Module: MapnikLegendary

Defined in:
lib/mapnik_legendary.rb,
lib/mapnik_legendary/part.rb,
lib/mapnik_legendary/tags.rb,
lib/mapnik_legendary/feature.rb,
lib/mapnik_legendary/version.rb,
lib/mapnik_legendary/geometry.rb,
lib/mapnik_legendary/docwriter.rb

Defined Under Namespace

Classes: Docwriter, Feature, Geometry, Part, Tags

Constant Summary collapse

DEFAULT_ZOOM = 
17
VERSION = 
'0.3.0'

Class Method Summary collapse

Class Method Details

.generate_legend(legend_file, map_file, options) ⇒ Object 



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# File 'lib/mapnik_legendary.rb', line 14

def self.generate_legend(legend_file, map_file, options)
  log = Logger.new(STDERR)

  legend = YAML.load(File.read(legend_file))

  if legend.key?('fonts_dir')
    Mapnik::FontEngine.register_fonts(legend['fonts_dir'])
  end

  map = Mapnik::Map.from_xml(File.read(map_file), false, File.dirname(map_file))
  map.width = legend['width']
  map.height = legend['height']
  map.srs = '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over'

  if legend.key?('background')
    map.background = Mapnik::Color.new(legend['background'])
  end

  layer_styles = []
  map.layers.each do |l|
    layer_styles.push(name: l.name,
                      style: l.styles.map { |s| s } # get them out of the collection
                      )
  end

  docs = Docwriter.new
  docs.image_width = legend['width']

  legend['features'].each_with_index do |feature, idx|
    # TODO: use a proper csv library rather than .join(",") !
    zoom = options.zoom || feature['zoom'] || DEFAULT_ZOOM
    feature = Feature.new(feature, zoom, map, legend['extra_tags'])
    map.zoom_to_box(feature.envelope)
    map.layers.clear

    feature.parts.each do |part|
      if part.layers.nil?
        log.warn "Can't find any layers defined for a part of #{feature.name}"
        next
      end
      part.layers.each do |layer_name|
        ls = layer_styles.select { |l| l[:name] == layer_name }
        if ls.empty?
          log.warn "Can't find #{layer_name} in the xml file"
          next
        else
          ls.each do |layer_style|
            l = Mapnik::Layer.new(layer_name, map.srs)
            datasource = Mapnik::Datasource.create(type: 'csv', inline: part.to_csv)
            l.datasource = datasource
            layer_style[:style].each do |style_name|
              l.styles << style_name
            end
            map.layers << l
          end
        end
      end
    end

    FileUtils.mkdir_p('output')
    # map.zoom_to_box(Mapnik::Envelope.new(0,0,1,1))
    id = feature.name || "legend-#{idx}"
    filename = File.join(Dir.pwd, 'output', "#{id}-#{zoom}.png")
    i = 0
    while File.exist?(filename) && !options.overwrite
      i += 1
      filename = File.join(Dir.pwd, 'output', "#{id}-#{zoom}-#{i}.png")
    end
    map.render_to_file(filename, 'png256:t=2')
    docs.add File.basename(filename), feature.description
  end

  f = File.open(File.join(Dir.pwd, 'output', 'docs.html'), 'w')
  f.write(docs.to_html)
  f.close

  title = legend.key?('title') ? legend['title'] : 'Legend'
  docs.to_pdf(File.join(Dir.pwd, 'output', 'legend.pdf'), title)
end