Developing Additional Charts_Graphs Implementations

There're several things that a module needs to do, to provide additional implementations to Charts & Graphs module:

1. Implement hook_chartgraph_provider().

   Let's say you are implementing a charting engine called: Pinocchio. Your hook must return object (not array! Notice transformation before the return) that has the following structure:

   function pinocchio_chartgraph_provider() {
     
     $provider =  array(
       'path' => dirname(__FILE__) . '/pinocchio.class.inc', //must be full path
       'clazz' => 'Pinocchio', //implementation class' name
       'name' => 'pinocchio', //name used when invoking through a factroy method
       'nice_name' => 'Charts: Pinocchio',
       'chart_types' => array(
         'line' => t('Line'),
         'bar' => t('Bar'), 
         'pie' => t('Pie'),           
         'area' => t('Area'),
       ),
     );    
     
     // Array was used for convenience of definition. We need to return an object
     return (object) $provider;
     
   }
   

2. Implement a sub-class of ChartsGraphsCanvas class:

   class Pinocchio extends ChartsGraphsCanvas {
     
     var $type = 'line';
     var $width = 450;
     var $height = 200;
     var $title = '';
     
     public function set_data($rows, $x_labels) {
       $this->series = $rows;
       $this->x_labels = $x_labels;  
     }
     
     public function get_chart() {
           
       //-- some logic that implements engine and produces HTML
   
       return $html;
       
     }
     
   }