Class: GoogleVisualr::BaseChart

Inherits:
Object
  • Object
show all
Includes:
Packages, ParamHelpers
Defined in:
lib/google_visualr/base_chart.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ParamHelpers

#js_parameters, #stringify_keys!, #typecast

Methods included from Packages

#class_name, #package_name

Constructor Details

#initialize(data_table, options = {}) ⇒ BaseChart

Returns a new instance of BaseChart.



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# File 'lib/google_visualr/base_chart.rb', line 9

def initialize(data_table, options={})
  @data_table = data_table
  send(:options=, options)
  @listeners  = []
end

Instance Attribute Details

#data_table ⇒ Object

Returns the value of attribute data_table.



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# File 'lib/google_visualr/base_chart.rb', line 7

def data_table
  @data_table
end

#listeners ⇒ Object

Returns the value of attribute listeners.



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# File 'lib/google_visualr/base_chart.rb', line 7

def listeners
  @listeners
end

Instance Method Details

#add_listener(event, callback) ⇒ Object 



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# File 'lib/google_visualr/base_chart.rb', line 31

def add_listener(event, callback)
  @listeners << { :event => event.to_s, :callback => callback }
end

#chart_function_name(element_id) ⇒ Object 



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# File 'lib/google_visualr/base_chart.rb', line 19

def chart_function_name(element_id)
  "draw_#{element_id.gsub('-', '_')}"
end

#chart_name ⇒ Object 



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# File 'lib/google_visualr/base_chart.rb', line 15

def chart_name
  class_name
end

#draw_js(element_id) ⇒ Object

Generates JavaScript function for rendering the chart.

Parameters:

*div_id            [Required] The ID of the DIV element that the Google Chart should be rendered in.



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# File 'lib/google_visualr/base_chart.rb', line 60

def draw_js(element_id)
  js = ""
  js << "\n  function #{chart_function_name(element_id)}() {"
  js << "\n    #{@data_table.to_js}"
  js << "\n    var chart = new google.visualization.#{chart_name}(document.getElementById('#{element_id}'));"
  @listeners.each do |listener|
    js << "\n    google.visualization.events.addListener(chart, '#{listener[:event]}', #{listener[:callback]});"
  end
  js << "\n    chart.draw(data_table, #{js_parameters(@options)});"
  js << "\n  };"
  js
end

#load_js(element_id) ⇒ Object

Generates JavaScript for loading the appropriate Google Visualization package, with callback to render chart.

Parameters:

*div_id            [Required] The ID of the DIV element that the Google Chart should be rendered in.



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# File 'lib/google_visualr/base_chart.rb', line 52

def load_js(element_id)
  "\n  google.load('visualization','1', {packages: ['#{package_name}'], callback: #{chart_function_name(element_id)}});"
end

#options ⇒ Object 



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# File 'lib/google_visualr/base_chart.rb', line 23

def options
  @options
end

#options=(options) ⇒ Object 



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# File 'lib/google_visualr/base_chart.rb', line 27

def options=(options)
  @options = stringify_keys!(options)
end

#to_js(element_id) ⇒ Object

Generates JavaScript and renders the Google Chart in the final HTML output.

Parameters:

*div_id            [Required] The ID of the DIV element that the Google Chart should be rendered in.



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# File 'lib/google_visualr/base_chart.rb', line 39

def to_js(element_id)
  js =  ""
  js << "\n<script type='text/javascript'>"
  js << load_js(element_id)
  js << draw_js(element_id)
  js << "\n</script>"
  js
end