Class: GoogleImageCharts::ChartBase

Inherits:
Object
  • Object
show all
Defined in:
lib/google-image-charts.rb

Direct Known Subclasses

LineGraph, PieChart

Constant Summary collapse

CHART_URI_BASE = 
"http://chart.apis.google.com/chart?"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(chartOptionsHash) ⇒ ChartBase

Returns a new instance of ChartBase.



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# File 'lib/google-image-charts.rb', line 10

def initialize(chartOptionsHash)
  @chartSpecificOptions = ""  # Should be overridden by child-classes
  
  @chartWidth   = chartOptionsHash[:width]
  @chartHeight  = chartOptionsHash[:height]
  @chartTitle   = chartOptionsHash[:title]
  self.chartData=(chartOptionsHash[:data])  # Should be an array of data arrays
  
  @chartLabels  = chartOptionsHash[:labels]  # Should be an array of labels
  @chartLabelPosition  = "b" if chartOptionsHash[:labels].nil? == false
  
  @chartColors = chartOptionsHash[:colors]
  
  # These might be set by someone who knows what they are doing, perhaps after reading:
  # https://developers.google.com/chart/image/docs/chart_params
  @additionalChartOptions = chartOptionsHash[:additionalOptions]
  
  # Support the Google Image Charts POST method which allows up to 16K of chart data
  # https://developers.google.com/chart/image/docs/post_requests
  @usePost = chartOptionsHash[:usePost] #((chartOptionsHash[:usePost].nil? == true) || (@usePost != true)) ? false : true
     
end

Instance Attribute Details

#additionalChartOptions ⇒ Object

Returns the value of attribute additionalChartOptions.



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# File 'lib/google-image-charts.rb', line 6

def additionalChartOptions
  @additionalChartOptions
end

#chartColors ⇒ Object

Returns the value of attribute chartColors.



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# File 'lib/google-image-charts.rb', line 6

def chartColors
  @chartColors
end

#chartHeight ⇒ Object

Returns the value of attribute chartHeight.



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# File 'lib/google-image-charts.rb', line 6

def chartHeight
  @chartHeight
end

#chartLabels ⇒ Object

Returns the value of attribute chartLabels.



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# File 'lib/google-image-charts.rb', line 6

def chartLabels
  @chartLabels
end

#chartTitle ⇒ Object

Returns the value of attribute chartTitle.



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# File 'lib/google-image-charts.rb', line 6

def chartTitle
  @chartTitle
end

#chartWidth ⇒ Object

Returns the value of attribute chartWidth.



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# File 'lib/google-image-charts.rb', line 6

def chartWidth
  @chartWidth
end

#usePost ⇒ Object

Returns the value of attribute usePost.



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# File 'lib/google-image-charts.rb', line 6

def usePost
  @usePost
end

Instance Method Details

#chart_url ⇒ Object 



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# File 'lib/google-image-charts.rb', line 70

def chart_url
  # Standard GET request
  chartURL = CHART_URI_BASE
  chartURL = chartURL + "cht="    + @chartType
  chartURL = chartURL + "&chs="   + @chartWidth.to_s + "x" + @chartHeight.to_s 
  chartURL = chartURL + "&chd=t:" + chartDataFlattened if @chartData.nil? == false # Simple text for now
  chartURL = chartURL + "&chdl="  + @chartLabels.join("|")  if @chartLabels.nil? == false
  chartURL = chartURL + "&chdlp="  + @chartLabelPosition    if @chartLabels.nil? == false
  chartURL = chartURL + "&chtt="  + @chartTitle             if @chartTitle.nil? == false
  chartURL = chartURL + "&chco="  + @chartColors.join(",")  if @chartColors.nil? == false
  
  chartURL = chartURL + @chartSpecificOptions + @additionalChartOptions
  
  return URI.escape(chartURL)
end

#chartData=(data) ⇒ Object 



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# File 'lib/google-image-charts.rb', line 38

def chartData=(data)
  # Take array of arrays and flatten to array of strings
  
  @chartData = Array.new
  data.each_index do |index|
    # Join the data only if it contains an array
    if data[index].class == Array
      @chartData.push data[index].join(",").to_s 
    else
      @chartData.push data[index]
    end
  end
  
end

#chartDataFlattened ⇒ Object 



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# File 'lib/google-image-charts.rb', line 33

def chartDataFlattened
  # Override in subclasses
  @chartData
end

#get_chart ⇒ Object 



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# File 'lib/google-image-charts.rb', line 64

def get_chart
  # returns a URL if usePost = false,
  # returns a PNG if usePost = true. Pass your encoding to the browser as appropriate.
  return @usePost == false ? chart_url : post_chart_data
end

#html_img_tag ⇒ Object 



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# File 'lib/google-image-charts.rb', line 121

def html_img_tag
  return "<img src='#{chart_url}' alt='#{@chartTitle}' height='#{@chartHeight}' width='#{@chartWidth}' />"
end

#post_chart_data ⇒ Object 



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# File 'lib/google-image-charts.rb', line 86

def post_chart_data
  # Used when you need to send more than 2K (up to 16K) of data to Google.
  require 'net/https'
  
  uri = URI.parse("https://chart.googleapis.com/chart")

  dataHash = {
    "cht" => @chartType,
    "chs" => @chartWidth.to_s + "x" + @chartHeight.to_s
  }
  
  dataHash.merge!( (@chartData.nil? == false) ? {"chd" => "t:#{chartDataFlattened.to_s}" } : {} )
  dataHash.merge!( (@chartLabels.nil? == false) ? {"chdl" => @chartLabels.join("|").to_s } : {} )
  dataHash.merge!( (@chartLabels.nil? == false) ? {"chdlp" => @chartLabelPosition } : {}        )
  dataHash.merge!( (@chartTitle.nil? == false) ? {"chtt" => @chartTitle } : {}                 )
  dataHash.merge!( (@chartColors.nil? == false) ? {"chco" => @chartColors.join(",").to_s } : {} )
  
  #For the remainder of these, we need to split on '&', then k,v on '='
  (@chartSpecificOptions.to_s + @additionalChartOptions.to_s).split('&').each do |option|
    pair = option.split('=')
    newElement = { pair[0].to_s => pair[1].to_s }
    dataHash.merge!( newElement )
  end

  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = true

  request = Net::HTTP::Post.new(uri.request_uri)
  request.set_form_data(dataHash)

  response = http.request(request)
  return response.body
  
end

#set_chart_label_position(position) ⇒ Object 



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# File 'lib/google-image-charts.rb', line 53

def set_chart_label_position(position)
  @chartLabelPosition = case
                      when position == :top then "t"
                      when position == :left then "l"
                      when position == :right then "r"
                      when position == :bottom then "b"
                      else "b"
                      end
                        
end