[MOV] spreadsheet: extract empty spreadsheet utils

The empty spreadsheet data structure is reused (see Enterprise PR #34567)

So we extract it to a function.

closes odoo/odoo#106975

Related: odoo/enterprise#34567
Signed-off-by: Pierre Rousseau (pro) <pro@odoo.com>

addons/spreadsheet/utils.py

@@ -0,0 +1,26 @@
+import json
+import base64
+
+from odoo import _
+
+def empty_spreadsheet_data_base64():
+    """Create an empty spreadsheet workbook.
+    Encoded as base64
+    """
+    data = json.dumps(empty_spreadsheet_data())
+    return base64.b64encode(data.encode())
+
+def empty_spreadsheet_data():
+    """Create an empty spreadsheet workbook.
+    The sheet name should be the same for all users to allow consistent references
+    in formulas. It is translated for the user creating the spreadsheet.
+    """
+    return {
+        "version": 1,
+        "sheets": [
+            {
+                "id": "sheet1",
+                "name": _("Sheet1"),
+            }
+        ]
+    }

addons/spreadsheet_dashboard/models/spreadsheet_dashboard.py

@@ -3,6 +3,8 @@ import json
 
 from odoo import api, fields, models, _
 
+from odoo.addons.spreadsheet.utils import empty_spreadsheet_data_base64
+
 class SpreadsheetDashboard(models.Model):
     _name = 'spreadsheet.dashboard'
     _description = 'Spreadsheet Dashboard'
@@ -10,31 +12,12 @@ class SpreadsheetDashboard(models.Model):
 
     name = fields.Char(required=True)
     dashboard_group_id = fields.Many2one('spreadsheet.dashboard.group', required=True)
-    data = fields.Binary(required=True, default=lambda self: self._default_data())
+    data = fields.Binary(required=True, default=lambda self: empty_spreadsheet_data_base64())
     raw = fields.Binary(compute='_compute_raw')
     thumbnail = fields.Binary()
     sequence = fields.Integer()
     group_ids = fields.Many2many('res.groups', default=lambda self: self.env.ref('base.group_user'))
 
-    def _default_data(self):
-        data = json.dumps(self._empty_workbook_data())
-        return base64.b64encode(data.encode())
-
-    def _empty_workbook_data(self):
-        """Create an empty spreadsheet workbook.
-        The sheet name should be the same for all users to allow consistent references
-        in formulas. It is translated for the user creating the spreadsheet.
-        """
-        return {
-            "version": 1,
-            "sheets": [
-                {
-                    "id": "sheet1",
-                    "name": _("Sheet1"),
-                }
-            ]
-        }
-
     @api.depends('data')
     def _compute_raw(self):
         for dashboard in self: