I'd consider adding a conditional resource loader... perhaps along the line of yepnope.
Originally Posted by mitchellsimoens
... but even code like this would be more efficient:
Most of the time the headers are horizontal, so the drawing package is not needed.
// uses: ['Ext.draw.engine.Svg', 'Ext.draw.engine.Vml', 'Ext.draw.engine.SvgExporter',
uses: Ext.supports.Svg ? ['Ext.draw.engine.Svg', 'Ext.draw.engine.SvgExporter', 'Ext.draw.engine.ImageExporter'] : ['Ext.draw.engine.Vml'],