Odoo OWL Bar Chart

How to use it:-

Define a computed field that will hold the graph data

bargraph_field_json = fields.Text(compute='_compute_bargraph_field_json')

Compute the data on the graph

    def _compute_bargraph_field_json(self):
        for obj in self:
            widget_vals = dict()
            values = dict()
            graph_data = [
                (label1, value1),
                (label2, value2), 
                .....
            ]
            for label, value in graph_data:
                values[label] = value
            widget_vals['content'] = [values]
            obj.bargraph_field_json = json.dumps(widget_vals)

Finally put this field on your XML

  <field nolabel="1" name="bargraph_field_json" widget="bar_graph"/>

Reference

This component was made using Chart.js library