karmi · November 3, 2015 05:02
diff --git a/.gitignore b/.gitignore
 .DS_Store
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <html>
 <head>
  <title>Life Expectancy : 1960 &mdash; 2011</title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <script src="http://mbostock.github.com/d3/d3.v2.min.js?2.8.1"></script>
  <style>
    /* Styling for the page */
    body { font: normal 10px Helvetica, sans-serif; margin: 2em; }
    /* Styling for the chart */
    #chart { position: relative; padding-top: 2.5em; }
    select#select_country { position: absolute; top: 0; left: 30px; }
    line.rule { stroke: #eee; stroke-width: 1; shape-rendering: crispEdges; }
    text.tick { fill: #ccc; text-anchor: end; }
    rect.bar { stroke: white; border-width: 1px; fill: #7BC8FB; }
    rect.bar.missing { fill: #ccc; }
    text.label { fill: white; text-anchor: middle; }
    text.label.missing { font-size: 8px; }
    text.legend { fill: #7BC8FB; text-anchor: middle; rotate: 45; }
    .over rect.bar { fill: black; }
    .over text.legend { fill: black; }
    .mean path { stroke: #000; stroke-dasharray: 2,2; stroke-width: 1px; fill: none; }
  </style>
 </head>
 <body>
  <div id="chart"></div>
 </body>

 <script>
  var BarChart = function(url) {
        // Configuration
        //
    var config = {
          width:  900 - 20,
          height: 100,
          margin: 20
        },

        // Chart
        //
        chart = d3.select("#chart").append("svg")
                   .attr("width",  config.width)
                   // Make room for the bottom labels
                   .attr("height", config.height + config.margin*2)
                  .append("g")
                   // Make room for left-side tick labels and top rule line
                   .attr("transform", "translate(" + 10 + "," + 10 + ")"),

        // Country select
        //
        select = d3.select("#chart")
          .append("select")
          .attr("id", "select_country")
          .attr("accesskey", "c")
          .on("change", function(e) { return __draw(this.value); }),

        // CSV data
        //
        csv  = null,

        // Display the chart for a specific country (load data if missing)
        //
        display = function(country) {
          if ( ! csv ) {
            return __load(url, function() { return __draw(country); })
          } else {
            return __draw(country);
          }
        },

        // Convert a String to DOM ID friendly format
        //
        __parameterize = function(s) {
          return s.toLowerCase().replace(/[^a-z]/g, "-")
        },

        // Load the CSV data from external source
        //
        __load = function(url, callback) {
          d3.csv(url, function(data) {
            // Assign data from CSV
            csv = data;

            // Select
            var countries = select
              .selectAll("option")
              .data( csv.map( function(d) { return d["Country Name"]; } ) )
              .enter()
               .append("option")
               .attr("value", function(d) { return d; })
               .attr("id",    function(d) { return "option-"+__parameterize(d); })
               .text(function(d) { return d; });

            // Perform the callback
            callback();
          });
        },

        // Draw the chart
        //
        __draw = function(country) {
          // console.log("CSV:",  csv);

                       // Select a specific country
          var data   = csv.filter( function(d) { return d["Country Name"] == country; } ),

                       // Filter out keys (years)
              legend = d3.keys(data[0])
                         .filter( function(d) { return d.match(/^\d/); } ),

                       // Filter out values and convert them to numbers
              values = d3.entries(data[0])
                         .filter( function(d) { return d.key.match(/^\d/); } )
                         .map( function(d) { return d.value; } )
                         .map( function(d) { return parseFloat(d) || null; } );

          console.debug("Legend:", legend);
          console.debug("Values:", values);

          // Select selected country
          d3.selectAll("#select_country option").attr("selected", null);
          d3.select("#option-"+__parameterize(country)).attr("selected", true);

          // 1) Scales
          var x = d3.scale.ordinal()
                    .domain( values.map(function(d,i) { return i; }) )
                    .rangeRoundBands([0, config.width], 0.1);

          var y = d3.scale.linear()
                    .domain([0, 100])
                    .range([0, config.height]);

          // 2) Ticks
          var tick = chart.selectAll("g.tick").data(y.ticks(5))
                       .enter()
                      .append("g")
                       .attr("class", "tick");

          tick
           .append("line")
            .classed("rule", true)
            .attr("x1", 22)
            .attr("x2", config.width)
            .attr("y1", y)
            .attr("y2", y);

          tick
           .append("text")
            .classed("tick", true)
            .attr("x", 18)
            .attr("y", function(d) { return config.height - y(d); })
            .attr("dy", 3)
            .text(function(d) { return (d) ? d : null; });

          // 3) Bars
          var bar = chart.selectAll("g.bar").data(values);

          var group = bar.enter()
                        .append("g")
                        .attr("class", "bar")
          group
            .append("rect")
             .classed("bar", true)
             .attr("height", 0)
             .attr("y",      config.height);
          group
            .append("text")
             .classed("label", true);
          group
            .append("text")
             .classed("legend", true)

          bar
           .exit()
            .remove();

          bar
           .select("rect.bar")
            .classed("missing", function(d,i) { return !d; })
            .attr("width",  x.rangeBand())
            .attr("x",      function(d,i) { return x(i); })
           .transition()
             .duration(500)
            .attr("height", function(d,i) { return y(d) || 15; })
            .attr("y",      function(d,i) { return d ? config.height - y(d) : config.height - 15; })

          bar
            .on("mouseover", function(d,i) { return d3.select(this).classed("over", true);  })
            .on("mouseout",  function(d,i) { return d3.select(this).classed("over", false); });

          // 4) Labels (values)
          bar
           .select("text.label")
            .classed("missing", function(d,i) { return !d; })
            .attr("x",      function(d,i) { return x(i) + Math.round(x.rangeBand()/2); })
            .attr("y",      config.height - 5)
            .text(          function(d,i) { return d ? Math.round(d) : "n/a" ; });

          // 5) Legend (years)
          bar
           .select("text.legend")
            .data(legend)
            .classed("legend", true)
            .attr("x",      function(d,i) { return x(i) + Math.round(x.rangeBand()/2); })
            .attr("y",      config.height + 10)
            .attr("transform", function(d,i) { return "rotate(45 " + x(i) + ", " + (config.height + 15) + ")"; })
            .text(function(d,i) { return d; });


          // Display the "mean" line across the whole dataset
          //
          if ( d3.select(".mean") < 1 ) {
            var means = csv
              .reduce(function(previous, current, index) {
                // 1) Extract years
                //
                var years = d3.keys(current).filter( function(d) { return d.match(/^\d/); } );

                // 2) For each year, extract all values
                //    (based on the column position; year 1960 has the same position across the dataset)
                //
                years.forEach(function(d,i) {
                  if ( ! previous[i] )        { previous[i] = [] };

                  previous[i].push(parseFloat(current[d]))
                });

                return previous;
              }, [])

              .reduce(function(previous, current, index) {
                // 3) Compute mean for each year
                //
                var mean = d3.mean(current);
                previous.push(mean)
                return previous;
              }, [])

              // 4) Remove null values
              //
              .filter(function(d) { return d; });

              // 5) Duplicate last value for proper line display
              //
              means.push(d3.last(means));

              // Log the values to console
              //
              console.log("Mean values:", means);

            // Draw line based on means
            //
            var line = chart.selectAll("g.mean").data([means])
            line
              .enter()
               .append("g")
               .classed("mean", true)
               .append("path")
               .attr("opacity", 0)
              .transition()
                .delay(500)
                .duration(500)
               .attr("opacity", 0.6)
               .attr("d", d3.svg.line()
                 .interpolate("step-before")
                 .x(function(d,i) { return x(i); })
                 .y(function(d,i) { return config.height - Math.round(y(d)); })
               );
          };

          return chart;
        };

    return {
      display: display
    };
  };

  var chart = new BarChart("life-expectancy-full.csv");

  chart.display(top.location.search.replace(/\?/, "") || "Czech Republic");

 </script>

 </html>
diff --git a/life-expectancy-czech-republic.json b/life-expectancy-czech-republic.json
 var data = [70.3487804878,70.5126829268,69.7868292683,70.3043902439,70.4595121951,70.1631707317,70.3848780488,70.2641463415,69.8407317073,69.3670731707,69.4402439024,69.6770731707,70.1765853659,70.0226829268,70.0865853659,70.4146341463,70.5326829268,70.5734146341,70.643902439,70.7495121951,70.2780487805,70.722195122,70.807804878,70.5914634146,70.8375609756,71.0463414634,70.9973170732,71.4456097561,71.6414634146,71.6756097561,71.383902439,71.8982926829,72.2717073171,72.767804878,72.9726829268,73.0748780488,73.7146341463,73.8248780488,74.5146341463,74.6682926829,74.9682926829,75.1731707317,75.2219512195,75.1707317073,75.7219512195,75.9243902439,76.5243902439,76.7243902439,76.9756097561,77.0780487805,null,null];
diff --git a/life-expectancy-full.csv b/life-expectancy-full.csv
diff --git a/Rakefile b/Rakefile
 task :default => :run

 # Serving files via Rack

 desc "Serve the files via Rack and Thin"
 task :run => [:dependencies] do
  port = ENV['PORT'] || 8000
  puts "Launching local webserver at <http://localhost:#{port}> ...", "-"*80

  begin
    Thin::Logging.silent = true
    Thin::Server.start port, lambda { |env|
      if env['PATH_INFO'] == '/'
        [200, {'Content-Type' => 'text/html'}, File.new('index.html')]
      else
        Rack::Directory.new('.').(env)
      end
    }
  rescue Exception => e
    if e.message =~ /no acceptor/
      puts "[!] Port #{port} not available, trying next one...", ""
      port += 1
      puts "Launching local webserver at <http://localhost:#{port}> ...", "-"*80
      retry
    end
    raise
  end
 end

 task :dependencies do
  %w| rack thin |.each do |lib|
    begin
      require lib
    rescue LoadError
      puts "[!] Required gem '#{lib}' not found, please install it with:", "",
           "    $ gem install #{lib}", "",
           "-"*80
      raise
    end
  end
 end

 # Stepping through the tutorial

 begin
  require 'term/ansicolor'
  class String
    include Term::ANSIColor
  end
 rescue LoadError
  class String
    def black; self; end
    def on_green; self; end
    def on_yellow; self; end
  end
 end

 _ = '-'*80

 desc "List the steps of this tutorial"
 task :steps do
  puts _, "Steps of this tutorial", _
  current = GitSteps.current_step

  GitSteps.steps.each_with_index do |step, i|
    is_current = step.sha == current.sha ? "*" : " "
    puts "#{is_current} #{(i+1).to_s.rjust(3).bold} | #{step.subject.gsub(/^\[\d+\] /, '')}"
  end; puts
 end

 desc "Display current step"
 task :step => [:check] do
  step = GitSteps.current_step
  puts _, "#{step.sha} | #{step.subject.bold}",
       _, "#{step.body}"
 end

 desc "Start the tutorial or switch back to first step"
 task :start => [:check] do
  puts _, "Starting the tutorial with the first step".white.on_magenta, _
  step = GitSteps.steps.first
  puts "#{step.sha} | #{step.subject.bold}",
       "#{step.body}"
  exec "git checkout #{step.sha} > /dev/null 2>&1 "
 end

 desc "Step to the next step of tutorial"
 task :next => [:check] do
  if step = GitSteps.next_step
    puts _, "#{step.sha} | #{step.subject.bold}",
         _, "#{step.body}"
    exec "git checkout #{step.sha} > /dev/null 2>&1 "
  else
    puts "You have reached the end of the tutorial".white.on_green,
         "Start again with: rake start"
  end
 end

 desc "Step to the previous step of tutorial"
 task :previous => [:check] do
  if step = GitSteps.previous_step
    puts _, "#{step.sha} | #{step.subject.bold}",
         _, "#{step.body}"
    exec "git checkout #{step.sha} > /dev/null 2>&1 "
  else
    puts "You are at the beginning of the tutorial".white.on_green,
         "Follow the tutorial with: rake next"
  end
 end

 desc "Show differences between the current step and the previous step"
 task :diff do
  current = GitSteps.current_step
  previous = GitSteps.previous_step
  (puts "[!] Cannot find previous step".white.on_red; exit(1)) unless previous
  puts _, "Previous : #{previous.subject}",
          "Current  : #{current.subject}", _
  exec "git diff --color --ignore-all-space --minimal HEAD^ HEAD | cat"
 end

 desc "Reset the tutorial and switch to master branch"
 task :reset => [:check] do
  exec "git checkout master > /dev/null"
 end

 task :check do
  if `which git` == ''
    puts "[!] ERROR: You need Git installed to step through the tutorial.".white.on_red
    exit(1)
  end
 end

 module GitSteps
  class Commit
    attr_reader :sha, :subject, :body
    def initialize(commit)
      @sha, @subject = commit.split('|||', 2)
      @body          = %x[git log -n 1 --format='%b' #{sha}].chomp
    end
    def step?; subject =~ /^\[\d+\]/; end
  end

  def steps
    %x[git log --reverse --format='%h|||%s' master]
      .chomp
      .split("\n")
      .map    { |commit| Commit.new(commit) }
      .select { |commit| commit.step? }
  end

  def current_step
    Commit.new( %x[git log -n 1--reverse --format='%h|||%s'].chomp )
  end

  def next_step
    steps.select { |step| step.subject > current_step.subject }.first
  end

  def previous_step
    steps.select { |step| step.subject < current_step.subject }.last
  end

  extend self
 end
	<!DOCTYPE html>
	<html>
	<head>
	<title>Life Expectancy : 1960 — 2011</title>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
	<script src="http://mbostock.github.com/d3/d3.v2.min.js?2.8.1"></script>
	<style>
	/* Styling for the page */
	body { font: normal 10px Helvetica, sans-serif; margin: 2em; }
	/* Styling for the chart */
	#chart { position: relative; padding-top: 2.5em; }
	select#select_country { position: absolute; top: 0; left: 30px; }
	line.rule { stroke: #eee; stroke-width: 1; shape-rendering: crispEdges; }
	text.tick { fill: #ccc; text-anchor: end; }
	rect.bar { stroke: white; border-width: 1px; fill: #7BC8FB; }
	rect.bar.missing { fill: #ccc; }
	text.label { fill: white; text-anchor: middle; }
	text.label.missing { font-size: 8px; }
	text.legend { fill: #7BC8FB; text-anchor: middle; rotate: 45; }
	.over rect.bar { fill: black; }
	.over text.legend { fill: black; }
	.mean path { stroke: #000; stroke-dasharray: 2,2; stroke-width: 1px; fill: none; }
	</style>
	</head>
	<body>
	<div id="chart"></div>
	</body>

	<script>
	var BarChart = function(url) {
	// Configuration
	//
	var config = {
	width: 900 - 20,
	height: 100,
	margin: 20
	},

	// Chart
	//
	chart = d3.select("#chart").append("svg")
	.attr("width", config.width)
	// Make room for the bottom labels
	.attr("height", config.height + config.margin*2)
	.append("g")
	// Make room for left-side tick labels and top rule line
	.attr("transform", "translate(" + 10 + "," + 10 + ")"),

	// Country select
	//
	select = d3.select("#chart")
	.append("select")
	.attr("id", "select_country")
	.attr("accesskey", "c")
	.on("change", function(e) { return __draw(this.value); }),

	// CSV data
	//
	csv = null,

	// Display the chart for a specific country (load data if missing)
	//
	display = function(country) {
	if ( ! csv ) {
	return __load(url, function() { return __draw(country); })
	} else {
	return __draw(country);
	}
	},

	// Convert a String to DOM ID friendly format
	//
	__parameterize = function(s) {
	return s.toLowerCase().replace(/[^a-z]/g, "-")
	},

	// Load the CSV data from external source
	//
	__load = function(url, callback) {
	d3.csv(url, function(data) {
	// Assign data from CSV
	csv = data;

	// Select
	var countries = select
	.selectAll("option")
	.data( csv.map( function(d) { return d["Country Name"]; } ) )
	.enter()
	.append("option")
	.attr("value", function(d) { return d; })
	.attr("id", function(d) { return "option-"+__parameterize(d); })
	.text(function(d) { return d; });

	// Perform the callback
	callback();
	});
	},

	// Draw the chart
	//
	__draw = function(country) {
	// console.log("CSV:", csv);

	// Select a specific country
	var data = csv.filter( function(d) { return d["Country Name"] == country; } ),

	// Filter out keys (years)
	legend = d3.keys(data[0])
	.filter( function(d) { return d.match(/^\d/); } ),

	// Filter out values and convert them to numbers
	values = d3.entries(data[0])
	.filter( function(d) { return d.key.match(/^\d/); } )
	.map( function(d) { return d.value; } )
	.map( function(d) { return parseFloat(d) \|\| null; } );

	console.debug("Legend:", legend);
	console.debug("Values:", values);

	// Select selected country
	d3.selectAll("#select_country option").attr("selected", null);
	d3.select("#option-"+__parameterize(country)).attr("selected", true);

	// 1) Scales
	var x = d3.scale.ordinal()
	.domain( values.map(function(d,i) { return i; }) )
	.rangeRoundBands([0, config.width], 0.1);

	var y = d3.scale.linear()
	.domain([0, 100])
	.range([0, config.height]);

	// 2) Ticks
	var tick = chart.selectAll("g.tick").data(y.ticks(5))
	.enter()
	.append("g")
	.attr("class", "tick");

	tick
	.append("line")
	.classed("rule", true)
	.attr("x1", 22)
	.attr("x2", config.width)
	.attr("y1", y)
	.attr("y2", y);

	tick
	.append("text")
	.classed("tick", true)
	.attr("x", 18)
	.attr("y", function(d) { return config.height - y(d); })
	.attr("dy", 3)
	.text(function(d) { return (d) ? d : null; });

	// 3) Bars
	var bar = chart.selectAll("g.bar").data(values);

	var group = bar.enter()
	.append("g")
	.attr("class", "bar")
	group
	.append("rect")
	.classed("bar", true)
	.attr("height", 0)
	.attr("y", config.height);
	group
	.append("text")
	.classed("label", true);
	group
	.append("text")
	.classed("legend", true)

	bar
	.exit()
	.remove();

	bar
	.select("rect.bar")
	.classed("missing", function(d,i) { return !d; })
	.attr("width", x.rangeBand())
	.attr("x", function(d,i) { return x(i); })
	.transition()
	.duration(500)
	.attr("height", function(d,i) { return y(d) \|\| 15; })
	.attr("y", function(d,i) { return d ? config.height - y(d) : config.height - 15; })

	bar
	.on("mouseover", function(d,i) { return d3.select(this).classed("over", true); })
	.on("mouseout", function(d,i) { return d3.select(this).classed("over", false); });

	// 4) Labels (values)
	bar
	.select("text.label")
	.classed("missing", function(d,i) { return !d; })
	.attr("x", function(d,i) { return x(i) + Math.round(x.rangeBand()/2); })
	.attr("y", config.height - 5)
	.text( function(d,i) { return d ? Math.round(d) : "n/a" ; });

	// 5) Legend (years)
	bar
	.select("text.legend")
	.data(legend)
	.classed("legend", true)
	.attr("x", function(d,i) { return x(i) + Math.round(x.rangeBand()/2); })
	.attr("y", config.height + 10)
	.attr("transform", function(d,i) { return "rotate(45 " + x(i) + ", " + (config.height + 15) + ")"; })
	.text(function(d,i) { return d; });


	// Display the "mean" line across the whole dataset
	//
	if ( d3.select(".mean") < 1 ) {
	var means = csv
	.reduce(function(previous, current, index) {
	// 1) Extract years
	//
	var years = d3.keys(current).filter( function(d) { return d.match(/^\d/); } );

	// 2) For each year, extract all values
	// (based on the column position; year 1960 has the same position across the dataset)
	//
	years.forEach(function(d,i) {
	if ( ! previous[i] ) { previous[i] = [] };

	previous[i].push(parseFloat(current[d]))
	});

	return previous;
	}, [])

	.reduce(function(previous, current, index) {
	// 3) Compute mean for each year
	//
	var mean = d3.mean(current);
	previous.push(mean)
	return previous;
	}, [])

	// 4) Remove null values
	//
	.filter(function(d) { return d; });

	// 5) Duplicate last value for proper line display
	//
	means.push(d3.last(means));

	// Log the values to console
	//
	console.log("Mean values:", means);

	// Draw line based on means
	//
	var line = chart.selectAll("g.mean").data([means])
	line
	.enter()
	.append("g")
	.classed("mean", true)
	.append("path")
	.attr("opacity", 0)
	.transition()
	.delay(500)
	.duration(500)
	.attr("opacity", 0.6)
	.attr("d", d3.svg.line()
	.interpolate("step-before")
	.x(function(d,i) { return x(i); })
	.y(function(d,i) { return config.height - Math.round(y(d)); })
	);
	};

	return chart;
	};

	return {
	display: display
	};
	};

	var chart = new BarChart("life-expectancy-full.csv");

	chart.display(top.location.search.replace(/\?/, "") \|\| "Czech Republic");

	</script>

	</html>
	task :default => :run

	# Serving files via Rack

	desc "Serve the files via Rack and Thin"
	task :run => [:dependencies] do
	port = ENV['PORT'] \|\| 8000
	puts "Launching local webserver at <http://localhost:#{port}> ...", "-"*80

	begin
	Thin::Logging.silent = true
	Thin::Server.start port, lambda { \|env\|
	if env['PATH_INFO'] == '/'
	[200, {'Content-Type' => 'text/html'}, File.new('index.html')]
	else
	Rack::Directory.new('.').(env)
	end
	}
	rescue Exception => e
	if e.message =~ /no acceptor/
	puts "[!] Port #{port} not available, trying next one...", ""
	port += 1
	puts "Launching local webserver at <http://localhost:#{port}> ...", "-"*80
	retry
	end
	raise
	end
	end

	task :dependencies do
	%w\| rack thin \|.each do \|lib\|
	begin
	require lib
	rescue LoadError
	puts "[!] Required gem '#{lib}' not found, please install it with:", "",
	" $ gem install #{lib}", "",
	"-"*80
	raise
	end
	end
	end

	# Stepping through the tutorial

	begin
	require 'term/ansicolor'
	class String
	include Term::ANSIColor
	end
	rescue LoadError
	class String
	def black; self; end
	def on_green; self; end
	def on_yellow; self; end
	end
	end

	_ = '-'*80

	desc "List the steps of this tutorial"
	task :steps do
	puts _, "Steps of this tutorial", _
	current = GitSteps.current_step

	GitSteps.steps.each_with_index do \|step, i\|
	is_current = step.sha == current.sha ? "*" : " "
	puts "#{is_current} #{(i+1).to_s.rjust(3).bold} \| #{step.subject.gsub(/^\[\d+\] /, '')}"
	end; puts
	end

	desc "Display current step"
	task :step => [:check] do
	step = GitSteps.current_step
	puts _, "#{step.sha} \| #{step.subject.bold}",
	_, "#{step.body}"
	end

	desc "Start the tutorial or switch back to first step"
	task :start => [:check] do
	puts _, "Starting the tutorial with the first step".white.on_magenta, _
	step = GitSteps.steps.first
	puts "#{step.sha} \| #{step.subject.bold}",
	"#{step.body}"
	exec "git checkout #{step.sha} > /dev/null 2>&1 "
	end

	desc "Step to the next step of tutorial"
	task :next => [:check] do
	if step = GitSteps.next_step
	puts _, "#{step.sha} \| #{step.subject.bold}",
	_, "#{step.body}"
	exec "git checkout #{step.sha} > /dev/null 2>&1 "
	else
	puts "You have reached the end of the tutorial".white.on_green,
	"Start again with: rake start"
	end
	end

	desc "Step to the previous step of tutorial"
	task :previous => [:check] do
	if step = GitSteps.previous_step
	puts _, "#{step.sha} \| #{step.subject.bold}",
	_, "#{step.body}"
	exec "git checkout #{step.sha} > /dev/null 2>&1 "
	else
	puts "You are at the beginning of the tutorial".white.on_green,
	"Follow the tutorial with: rake next"
	end
	end

	desc "Show differences between the current step and the previous step"
	task :diff do
	current = GitSteps.current_step
	previous = GitSteps.previous_step
	(puts "[!] Cannot find previous step".white.on_red; exit(1)) unless previous
	puts _, "Previous : #{previous.subject}",
	"Current : #{current.subject}", _
	exec "git diff --color --ignore-all-space --minimal HEAD^ HEAD \| cat"
	end

	desc "Reset the tutorial and switch to master branch"
	task :reset => [:check] do
	exec "git checkout master > /dev/null"
	end

	task :check do
	if `which git` == ''
	puts "[!] ERROR: You need Git installed to step through the tutorial.".white.on_red
	exit(1)
	end
	end

	module GitSteps
	class Commit
	attr_reader :sha, :subject, :body
	def initialize(commit)
	@sha, @subject = commit.split('\|\|\|', 2)
	@body = %x[git log -n 1 --format='%b' #{sha}].chomp
	end
	def step?; subject =~ /^\[\d+\]/; end
	end

	def steps
	%x[git log --reverse --format='%h\|\|\|%s' master]
	.chomp
	.split("\n")
	.map { \|commit\| Commit.new(commit) }
	.select { \|commit\| commit.step? }
	end

	def current_step
	Commit.new( %x[git log -n 1--reverse --format='%h\|\|\|%s'].chomp )
	end

	def next_step
	steps.select { \|step\| step.subject > current_step.subject }.first
	end

	def previous_step
	steps.select { \|step\| step.subject < current_step.subject }.last
	end

	extend self
	end