Class: DotHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/dothtml/dot_helper.rb

Constant Summary collapse

GRAPH_REGEX = 
/\b(?:di)?graph\b[^\[]*\{/mi
DOT_REGEX = 
/->/

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(svg_contents) ⇒ DotHelper

Returns a new instance of DotHelper.



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# File 'lib/dothtml/dot_helper.rb', line 10

def initialize(svg_contents)
  @svg_contents = svg_contents
end

Class Method Details

.detect_language(contents, language = nil) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 114

def self.detect_language(contents, language = nil)
  language || ((contents =~ DOT_REGEX) ? 'dot' : 'neato')
end

.enhance(contents, language) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 118

def self.enhance(contents, language)
  if contents =~ GRAPH_REGEX
    contents
  elsif language == 'dot'
    <<-GRAPH
    digraph {
      #{contents}
    }
    GRAPH
  else
    <<-GRAPH
    graph {
      #{contents}
    }
    GRAPH
  end
end

.from_dot(contents, language = 'dot') ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 136

def self.from_dot(contents, language = 'dot')
  language = detect_language(contents, language)
  contents = enhance(contents, language)
  new(svg_from_dot(contents, language))
end

.from_dotfile(filename) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 110

def self.from_dotfile(filename)
  new(svg_from_dot(File.read(filename)))
end

.svg_from_dot(contents, language = 'dot') ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 142

def self.svg_from_dot(contents, language = 'dot')
  Open3.popen3("#{language} -Tsvg") do |stdin, stdout, stderr|
    stdout.binmode
    stdin.print contents
    stdin.close

    err = stderr.read
    if !err.nil? && !err.strip.empty?
      raise "Error from graphviz:\n#{err}"
    end

    stdout.read.tap { |str| str.force_encoding 'UTF-8' }
  end
end

Instance Method Details

#descriptions? ⇒ Boolean

return true if the nodes have descripions?

This will create a div box where descriptions can be displayed

Returns:

  • (Boolean) 


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# File 'lib/dothtml/dot_helper.rb', line 37

def descriptions?
  #dom.css("")
end

#dom ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 18

def dom
  @dom ||= parse_dom(@svg_contents)
end

#embed_images ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 87

def embed_images
  node.children.before(images)
  self
end

#extract_id_class(old_id) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 79

def extract_id_class(old_id)
  if old_id =~ /(.*?) ?class=["']?(.*?)['"]?$/
    [$1, $2]
  else
    [old_id]
  end
end

#extractChoices ⇒ Object

return the list of choices provided for a user

these choices are displayed to modify the data on the page

this will add a body css class and trigger a data event for d3js



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# File 'lib/dothtml/dot_helper.rb', line 29

def extractChoices
end

#extractTitle ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 41

def extractTitle
  dom.css("title").first.content()
end

#images ⇒ Object

Embed svg image links directly into the document

this currently has too many issues working on making this more friendly assume unique list of filenames



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# File 'lib/dothtml/dot_helper.rb', line 50

def images
  embedded_images = Set.new

  defs = dom.create_element("def")

  # assuming the images are the correct size, declare their size
  dom.css("image").each do |img|
    file_name = img.attributes["href"].value
    id = file_name.split(".").first.split("/").last
    if file_name =~ /\.svg$/ && ! embedded_images.include?(file_name)
      src = parse_dom(File.read(file_name)).at("svg")
      g = dom.create_element("g", id: id,
        width: src["width"], height: src["height"])
      defs.add_child(g)
      src.children.each do |child|
        g.add_child(child.clone)
      end
      embedded_images << file_name
    end

    img.name="use"
    img.attributes["href"].value="##{id}"
    #img.attributes["width"].remove
    #img.attributes["height"].remove
    #img.attributes["preserveAspectRatio"].remove
  end
  defs
end

#node ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 97

def node
  dom.at("svg")
end

#parse_dom(contents) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 14

def parse_dom(contents)
  Nokogiri::XML.parse(contents)
end

#remove_comments ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 92

def remove_comments
  dom.xpath('//comment()').each { |comment| comment.remove }
  self
end

#to_xml ⇒ Object

uses a fragment to remove extra xml declarations



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# File 'lib/dothtml/dot_helper.rb', line 102

def to_xml
  node.to_xml
end

#write(file_name, template_name, locals) ⇒ Object 



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# File 'lib/dothtml/dot_helper.rb', line 106

def write(file_name, template_name, locals)
  File.write(file_name, Tilt.new(template_name).render(binding, locals))
end