Class: Mathematical::Render

Inherits:
Object
  • Object
show all
Defined in:
lib/mathematical/render.rb

Constant Summary collapse

DEFAULT_OPTS = 
{
  :ppi => 72.0,
  :zoom => 1.0
}

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Render

Returns a new instance of Render.

Raises:

  • (TypeError) 


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# File 'lib/mathematical/render.rb', line 12

def initialize(opts = {})
  raise(TypeError, "opts must be a hash!") unless opts.is_a? Hash

  @config = DEFAULT_OPTS.merge(opts)
  begin
    @processer = Mathematical::Process.new(@config)
  rescue TypeError => e # some error in the C code
    raise
  end

end

Instance Method Details

#named_type(type) ⇒ Object 



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# File 'lib/mathematical/render.rb', line 71

def named_type(type)
  "#{type.to_s}-math"
end

#render(text) ⇒ Object

Raises:

  • (TypeError) 


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# File 'lib/mathematical/render.rb', line 24

def render(text)
  raise(TypeError, "text must be a string!") unless text.is_a? String

  # TODO: figure out how to write svgs without the tempfile
  tempfile = Tempfile.new('foo')
  text.gsub(Mathematical::Parser::REGEX) do |maths|
    if maths =~ /^\$(?!\$)/
      just_maths = maths[1..-2]
      type = :inline
    elsif maths =~ /^\\\((?!\\\[)/
      just_maths = maths[2..-4]
      type = :inline
    elsif maths =~ /^\\\[(?!\\\[)/
      just_maths = maths[2..-4]
      type = :display
    elsif maths =~ /^\\begin(?!\\begin)/
      just_maths = maths[16..-15]
      type = :display
    end

    # this is the format itex2MML expects
    if type == :inline
      just_maths = "$#{just_maths}$"
    else
      just_maths = "$$#{just_maths}$$"
    end

    begin
      status = @processer.process(just_maths, tempfile.path)
      raise RuntimeError unless status == 0
      svg_content = File.open(tempfile.path, 'r') { |image_file| image_file.read }
      svg_content = svg_content.lines.to_a[1..-1].join
    rescue RuntimeError => e # an error in the C code, probably a bad TeX parse
      $stderr.puts e.message
      return just_maths
    end

    "<img class=\"#{named_type(type)}\" data-math-type=\"#{named_type(type)}\" src=\"data:image/svg+xml;base64,#{svg_to_base64(svg_content)}\"/>"
  end
  tempfile.close
  tempfile.unlink
end

#svg_to_base64(contents) ⇒ Object 



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# File 'lib/mathematical/render.rb', line 67

def svg_to_base64(contents)
  Base64.strict_encode64(contents)
end