Class: DataPoint

Inherits:
Object
  • Object
show all
Defined in:
lib/SVG/Graph/DataPoint.rb

Overview

Allows to customize datapoint shapes

Constant Summary collapse

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.

"OVERLAY"
DEFAULT_SHAPE = 
lambda{|x,y,line| ["circle", {
    "cx" => x,
    "cy" => y,
    "r" => "2.5",
    "class" => "dataPoint#{line}"
  }]
}
CRITERIA = 
[]

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x, y, line) ⇒ DataPoint

creates a new DataPoint

Parameters:

  • x (Numeric) —

    x coordinates of the point

  • y (Numeric) —

    y coordinates of the point

  • 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



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# File 'lib/SVG/Graph/DataPoint.rb', line 49

def initialize(x, y, line)
  @x = x
  @y = y
  @line = line
end

Class Method Details

.configure_shape_criteria(*matchers) ⇒ Object

matchers are class scope. Once configured, each DataPoint instance will have access to the same matchers

Examples:

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}"
      }
    ]
  }]
)

Parameters:

  • 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)

    ]



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# File 'lib/SVG/Graph/DataPoint.rb', line 36

def DataPoint.configure_shape_criteria(*matchers)
  CRITERIA.push(*matchers)
end

.reset_shape_criteria ⇒ Object 



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# File 'lib/SVG/Graph/DataPoint.rb', line 41

def DataPoint.reset_shape_criteria
  CRITERIA.clear
end

Instance Method Details

#shape(datapoint_description = nil) ⇒ Array<Array>

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”

Examples:

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"=> ""}], ...]

Parameters:

  • datapoint_description (String) (defaults to: nil) —

    description or label of the current datapoint

Returns:

  • (Array<Array>) —

    see example



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# 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