Change filename of binary field (client side)

XLS file is generated in onChange event. Binary data gets saved in the field, and can be downloaded and opened without a problem. Only problem is that filename offered by the browser's save dialog is modelName_modelID (until model gets saved). Snippet from _view.xml node_candidates_fn is set in _defaults using: 'node_candidates_fn': 'NodeCandidatesFromDefault.xls', And when writing a binary file using: to_save = {'node_candidates': base64_data, 'node_candidates_fn': "NodeCandidatesFromSaveToBinary.xls"} self.write(cr, uid, ids[0], to_save) To be on the safe side, result from the onChange event (after saving to binary field) is: return {'value': {'node_candidates': base64_data, 'node_candidates_fn': 'NodeCandidatesFromOnChangeRetVal.xls'}} When XLS file gets generated, the download widget shows: "Download **NodeCandidatesFromSaveToBinary.xls**", but when I click on the link, the filename that is offered by the browser's save dialog is **modelName_modelId**. **Note:** If I save the model, filename offered by the browser's save dialog is NodeCandidatesFromSaveToBinary.xls. Saving model is not preferred!