Paginating A List

Adding pagination to a SS_List is quite simple. All you need to do is wrap the object in a PaginatedList decorator, which takes care of fetching a sub-set of the total list and presenting it to the template.

In order to create a paginated list, you can create a method on your controller that first creates a SS_List that will return all pages, and then wraps it in a PaginatedList object. The PaginatedList object is also passed the HTTP request object so it can read the current page information from the "?start=" GET var.

The paginator will automatically set up query limits and read the request for information.

/**
 * Returns a paginated list of all pages in the site.
 */
public function PaginatedPages() {
    return new PaginatedList(Page::get(), $this->request);
}

Note that the concept of "pages" used in pagination does not necessarily mean that we're dealing with Page classes, its just a term to describe a sub-collection of the list.

Setting Up The Template

Now all that remains is to render this list into a template, along with pagination controls. There are two ways to generate pagination controls: PaginatedList->Pages() and PaginatedList->PaginationSummary(). In this example we will use PaginationSummary().

The first step is to simply list the objects in the template:

<ul>
    <% loop $PaginatedPages %>
        <li><a href="$Link">$Title</a></li>
    <% end_loop %>
</ul>

By default this will display 10 pages at a time. The next step is to add pagination controls below this so the user can switch between pages:

<% if $PaginatedPages.MoreThanOnePage %>
    <% if $PaginatedPages.NotFirstPage %>
        <a class="prev" href="$PaginatedPages.PrevLink">Prev</a>
    <% end_if %>
    <% loop $PaginatedPages.Pages %>
        <% if $CurrentBool %>
            $PageNum
        <% else %>
            <% if $Link %>
                <a href="$Link">$PageNum</a>
            <% else %>
                ...
            <% end_if %>
        <% end_if %>
        <% end_loop %>
    <% if $PaginatedPages.NotLastPage %>
        <a class="next" href="$PaginatedPages.NextLink">Next</a>
    <% end_if %>
<% end_if %>

If there is more than one page, this block will render a set of pagination controls in the form [1] ... [3] [4] [[5]] [6] [7] ... [10].

Paginating Custom Lists

In some situations where you are generating the list yourself, the underlying list will already contain only the items that you wish to display on the current page. In this situation the automatic limiting done by PaginatedList will break the pagination. You can disable automatic limiting using the PaginatedList->setLimitItems() method when using custom lists.

Related

• Howto: "Grouping Lists"