify( dt.row( { selected: true } ).data() ) ); }, enabled: false }, { text: 'Count rows selected', action: function ( e, dt, node, config ) { alert( 'Rows: '+ dt.rows( { selected: true } ).count() ); }, enabled: false } ] } ); table.on( 'select', function () { var selectedRows = table.rows( { selected: true } ).count(); table.button( 0 ).enable( selectedRows === 1 ); table.button( 1 ).enable( selectedRows > 0 ); } ); } );`

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.buttons.js
- ../../../Select/js/dataTables.select.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/buttons.dataTables.css
- ../../../Select/css/select.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.