Webby ☯ Tips & Tricks

1Pagination

Pagination is the process of organizing information onto a page such that a fixed number of items appear on each page. Webby provides some methods for paginating information.

Let’s assume that your website has a collection of articles in a folder called “articles” in the content directory. The goal is to display these articles ten at a time in reverse chronological order.

---
title: Articles
filter:
- erb
- textile
---
h2. <%= h(@page.title) %>

<%
  articles = @pages.find(:all, :in_directory => "articles",
                         :sort_by => "mtime", :reverse => true)
  paginate(articles, 10) do |page|
%>
<%= page.render %>
<hr />
<% end %>

<%= link_to("Prev", @pager.prev) if @pager.prev? %>
<%= link_to("Next", @pager.next) if @pager.next? %>

In the example page above, the first step is get the collection of articles we are interested in the paginating. This is done using the @pages.find method to retrieve all the pages from the articles folder sorted in reverse order by modification time. When we have the collection of articles, we pass them to the paginate method along with the desired number of articles per page. The paginate method will pass each page in the articles collection to the supplied block of code, but for each ten pages passed to the block, a new webpage will be created.

Inside the block of code we simple render each page and separate the rendered pages using a horizontal rule. Finally, at the end of each page we generate Prev and Next links to supply navigation.

The @pager object provides a few other useful methods:

• number — the current page number
• number_of_pages — the total number of pages that will be generated
• first_item_number — the “item number” of the first item on this page
• last_item_number — the “item number” of the last item on this page
• first — a reference to the first pager (useful for link_to methods)
• last — a reference to the last pager (useful for link_to methods)
• page( number ) — a reference to the pager for page number (useful for link_to methods)

NOTE: the @pager is not instantiated until after the paginate method has been called. Therefore, references to other pages and item numbers cannot be made before the paginate method is called in the page.

2CodeRay

To include CodeRay syntax highlighting support in a page you need to have the coderay gem installed, and you need to include the CodeRay stylesheet in your layout. The following example shows a page that uses CodeRay syntax highlighting combined with Textile markup.

---
title:  CodeRay Example
filter:
- erb
- textile
--- 
h2. <%= h(@page.title) %>

This is the @render_page@ function from the Webby static website generation
system. It is used to render a page by applying the specified filters in
succession to the page contents.

<% coderay(:lang => "ruby", :line_numbers => "inline") do -%>
# call-seq:
#    render_page    => string
#
# Apply the desired filters to the page. The filters to apply are
# determined from the page's meta-data.
#
def render_page
  ary = []
  str = ::Webby::File.read(@page.path)

  @page.filter.to_a.each do |filter|
    str = self.send(filter + '_filter', str)
  end

  str
end
<% end -%>

There are more options that can be passed to the CodeRay syntax highlighter than those shown in the example above. Take a look at the RDoc documentation for the CodeRay Helper class for more information.