Class: PostRunner::PagingButtons

Inherits:
Object
  • Object
show all
Defined in:
lib/postrunner/PagingButtons.rb

Overview

A class to generate a set of forward/backward buttons for an HTML page. It can also include jump to first/last buttons.

Instance Method Summary collapse

Constructor Details

#initialize(page_urls, end_buttons = true) ⇒ PagingButtons

Create a new PagingButtons object.

Parameters:

  • page_urls (Array of String) —

    Sorted list of all possible pages

  • end_buttons (Boolean) (defaults to: true) —

    If true jump to first/last buttons are included



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# File 'lib/postrunner/PagingButtons.rb', line 25

def initialize(page_urls, end_buttons = true)
  if page_urls.empty?
    raise ArgumentError.new("'page_urls' must not be empty")
  end
  @pages = page_urls
  @current_page_index = 0
  @end_buttons = end_buttons
end

Instance Method Details

#current_page ⇒ Object

Return the URL of the current page



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# File 'lib/postrunner/PagingButtons.rb', line 35

def current_page
  @pages[@current_page_index]
end

#current_page=(page_url) ⇒ Object

Set the URL for the current page. It must be included in the URL set passed at creation time. The forward/backward links will be derived from the setting of the current page.

Parameters:

  • page_url (String) —

    URL of the page



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# File 'lib/postrunner/PagingButtons.rb', line 43

def current_page=(page_url)
  unless (@current_page_index = @pages.index(page_url))
    raise ArgumentError.new("URL #{page_url} is not a known page URL")
  end
end

#each ⇒ Object

Iterate over all buttons. A NavButtonDef object is passed to the block that contains the icon and URL for the button. If no URL is set, the button is inactive.



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# File 'lib/postrunner/PagingButtons.rb', line 52

def each
  %w( first back forward last ).each do |button_name|
    button = NavButtonDef.new
    button.icon = button_name + '.png'
    button.url =
      case button_name
      when 'first'
        @current_page_index == 0 || !@end_buttons ? nil : @pages.first
      when 'back'
        @current_page_index == 0 ? nil :
          @pages[@current_page_index - 1]
      when 'forward'
        @current_page_index == @pages.length - 1 ? nil :
          @pages[@current_page_index + 1]
      when 'last'
        @current_page_index == @pages.length - 1 ||
          !@end_buttons ? nil : @pages.last
      end

    yield(button)
  end
end