[ADD] contract_price_revision: new module to update contract prices easily

contract_price_revision/models/account_analytic_invoice_line.py

@@ -0,0 +1,39 @@
+# Copyright 2019 Tecnativa <vicent.cubells@tecnativa.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+from odoo import api, fields, models
+import odoo.addons.decimal_precision as dp
+
+
+class AccountAnalyticINvoiceLine(models.Model):
+    _inherit = "account.analytic.invoice.line"
+
+    date_start = fields.Date(
+        string='Start Date',
+    )
+    date_end = fields.Date(
+        string='End Date',
+    )
+    previous_revision_id = fields.Many2one(
+        comodel_name='account.analytic.invoice.line',
+        string='Previous revision',
+        help='Relation with previous revision',
+    )
+    previous_price = fields.Float(
+        related='previous_revision_id.price_unit',
+        readonly=True,
+    )
+    variation_percent = fields.Float(
+        compute='_compute_variation_percent',
+        store=True,
+        digits=dp.get_precision('Product Price'),
+        string='Variation %',
+    )
+
+    @api.multi
+    @api.depends('price_unit', 'previous_revision_id.price_unit')
+    def _compute_variation_percent(self):
+        for line in self:
+            if not (line.price_unit and line.previous_price):
+                continue
+            line.variation_percent = (
+                (line.price_unit / line.previous_price - 1) * 100)