add next_action and next_action_date functional fields

activity.py

@@ -1,5 +1,7 @@
 # The COPYRIGHT file at the top level of this repository contains the full
 # copyright notices and license terms.
+from datetime import datetime
+
 from trytond.model import fields
 from trytond.pool import PoolMeta, Pool
 from trytond.pyson import Eval
@@ -18,17 +20,49 @@ class SaleOpportunity:
             }, depends=['party'])
     last_action_date = fields.Function(fields.DateTime('Last Action'),
         'get_last_action_date')
+    next_action_date = fields.Function(fields.DateTime('Next Action Date',
+            format="%H:%M"),
+        'get_next_action_fields')
+    next_action = fields.Function(fields.Many2One('activity.activity',
+            'Next Activity'),
+        'get_next_action_fields')
 
     def get_last_action_date(self, name=None):
         if not self.activities:
             return None
         Activity = Pool().get('activity.activity')
         act = Activity.search([
-                ('resource', '=', 'sale.opportunity,%s' % self.id)
+                ('resource', '=', 'sale.opportunity,%s' % self.id),
+                ('state', '=', 'held'),
                 ],
             order=[('dtstart', 'desc')], limit=1)
         return act and act[0].dtstart or None
 
+    @classmethod
+    def get_next_action_fields(cls, opportunities, names):
+        pool = Pool()
+        Activity = pool.get('activity.activity')
+
+        today = datetime.now()
+        res = dict((n, {}.fromkeys([o.id for o in opportunities]))
+            for n in names)
+        for opportunity in opportunities:
+            if not opportunity.activities:
+                continue
+            activities = Activity.search([
+                    ('resource', '=', 'sale.opportunity,%s' % opportunity.id),
+                    ('state', '=', 'planned'),
+                    ('dtstart', '>=', today),
+                    ],
+                order=[('dtstart', 'asc')], limit=1)
+            if not activities:
+                continue
+            if 'next_action_date' in names:
+                res['next_action_date'][opportunity.id] = activities[0].dtstart
+            if 'next_action' in names:
+                res['next_action'][opportunity.id] = activities[0].id
+        return res
+
 
 class Activity:
     __name__ = 'activity.activity'

view/sale_opportunity_form.xml

@@ -1,6 +1,6 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--The COPYRIGHT file at the top level of this repository             
-contains the full copyright notices and license terms. -->
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+     copyright notices and license terms. -->
 <data>
     <xpath
         expr="/form/notebook"
@@ -15,6 +15,9 @@ contains the full copyright notices and license terms. -->
         position="after">
         <label name="last_action_date"/>
         <field name="last_action_date"/>
+        <label name="next_action_date"/>
+        <field name="next_action_date"/>
+        <label name="next_action"/>
+        <field name="next_action"/>
     </xpath>
-
 </data>

view/sale_opportunity_tree.xml

@@ -1,11 +1,12 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--The COPYRIGHT file at the top level of this repository             
-contains the full copyright notices and license terms. -->
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+     copyright notices and license terms. -->
 <data>
     <xpath
         expr="/tree/field[@name='probability']"
         position="after">
         <field name="last_action_date"/>
+        <field name="next_action_date"/>
+        <field name="next_action"/>
     </xpath>
-
 </data>