Prawn PDF中的页眉和页脚

Question

我已经通读了有关Prawn的所有相关帖子，但没有发现(即使在Prawn自己的文档中)也没有提到页眉和页脚。

然而，我确实在Prawnto自己的网站上看到了一个关于页眉和页脚的演示。我复制了该演示的整个源代码，只是为了看看它是否工作，但有一个未定义的方法"header“的错误被投诉。我是不是可以理解为，最近在gem中，对虾去掉了页眉和页脚，或者我还需要先做些什么才能使用页眉和页脚？

演示页面：http://cracklabs.com/prawnto/code/prawn_demos/source/text/flowing_text_with_header_and_footer

代码中值得关注的部分：

Prawn::Document.generate("flow_with_headers_and_footers.pdf")  do

  header margin_box.top_left do 
      text "Here's My Fancy Header", :size => 25, :align => :center   
  end   

  text "hello world!"
end

说到标题，以防万一，我指的是通常出现在文档每页角落的单词片段。就像账单页上的账号一样。

谢谢!

Answer 1

@GrantSayer thx作为示例，但这将只允许您显示当前页码，而不是总页数。

您还可以对页脚使用number_pages函数：

Prawn::Document.generate("page_with_numbering.pdf") do
  text "Hai"
  start_new_page
  text "bai"
  start_new_page
  text "-- Hai again"
  number_pages "<page> in a total of <total>", [bounds.right - 50, 0]
end

然而，在我的例子中，我还需要格式化/样式并将页码右对齐，以匹配公司的风格指南。我使用go_to_page(k)创建了我自己的页眉和页脚函数，它在创建所有页面之后将页眉和页脚添加到每个页面中。这为我提供了样式选项和总页数：

Prawn::Document.generate("footer_example.pdf", :skip_page_creation => true) do
  10.times do
    start_new_page
    text "Some filler text for the page"
  end

  # footer
  page_count.times do |i|
    go_to_page(i+1)
    lazy_bounding_box([bounds.right-50, bounds.bottom + 25], :width => 50) {
      text "#{i+1} / #{page_count}"
    }.draw
  end
end

Answer 2

您引用的示例，来自prawnto插件，使用的是较旧版本的对虾。

因为我还需要页眉和页脚，所以我对此进行了更深入的研究。似乎对虾版本有页眉和页脚方法，这些方法是使用惰性边界框实现的。(通过查看github上的代码找到)

在新的对虾版本中，你可以使用中继器做同样的事情。

下面是使用新版本重写的完整示例：

require "#{File.dirname(__FILE__)}/../example_helper.rb"

Prawn::Document.generate("test.pdf")  do

   repeat :all do
    # header
    bounding_box [bounds.left, bounds.top], :width  => bounds.width do
        font "Helvetica"
        text "Here's My Fancy Header", :align => :center, :size => 25
        stroke_horizontal_rule
    end

    # footer
    bounding_box [bounds.left, bounds.bottom + 25], :width  => bounds.width do
        font "Helvetica"
        stroke_horizontal_rule
        move_down(5)
        text "And here's a sexy footer", :size => 16
    end
  end

  bounding_box([bounds.left, bounds.top - 50], :width  => bounds.width, :height => bounds.height - 100) do                 
   text "this is some flowing text " * 200    

   move_down(20)

   font "#{Prawn::BASEDIR}/data/fonts/DejaVuSans.ttf"
   table [["ὕαλον ϕαγεῖν",    "baaar",             "1" ],
          ["This is","a sample",          "2" ],
          ["Table",  "dont\ncha\nknow?",  "3" ],
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules\nwith an iron fist", "x" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],   
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ],  
          [ "It",    "Rules",             "4" ],     
          [ "It",    "Rules",             "4" ]],     

     :font_size          => 24, 
     :horizontal_padding => 10,
     :vertical_padding   => 3,
     :border_width       => 2,
     :position           => :center,
     :headers            => ["Column A","Column B","#"]

  end
end

您可以查看repeat的文档页面中的其他选项，这些选项允许您准确地指定您想要中继器的位置。

Answer 3

与最新版本的Prawn稍有不同，您必须传递一个散列

Prawn::Document.generate("page_with_numbering.pdf") do
  text "Hai"
  start_new_page
  text "bai"
  start_new_page
  text "-- Hai again"
  number_pages "<page> in a total of <total>", { :start_count_at => 0, :page_filter => :all, :at => [bounds.right - 50, 0], :align => :right, :size => 14 }
end