class DataPoint

Allows to customize datapoint shapes

Constants

CRITERIA
DEFAULT_SHAPE
OVERLAY: magic string that defines if a shape is intented to be overlayed to a default. this allowes to have strike through of a circle etc.

Public Class Methods

configure_shape_criteria(*matchers) click to toggle source

matchers are class scope. Once configured, each DataPoint instance will have access to the same matchers @param matchers [Array] multiple arrays of the following form 2 or 3 elements:

[ regex ,
  lambda taking three arguments (x,y, line_number for css)
    -> return value of the lambda must be an array: [svg tag name,
       Hash with attributes for the svg tag, e.g. "points" and "class",
         make sure to check source code of you graph type for valid css class.],
  "OVERLAY" (magic string, if specified, puts the shape on top of existing datapoint)
]

@example

DataPoint.configure_shape_criteria(
  [/.*/, lambda{|x,y,line|
    [ 'polygon',
      {
      "points" => "#{x-1.5},#{y+2.5} #{x+1.5},#{y+2.5} #{x+1.5},#{y-2.5} #{x-1.5},#{y-2.5}",
      "class" => "dataPoint#{line}"
      }
    ]
  }]
)

# File lib/SVG/Graph/DataPoint.rb, line 36
def DataPoint.configure_shape_criteria(*matchers)
  CRITERIA.push(*matchers)
end

new(x, y, line) click to toggle source

creates a new DataPoint @param x [Numeric] x coordinates of the point @param y [Numeric] y coordinates of the point @param line [Fixnum] line index of the current dataset (e.g. when multiple times Graph.add_data()), can be used to reference to the correct css class

# File lib/SVG/Graph/DataPoint.rb, line 49
def initialize(x, y, line)
  @x = x
  @y = y
  @line = line
end

reset_shape_criteria() click to toggle source

# File lib/SVG/Graph/DataPoint.rb, line 41
def DataPoint.reset_shape_criteria
  CRITERIA.clear
end

Public Instance Methods

shape(datapoint_description=nil) click to toggle source

Returns different shapes depending on datapoint descriptions, if shape criteria have been configured. The definded criteria are evaluated in two stages, first the ones, which are note defined as overlay. then the “OVERLAY” @param datapoint_description [String] description or label of the current datapoint @return [Array<Array>] see example @example Return value

# two dimensional array, the splatted (*) inner array can be used as argument to REXML::add_element
[["svgtag",  {"points" => "", "class"=> "dataPoint#{line}" } ], ["svgtag", {"points"=>"", "class"=> ""}], ...]

@exmple Usage

dp = DataPoint.new(x, y, line).shape(data[:description])
# for each svg we insert it to the graph
dp.each {|s| @graph.add_element( *s )}

# File lib/SVG/Graph/DataPoint.rb, line 68
def shape(datapoint_description=nil)
  # select all criteria with size 2, and collect rendered lambdas in an array
  shapes = CRITERIA.select {|criteria|
    criteria.size == 2
  }.collect {|regexp, proc|
    proc.call(@x, @y, @line) if datapoint_description =~ regexp
  }.compact
  # if above did not render anything use the defalt shape
  shapes = [DEFAULT_SHAPE.call(@x, @y, @line)] if shapes.empty?

  overlays = CRITERIA.select { |criteria|
    criteria.last == OVERLAY
  }.collect { |regexp, proc|
    proc.call(@x, @y, @line) if datapoint_description =~ regexp
  }.compact

  return shapes + overlays
end