Class: Chartd::Chart

Inherits:
Object
  • Object
show all
Defined in:
lib/chartd/chart.rb

Constant Summary collapse

ERR_BAD_DATASET = 
'Dataset has to be an array of Fixnums and/or Floats.'.freeze
ERR_TOO_MANY_DATASETS = 
'Too many datasets supplied, the maximum is 5.'.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(dataset = [], min: nil, max: nil, ylabels: true, options: {}) ⇒ Chart

Returns a new instance of Chart.

Raises:



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# File 'lib/chartd/chart.rb', line 16

def initialize(dataset = [], min: nil, max: nil, ylabels: true, options: {})
  raise ERR_BAD_DATASET unless dataset.is_a?(Array)

  # Check if dataset is multidimensional and if so, use it as is.
  # Otherwise make it multidimensional.
  if dataset[0].is_a?(Array)
    raise ERR_TOO_MANY_DATASETS if dataset.count > 5
    @dataset = dataset
  else
    @dataset = [dataset]
  end

  # calculate min and max across the entire dataset but only if they are
  # not set explicitly.
  @min = min || dataset.flatten.min
  @max = max || dataset.flatten.max

  @ylabels = ylabels

  @options = default_options.merge(options)
end

Instance Attribute Details

#dataset ⇒ Object (readonly)

Returns the value of attribute dataset.



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# File 'lib/chartd/chart.rb', line 11

def dataset
  @dataset
end

#max ⇒ Object

allow min and max to be changed after instantiating a Chart



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# File 'lib/chartd/chart.rb', line 14

def max
  @max
end

#min ⇒ Object

allow min and max to be changed after instantiating a Chart



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# File 'lib/chartd/chart.rb', line 14

def min
  @min
end

Instance Method Details

#url ⇒ Object 



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# File 'lib/chartd/chart.rb', line 38

def url
  u = BASE_URL.dup

  # encode each piece of data and append it to URL as params
  encoded_data = @dataset.each_with_index.map do |d, i|
    ["d#{i}", Encoder.encode(d, min: @min, max: @max)]
  end

  # set labels for y axis when they’re enabled (which they are by default)
  if @ylabels
    @options[:ymin] ||= @min
    @options[:ymax] ||= @max
  end

  u.query = URI.encode_www_form(
    @options.merge(encoded_data.to_h)
  )
  u.to_s.force_encoding('utf-8')
end