Hi,

One option is to inherit the model in your python file and add _order to sort the date in desc or asc. Then the report will be with sorted dates.

For eg:

class model_name(models.Model):
    _inherit = 'model.name'
    _order = 'date desc'

Another option is to modify the getLines() to return the records sorted by date field. For example, if you are having a recordset at the end of the function, sort it by date and then return.

For eg: (if you are working with new api)

def getLines(self,object):
    moveline_obj = self.env['account.move.line']
    movelines = moveline_obj.browse([self.id])
    recordset = movelines.sorted(key=lambda r: r.date)
    return recordset