Integrating Bootstrap Pagination with Ghost

In my previous post, I discussed how to integrate Bootstrap into the default Ghost theme. This post will cover the way that I modified pagination to use Bootstrap's pagination control.

To start, you will need to create a new pagination.hbs file in the partials folder in the root of your theme.

Because of the way that Bootstrap pagination works, I had to implement pagination using client-side JavaScript. The implementation uses a combination of server-side handlebars markup and client-side script.

The variables that we'll use in the pagination are defined in the site-init.js file in /assets/js.

var prev;
var pages;
var page;
var next;
var pageUrl;
var pageUrlPrev;
var pageUrlNext;
var numbersSurroundingEllipses = 3;
var useSimplePagination = false;

Here is the pagination.hbs for the customized pagination that I am using on my site:

<script type="text/javascript">
	// set the values that we'll use in the bootstrap-pagination.js file
	{{!if there is no value for the variable, display a 0}}
	prev = {{#if prev}}{{prev}}{{else}}0{{/if}};
	pages = {{#if pages}}{{pages}}{{else}}0{{/if}};
	page = {{#if page}}{{page}}{{else}}0{{/if}};
	next = {{#if next}}{{next}}{{else}}0{{/if}};
	pageUrl = '{{page_url}}';
	pageUrlPrev = '{{pageUrl prev}}';
	pageUrlNext = '{{pageUrl next}}';
	pageUrlFirst = '{{pageUrl 1}}';
	pageUrlLast = '{{pageUrl pages}}';
</script>
<nav>
  <ul class="pagination bootstrap-pagination">
  </ul>
</nav>

This particular bit of code is a little confusing at first glance because it combines client- and server-side script. Let's break it down.

Since this code will appear each time the pagination control is displayed, we don't want to define the variables here. That's why they were defined in the init script file. So, each time the code runs on the page, it will set the value of the variables needed to create the pagination control.

Notice the if statements. Since these values may be empty, we can't just use them "raw" to define the values of our JavaScript variables. This will lead to a JavaScript error because essentially, an empty value would render the following code:

prev = ;

This is obviously incorrect. The {{#if prev}}{{prev}}{{else}}0{{/if}}; code will check to see if we have the prev variable defined. If so, we'll simply print it out. If not, we'll provide the number 0. It then repeats this process for the remaining initialization variables.

After the initialization code, we just create a nav control with the ul defined. It is empty when it is defined. In order to fill it with page navigation controls, we will use jQuery code when the document is ready.

The main default.hbs file includes a link to the pagination script. Here is the code that runs when the page starts up:

$(document).ready(function() {	
	// see if there are any previous pages
	// if so, append them to the pagination ul
	if (prev > 0) {
		$('ul.bootstrap-pagination').append('<li class="prev"><a href="' + pageUrlFirst + '" title="Go to first page" aria-label="First"><span aria-hidden="true"><i class="fa fa-angle-double-left"></i></i></span></a></li>');
		$('ul.bootstrap-pagination').append('<li class="prev"><a href="' + pageUrlPrev + '" title="Go to previous page" aria-label="Previous"><span aria-hidden="true"><i class="fa fa-angle-left"></i></span></a></li>');
	}
	
	if (useSimplePagination) {
		doSimplePagination();
	}
	else {
		doComplexPagination();
	}
	
	// if we have pages after this one, display the 'next' buttons
	if (next > 0) {
		$('.bootstrap-pagination').append('<li class="nxt"><a href="' + pageUrlNext + '" title="Go to next page" aria-label="Next"><span aria-hidden="true"><i class="fa fa-angle-right"></i></span></a></li>');
		$('ul.bootstrap-pagination').append('<li class="nxt"><a href="' + pageUrlLast + '" title="Go to last page" aria-label="Last"><span aria-hidden="true"><i class="fa fa-angle-double-right"></i></i></span></a></li>');
	}
});

As you can see, this code will add the navigate to first and navigate to previous buttons if we are not on the first page. It does this by using jQuery selectors to find any ul's on the page that use the .bootstrap-pagination class and appends the li controls that have the proper links.

Then, it checks to see if it should perform simple or complex pagination. Simple pagination merely shows "Page X of Y". Complex pagination shows the page numbers with an ellipses in the middle.

Simple pagination is performed by the following function:

function doSimplePagination() {
	$('.bootstrap-pagination').append('<li><a href="' + pageUrl + 'page/"' + page + '" aria-label="Page ' + page + ' of ' + pages + '">Page ' + page + ' of ' + pages + '</a></li>');
}

This shows the user what page they're on.

Complex pagination shows a set number of page numbers on either side of an ellipses. The number of page numbers to show is determined by the variable numbersSurroundingEllipses. This value is set in the init script to a default value of 3.

It is possible to override this number on the Settings->Code Injection screen on your site's dashboard. If the value is set to -1, then the pagination control will display all page numbers.

The code to determine which pages to display on the control is a bit complicated. In short, it will show the number of pages as defined by the numbersSurroundingEllipses variables and the page directly before and after the current page so that you can navigate between pages. When you get within a certain number of pages from the end (calculated based on the pages - (numbersSurroundingEllipses * 2) calculation), the ellipses is not shown and a link to the page in the "middle" is displayed.

Refer to the doComplexPagination() function in the bootstrap-pagination.js file.

The very last thing we do when creating the pagination control is set the current page as active:

$('li.page' + page).addClass('active');

This provides you with Bootstrap pagination on your Ghost blog.

Here is a screenshot of the pagination control:

Simple Pagination:

Complex Pagination:

Note: This implementation requires a link to FontAwesome fonts (used in the left and right buttons).

To make this work, make sure you remove (or alter) any CSS in your theme's screen.css file that might define properties on the nav element or the pagination class. I had a terrible time getting this working at first because the default theme heavily customizes these elements and has class names that clash with Bootstrap.