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Support Extra

This extra adds support for features like countless or navless pagination, where you don’t need the full link bar but only a simple next or prev link or no link at all (as for auto-incremental).

Synopsis

See extras for general usage info.

In the pagy.rb initializer:

require 'pagy/extras/support'

Support for alternative pagination types and features

Besides the classic pagy*_nav pagination, the pagy*_nav_js and the pagy*_combo_nav_js UI components, Pagy offers a few helpers to support a few alternative types of pagination and related features.

Countless

You can totally avoid one query per render by using the countless extra. It has a few limitation, but still supports navbar links (see also Pagy::Countless for more details).

If you don’t need the navbar you can just set the :size variable to an empty value and the page links will be skipped from the rendering. That works with Pagy and Pagy:Countless instances. All the *nav helpers will render only the prev and next links/buttons, allowing for a manual incremental pagination.

You can also use the pagy_prev_link and pagy_next_link helpers provided by this extra, mostly useful if you also use the countless extra.

Here is a basic example that use pagy_countless (saving one query per render):

pagy.rb initializer:

require 'pagy/extras/countless'

incremental controller action:

def incremental
  @pagy, @records = pagy_countless(Product.all, link_extra: 'data-remote="true"')
end

incremental.html.erb template:

<div id="content">
  <table id="records_table">
    <tr>
      <th>Name</th>
      <th>Description</th>
    </tr>
    <%= render partial: 'page_items' %>
  </table>
  <div id="div_next_link">
    <%= render partial: 'next_link' %>
  </div>
</div>

_page_items.html.erb partial shared for AJAX and non-AJAX rendering:

<% @records.each do |record| %>
  <tr>
    <td><%= record.name %></td>
    <td><%= record.description %></td>
  </tr>
<% end %>

_next_link.html.erb partial shared for AJAX and non-AJAX rendering:

<%== pagy_next_link(@pagy, 'More...', 'id="next_link"') %>

incremental.js.erb javascript template:

$('#records_table').append("<%= j(render 'page_items')%>");
$('#div_next_link').html("<%= j(render 'next_link') %>");

Auto-incremental

Automatic incremental pagination (sometimes improperly called “infinite-scroll” pagination) is a UI-less pagination that loads the next page at the end of the listing with an AJAX call.

We can implement it by using the same Incremental example above with just a couple of changes:

1. Hide the link in _next_link.html.erb by adding a style attribute:

<%== pagy_next_link(@pagy, 'More...', 'id="next_link" style="display: none;"') %>

2. Add a javascript that will click the link when the listing-bottom appears in the viewport on load/resize/scroll. It will keep the page filled with results, one page at a time:

var loadNextPage = function(){
  if ($('#next_link').data("loading")){ return }  // prevent multiple loading
  var wBottom  = $(window).scrollTop() + $(window).height();
  var elBottom = $('#records_table').offset().top + $('#records_table').height();
  if (wBottom > elBottom){
    $('#next_link')[0].click();
    $('#next_link').data("loading", true);
  }
};

window.addEventListener('resize', loadNextPage);
window.addEventListener('scroll', loadNextPage);
window.addEventListener('load',   loadNextPage);

Circular/Infinite

This type of pagination sets the next page to 1 when the current page is the last page, allowing an infinite loop through the pages.

For example, it is often used to show a few suggestions of “similar products” in a horizontal stripe of just a few pages of a few items each. Clicking on next will continue to loop through.

For example:

@pagy, @suggestions = pagy_countless(Product.all, count: 25, items: 5, cycle: true)

Passing a forced :count of 25 will generate 5 pages of 5 items each that will always have a next page. Regardless the actual collection count, you will show the first 25 items of the collection, looping in stripes of 5 items each.

You may want to combine it with something like:

<%== pagy_next_link(@pagy, 'More...') %>

Methods

pagy_prev_url(pagy)

Returns the url for the previous page. Useful to build minimalistic UIs that don’t use nav bar links (e.g. countless extra).

pagy_next_url(pagy)

Returns the url for the next page. Useful to build minimalistic UIs that don’t use nav bar links (e.g. countless extra).

Returns the link for the next page. It is the same prev link string which is part of the pagy_nav helper.

Useful to build minimalistic helpers UIs that don’t use nav bar links (e.g. countless extra).

Returns the link for the next page. It is the same next link string which is part of the pagy_nav helper.

Useful to build minimalistic helpers UIs that don’t use nav bar links (e.g. countless extra).