This widget allows to display graph in kanban view using NVD3 library.
<field name="kanban_dashboard_graph" widget="kanban_graph"/>
[{"values": [ {"value": 584.0, "label": "Anteriores"}, {""value": 739.73, "label": "29 feb-6 mar"}, {"value": 506.12, "label": "Esta semana"}, {"value": 233.6, "label": "14-20 mar"}, {"value": 0.0, "label": "21-27 mar"}, {"value": 0.0, "label": "Futuras"} ], "id": 2}]