我已经阅读了 Prawn 上的所有相关帖子,但没有发现(即使在 Prawn 自己的文档中)提到页眉和页脚。
不过,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有效,但有人抱怨未定义方法“标头”的错误。我是否可以理解,Prawn 最近在 gem 中取出了页眉和页脚,或者我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
关注代码部分:
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
为了以防万一,我所说的标题是指通常出现在文档每页角落的单词片段。就像您的账单页面中的帐号一样。
谢谢!
您所引用的示例来自 prawnto 插件,使用的是旧版本的 prawn。
因为我还需要页眉和页脚,所以我对此进行了更多研究。那个版本的虾似乎有页眉和页脚方法,它们是使用惰性边界框实现的。 (查看github上的代码找到的)
在新的虾版本中你可以使用中继器做同样的事情。
这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 的文档页面以了解其他选项,这些选项允许您准确指定中继器的位置。
@GrantSayer 谢谢这个例子,但这只会让你显示当前页码,而不是总页数。
您还可以使用页脚的 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
但是,就我而言,我还需要格式化/样式并右对齐页码以匹配公司样式指南。我使用 go_to_page(k) 创建自己的页眉和页脚函数,在创建所有页面后将页眉和页脚添加到每个页面。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
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
bounding_box
在文档边距下方创建
bounds.bottom
。
require 'prawn'
file_name = 'hello.pdf'
random_table = (0..50).map{|i|[*('a'..'z')]} # generate a 2D array for example (~2 pages)
Prawn::Document::generate(file_name) do |pdf|
pdf.table random_table
pdf.page_count.times do |i|
pdf.bounding_box([pdf.bounds.left, pdf.bounds.bottom], :width => pdf.bounds.width, :height => 30) {
# for each page, count the page number and write it
pdf.go_to_page i+1
pdf.move_down 5 # move below the document margin
pdf.text "#{i+1}/#{pdf.page_count}", :align => :center # write the page number and the total page count
}
end
end
它应该是这样的,您可以看到页脚位于边距底部之外:
希望对某人有帮助
开始编辑
这适用于> = 0.12 的虾
结束编辑
这是我使用重复、画布和单元格的解决方案。本质上,我是在每个页面的绝对顶部和底部绘制边界框。我使用单元格来更好地控制它的样式。希望这会对某人有所帮助。 (我使用了稍微烦人的颜色来更好地说明如何控制页眉和页脚的样式)
Prawn::Document.generate("headers_and_footers_with_background.pdf") do
repeat :all do
# header
canvas do
bounding_box([bounds.left, bounds.top], :width => bounds.width) do
cell :content => 'Header',
:background_color => 'EEEEEE',
:width => bounds.width,
:height => 50,
:align => :center,
:text_color => "001B76",
:borders => [:bottom],
:border_width => 2,
:border_color => '00FF00',
:padding => 12
end
end
# footer
canvas do
bounding_box [bounds.left, bounds.bottom + 50], :width => bounds.width do
cell :content => 'Footer',
:background_color => '333333',
:width => bounds.width,
:height => 50,
:align => :center,
:text_color => "FFFFFF",
:borders => [:top],
:border_width => 2,
:border_color => 'FF0000',
:padding => 12
end
end
end
# body
bounding_box([bounds.left, bounds.top - 25], :width => bounds.width, :height => bounds.height - 50) do
100.times do
text "Some filler text for the page"
end
end
end
bounding_box
创建自定义页脚内容时的问题...它仍然在边距范围内呈现。我一直在寻找可以将内容
与number_pages
一起写在边距区域
中的东西。(因为页脚通常设置在底部边距区域)...但似乎没有。所以,我使用
text_box
并将坐标放置在我的主边界框之外,如下所示:
repeat :all do
text_box "My custom footer", size: 7, align: :center, :at => [bounds.left, bounds.bottom], :height => 100, :width => bounds.width
end
请注意
repeat :all
会将此页脚文本呈现到每个页面。
Prawn::Document::LazyBoundingBox
方法。基本上,这允许您定义一个边界框,该边界框仅在您调用它时才会呈现。所以通常的
pseudo-code
步骤是
file = "lazy_bounding_boxes.pdf"
Prawn::Document.generate(file, :skip_page_creation => true) do
point = [bounds.right-50, bounds.bottom + 25]
page_counter = lazy_bounding_box(point, :width => 50) do
text "Page: #{page_count}"
end
10.times do
start_new_page
text "Some filler text for the page"
page_counter.draw
end
end
这将为您在每个新页面上提供页数文本输出。理想的情况是,如果这可以应用于页面模板的设置中,并且无需手动调用来渲染元素,即可重复使用该页面模板。与文本流相结合,这将提供页眉和页脚的传统解决方案。
module PdfGenerator
class Base
HEADER_HEIGHT = 30
FOOTER_HEIGHT = 30
MARGIN_FACTOR = 1.2
def initialize(_ = nil)
@pdf = Prawn::Document.new
end
def apply_header(header = "Custom Builder Select")
@pdf.page_count.times do |i|
next if i == 0
@pdf.go_to_page(i + 1)
@pdf.bounding_box([@pdf.bounds.left, @pdf.bounds.top], width: @pdf.bounds.width, height: HEADER_HEIGHT) do
@pdf.fill_color "44403c"
@pdf.fill_rectangle [0, @pdf.bounds.top], @pdf.bounds.width, HEADER_HEIGHT
@pdf.fill_color "FFFFFF"
@pdf.move_down HEADER_HEIGHT / 2 - 6
@pdf.text header, align: :center, size: 12
end
end
end
def apply_footer
@pdf.page_count.times do |i|
next if i == 0
@pdf.go_to_page(i + 1)
@pdf.bounding_box([@pdf.bounds.left, @pdf.bounds.bottom + FOOTER_HEIGHT], width: @pdf.bounds.width, height: FOOTER_HEIGHT) do
@pdf.fill_color "44403c"
@pdf.fill_rectangle [0, @pdf.bounds.top], @pdf.bounds.width, FOOTER_HEIGHT
@pdf.fill_color "FFFFFF"
@pdf.move_down FOOTER_HEIGHT / 2 - 5
@pdf.text "#{i + 1} / #{@pdf.page_count}", align: :center, size: 10
end
end
end
def apply_body
@pdf.bounding_box(
[@pdf.bounds.left, @pdf.bounds.top - HEADER_HEIGHT * MARGIN_FACTOR],
width: @pdf.bounds.width,
height: @pdf.bounds.height - (HEADER_HEIGHT + FOOTER_HEIGHT) * MARGIN_FACTOR
) do
yield if block_given?
end
end
def render
@pdf.render
end
end
end
然后,当我想在特定类型的 PDF 生成器中使用它时,我会这样做:
module PdfGenerator
class YourPdfClass < Base
def initialize(thing)
super
@thing = thing
end
def render
cover_page # A method for your cover page
apply_body do
things_pages # A method where you build the content of this things pages
end
apply_header(@thing.name)
apply_footer
@pdf.render
end
end
end
这里的主要区别是,我存储了页眉和页脚的尺寸,以便我可以一致地间隔这些尺寸,然后页面的主体位于由这些尺寸定义的框中。如果出于某种原因我想要一个更高的标题,我可以更改该常量,它将调整我的标题、正文开始的点以及正文结束/页脚开始的点。边距因素是在我的身体和页眉/页脚之间留下一点填充。如果您愿意,您还可以将字体大小设置为常数来计算文本的垂直居中。