Add logic to save graph in pdf or png format.

modules/report_objects.py

@@ -294,13 +294,33 @@ class Graph(BaseReport):
         ax.tick_params(which='minor', length=4)
 
     
+    def _savefig(self, format):
+        """Save the figure as a string.
+        
+        @type format: str
+        @param format: possible values are pdf, png and svg.
+        
+        """
+        fig = self.ax.get_figure()
+        
+        fi = StringIO()
+        fig.savefig(fi, format=format)
+        data = fi.getvalue()
+        fi.close()
+        
+        fig.clear()
+        matplotlib.pyplot.close(fig)
+        
+        return data
+        
+        
     def to_pdf(self):
         """
         @rtype: string
         @return: encode the graph with the PDF format.
         
         """
-        
+        return self._savefig('pdf')        
         
     def to_png(self):
         """
@@ -308,7 +328,8 @@ class Graph(BaseReport):
         @return: encode the graph with the PNG format.
         
         """
-
+        return self._savefig('png')
+    
     
     def to_svg(self):
         """
@@ -316,17 +337,7 @@ class Graph(BaseReport):
         @return: encode the graph with the SVG format.
         
         """
-        fig = self.ax.get_figure()
-        
-        fi = StringIO()
-        fig.savefig(fi, format='svg')
-        data = fi.getvalue()
-        fi.close()
-        
-        fig.clear()
-        matplotlib.pyplot.close(fig)
-        
-        return data
+        return self._savefig('svg')
 
 
 class List(BaseReport):