Class: Sakusei::HeadingWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/sakusei/heading_wrapper.rb

Overview

Wraps each h2/h3 heading and its immediately following content block in a <div style=“page-break-inside: avoid”> so that Chromium/Puppeteer keeps the heading glued to the content that follows it.

Operates on the markdown string after ERB and Vue processing so that Vue component output (already rendered to HTML) is treated as a normal block. Raw HTML in the markdown (html: true) passes through md-to-pdf untouched.

Constant Summary collapse

HEADING_PATTERN = 
/\A[ \t]*(##|###) /

Instance Method Summary collapse

Constructor Details

#initialize(content) ⇒ HeadingWrapper

Returns a new instance of HeadingWrapper.



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# File 'lib/sakusei/heading_wrapper.rb', line 14

def initialize(content)
  @content = content
end

Instance Method Details

#wrap ⇒ Object 



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# File 'lib/sakusei/heading_wrapper.rb', line 18

def wrap
  # Split on two-or-more blank lines to get top-level blocks.
  # Preserve the separator length so rejoining is faithful.
  blocks = @content.split(/(\n{2,})/)
  # split with a capture group gives us [block, sep, block, sep, ...]
  result = []
  i = 0
  while i < blocks.length
    block = blocks[i]
    sep   = blocks[i + 1] || "\n\n"

    if heading_block?(block)
      # Look ahead past the separator to the next content block
      next_block = blocks[i + 2]
      next_sep   = blocks[i + 3] || "\n\n"

      if next_block && !heading_block?(next_block)
        result << "<div style=\"page-break-inside: avoid\">\n\n#{block}#{sep}#{next_block}\n\n</div>"
        result << next_sep
        i += 4
        next
      end
    end

    result << block
    result << sep
    i += 2
  end

  result.join
end