ioquatix/graphviz

# Copyright, 2014, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require_relative "graphviz/version"
require_relative "graphviz/graph"

require 'process/pipeline'

module Graphviz
    # Outputs the graph using the +dot+ executable.
    # @return [String] any data generated by the command unless an output path is specified.
    #
    # @option options [String] :format ('pdf') The output format (e.g. pdf).
    # @option options [String] :path The output path, if not specified data is returned.
    # @option options [String] :dot ('dot') The +dot+ executable to use.
    def self.output(graph, path: nil, format: 'pdf', dot: 'dot')
        output_format = format
        
        if path
            # Grab the output format from the file name:
            if path =~ /\.(.*?)$/
                output_format ||= $1
            end
        end
        
        output, input = IO.pipe
        pipeline = Process::Pipeline.(dot, "-T#{output_format}")
        
        writer = Thread.new do
            graph.dump_graph(input)
            
            input.close
        end
        
        if path
            pipeline.write(path, input: output)
        else
            return pipeline.read(input: output)
        end
    ensure
        writer.join
    end
end