directives/heatmap-layer.js
function parseScope( path, obj ) {
            return path.split('.').reduce( function( prev, curr ) {
                return prev[curr];
            }, obj || this );
        }
function parseScope( path, obj ) {
            return path.split('.').reduce( function( prev, curr ) {
                return prev[curr];
            }, obj || this );
        }
function parseScope ( path , obj ) { return path . split ( '.' ) . reduce ( function ( prev , curr ) { return prev [ curr ] ; } , obj || this ) ; }
helper get nexted path
helper get nexted path