Module: ActiveGraph::ActiveRecordExtension

Defined in:
lib/active_graph/active_record_extension.rb

Instance Method Summary collapse

Instance Method Details

#active_graph(name, options) ⇒ Object

See README for examples and ActiveGraph for defaults.

Available options are:

  • :start - proc or value - first value taken into consideration while creating a graph

  • :end - proc or value - last value

  • :step - x-axis step

  • :type - type of the graph (for example :line, :bar, see gruff documentation for other)

  • :width - target width of the image

  • :x_axis - options for x_axis

  • :series - data series

x_axis is a hash with following keys allowed:

  • :interval - number of steps between two value labels

  • :method - proc which creates the label for particular x point

series is a hash, which keys are the symbols of data series and value is a hash with following keys:

  • :value - symbol of the two argument method which gathers data for the graph

  • :caption - caption



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# File 'lib/active_graph/active_record_extension.rb', line 30

def active_graph(name, options)
  graph_start = options[:start] || ActiveGraph::DEFAULT_START
  graph_end = options[:end] || ActiveGraph::DEFAULT_END
  graph_type = options[:type] || ActiveGraph::DEFAULT_TYPE
  width = options[:width] || ActiveGraph::DEFAULT_WIDTH
  step = options[:step] || ActiveGraph::DEFAULT_STEP
  x_axis_interval = (options[:x_axis] && options[:x_axis][:interval]) ||
    ActiveGraph::DEFAULT_X_AXIS_INTERVAL
  x_axis_method = (options[:x_axis] && options[:x_axis][:method]) ||
    ActiveGraph::DEFAULT_X_AXIS_METHOD
  series = options[:series]
  raise "You must provide at least one data serie" unless series.is_a?(Hash)
  
  graph_class = begin
    "Gruff::#{graph_type.to_s.camelize}".constantize
  rescue NameError
    raise "No such graph type '#{graph_type}'"
  end
  
  meta_def("#{name}_graph") do
    local_graph_start = Support.valualize(graph_start)
    local_graph_end = Support.valualize(graph_end)
    periods_count = ((local_graph_end - local_graph_start) / step).ceil
    g = graph_class.new(width)
    
    series.each_pair do |serie_name, serie_options|
      data_method = serie_options[:value]
      caption = serie_options[:caption]
      
      data = Array.new(periods_count) do |i|
        period_start = local_graph_start + i * step
        period_end = period_start + step
        send(data_method, period_start, period_end)
      end
      g.data(caption, data)
    end
    
    labels = Array.new((periods_count / x_axis_interval.to_f).ceil) do |i|
      period_start = local_graph_start + i * x_axis_interval * step
      label = x_axis_method.is_a?(Proc) ?
        x_axis_method.call(period_start) : self.send(x_axis_method, period_start)
      [i * x_axis_interval, label]
    end.flatten
    g.labels = Hash[*labels]
    g
  end
end