Module: Slideshow::TextFilter

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# File 'lib/slideshow/filters/text_filter.rb', line 97

def comments_percent_style( content )    

# skip filter for pandoc
# - pandoc uses % for its own markdown extension

return content  if @markup_type == :markdown && @markdown_libs.first == 'pandoc-ruby'
  
  # remove comments
  # % comments
  # %begin multiline comment
  # %end multiline comment

  # track statistics
  comments_multi  = 0
  comments_single = 0
  comments_end    = 0

  # remove multi-line comments
  content.gsub!(/^%(begin|comment|comments).*?%end/m) do |match|
    comments_multi += 1
    ""
  end
  
   # remove everyting starting w/ %end (note, can only be once in file) 
  content.sub!(/^%end.*/m) do |match|
    comments_end += 1
    ""
  end

  # hack/note: 
  #  note multi-line erb expressions/stmts might cause trouble
  #  
  #  %> gets escaped as special case (not treated as comment)
  # <%
  #   whatever
  # %> <!-- trouble here; would get removed as comment!
  #  todo: issue warning?
  
  # remove single-line comments    
  content.gsub!(/(^%$)|(^%[^>].*)/ ) do |match|
    comments_single += 1
    ""
  end
  
  puts "  Removing %-comments (#{comments_single} lines, " +
     "#{comments_multi} begin/end-blocks, #{comments_end} end-blocks)..."
  
  content    
end

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# File 'lib/slideshow/filters/text_filter.rb', line 9

def directives_bang_style_to_percent_style( content )

  # for compatibility allow !SLIDE/!STYLE as an alternative to %slide/%style-directive
  
  bang_count = 0

  # get unparsed helpers e.g. SLIDE|STYLE  
  unparsed = config.helper_unparsed.map { |item| item.upcase }.join( '|' )                                                                   
  
  content.gsub!(/^!(#{unparsed})(.*)$/) do |match|
    bang_count += 1
    "<%= #{$1.downcase} '#{$2 ? $2 : ''}' %>"
  end

  puts "  Patching !-directives (#{bang_count} #{config.helper_unparsed.join('/')}-directives)..."

  content
end

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# File 'lib/slideshow/filters/text_filter.rb', line 28

def directives_percent_style( content )

  # skip filter for pandoc
  # - pandoc uses % for its own markdown extension
  # - don't process % pass it along/through to pandoc

  return content  if @markup_type == :markdown && @markdown_libs.first == 'pandoc-ruby'
    
    
  directive_unparsed  = 0
  directive_expr      = 0
  directive_block_beg = 0
  directive_block_end = 0

  # process directives (plus skip %begin/%end comment-blocks)

  inside_block  = 0
  inside_helper = false
  
  content2 = ""
  
  content.each_line do |line|
    if line =~ /^%([a-zA-Z][a-zA-Z0-9_]*)(.*)/
      directive = $1.downcase
      params    = $2

      logger.debug "processing %-directive: #{directive}"

      # slide, style
      if config.helper_unparsed.include?( directive )
        directive_unparsed += 1
        content2 << "<%= #{directive} '#{params ? params : ''}' %>"
      elsif config.helper_exprs.include?( directive )
        directive_expr += 1
        content2 << "<%= #{directive} #{params ? erb_simple_params(directive,params) : ''} %>"        
      elsif inside_helper && directive == 'end'
        inside_helper = false
        directive_block_end += 1
        content2 << "%>"        
      elsif inside_block > 0 && directive == 'end'
        inside_block -= 1
        directive_block_end += 1
        content2 << "<% end %>"
      elsif [ 'comment', 'comments', 'begin', 'end' ].include?( directive )  # skip begin/end comment blocks
        content2 << line
      elsif [ 'helper', 'helpers' ].include?( directive )
        inside_helper = true
        directive_block_beg += 1
        content2 << "<%"
      else
        inside_block += 1
        directive_block_beg += 1
        content2 << "<% #{directive} #{params ? erb_simple_params(directive,params) : ''} do %>"
      end
    else
      content2 << line
    end
  end  
    
  puts "  Preparing %-directives (" +
      "#{directive_unparsed} #{config.helper_unparsed.join('/')} directives, " +
      "#{directive_expr} #{config.helper_exprs.join('/')} expr-directives, " +
      "#{directive_block_beg}/#{directive_block_end} block-directives)..."

  content2
end

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# File 'lib/slideshow/filters/text_filter.rb', line 175

def erb( content )
  puts "  Running embedded Ruby (erb) code/helpers..."
  
  content =  ERB.new( content ).result( binding() )
  content
end

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# File 'lib/slideshow/filters/text_filter.rb', line 233

def erb_django_simple_params( code )
  
  # split into method/directive and parms plus convert params
  code.sub!( /^[ \t]([\w.]+)(.*)/ ) do |match|
    directive = $1
    params    = $2
    
    "#{directive} #{params ? erb_simple_params(directive,params) : ''}"     
  end
  
  code
end

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# File 'lib/slideshow/filters/text_filter.rb', line 246

def erb_django_style( content )

  # replace expressions (support for single lines only)
  #  {{ expr }}  ->  <%= expr %>
  #  {% stmt %}  ->  <%  stmt %>   !! add in do if missing (for convenience)
  #
  # use use {{{ or {{{{ to escape expr back to literal value
  # and use {%% %} to escape stmts

  erb_expr = 0
  erb_stmt_beg = 0
  erb_stmt_end = 0

  content.gsub!( /(\{{2,4})([^{}\n]+?)(\}{2,4})/ ) do |match|
    escaped = ($1.length > 2)
    if escaped
      "{{#{$2}}}"
    else
      erb_expr += 1
      "<%= #{erb_django_simple_params($2)} %>"        
    end
  end

  content.gsub!( /(\{%{1,2})([ \t]*end[ \t]*)%\}/ ) do |match|
    escaped = ($1.length > 2)
    if escaped
      "{%#{$2}%}"
    else
      erb_stmt_end += 1
      "<% end %>"
    end
  end

  content.gsub!( /(\{%{1,2})([^%\n]+?)%\}/ ) do |match|
    escaped = ($1.length > 2)
    if escaped
      "{%#{$2}%}"
    else
      erb_stmt_beg += 1
      "<% #{erb_django_simple_params($2)} do %>"
    end
  end

  puts "  Patching embedded Ruby (erb) code Django-style (#{erb_expr} {{-expressions," +
     " #{erb_stmt_beg}/#{erb_stmt_end} {%-statements)..."
       
  content        
end

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# File 'lib/slideshow/filters/text_filter.rb', line 155

def erb_rename_helper_hack( content )
  # note: include is a ruby keyword; rename to s9_include so we can use it 
  
  rename_counter = 0
  
  # turn renames into something like:
  #   include|class   etc.
  renames = config.helper_renames.join( '|' )
  
  content.gsub!( /<%=[ \t]*(#{renames})/ ) do |match|
    rename_counter += 1
    "<%= s9_#{$1}" 
  end

  puts "  Patching embedded Ruby (erb) code for aliases (#{rename_counter} #{config.helper_renames.join('/')}-aliases)..."

  content
end

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# File 'lib/slideshow/filters/text_filter.rb', line 182

def erb_simple_params( method, params )
  
  # replace params to support html like attributes e.g.
  #  plus add comma separator
  #
  #  class=part       -> :class => 'part'   
  #  3rd/tutorial     -> '3rd/tutorial'
  #  :css             -> :css
  
  return params   if params.nil? || params.strip.empty?

  params.strip!    
  ## todo: add check for " ??
  if params.include?( '=>' )
    puts "** warning: skipping patching of params for helper '#{method}'; already includes '=>':"
    puts "  #{params}"
    
    return params
  end
  
  before = params.clone
  
  # 1) string-ify values and keys (that is, wrap in '')
  #  plus separate w/ commas
  params.gsub!( /([:a-zA-Z0-9#][\w\/\-\.#()]*)|('[^'\n]*')/) do |match|
    symbol = ( Regexp.last_match( 0 )[0,1] == ':' )
    quoted = ( Regexp.last_match( 0 )[0,1] == "'" )
    if symbol || quoted  # return symbols or quoted string as is
      "#{Regexp.last_match( 0 )},"
    else
      "'#{Regexp.last_match( 0 )}',"
    end
  end
      
  # 2) symbol-ize hash keys
  #    change = to =>
  #    remove comma for key/value pairs
  params.gsub!( /'(\w+)',[ \t]*=/ ) do |match|
    ":#{$1}=>"
  end
  
  # 3) remove trailing comma
  params.sub!( /[ \t]*,[ \t]*$/, '' ) 
   
  puts "    Patching params for helper '#{method}' from '#{before}' to:"
  puts "      #{params}"  
     
  params    
end

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# File 'lib/slideshow/filters/text_filter.rb', line 147

def skip_end_directive( content )
  # codex-style __SKIP__, __END__ directive
  # ruby note: .*? is non-greedy (shortest-possible) regex match
  content.gsub!(/__SKIP__.*?__END__/m, '')
  content.sub!(/__END__.*/m, '')
  content
end