Make bom a functional field and add an option to open all boms for the nutrition program

__init__.py

@@ -9,3 +9,6 @@ def register():
     Pool.register(
         NutritionProgram,
         module='nutrition_program', type_='model')
+    Pool.register(
+        OpenBOM,
+        module='nutrition_program', type_='wizard')

nutrition_program.py

@@ -1,9 +1,12 @@
 #The COPYRIGHT file at the top level of this repository contains the full
 #copyright notices and license terms.
 from trytond.model import ModelView, ModelSQL, fields
-from trytond.pyson import Eval
+from trytond.pool import Pool
+from trytond.pyson import Eval, PYSONEncoder
+from trytond.wizard import Wizard, StateAction
+from trytond.transaction import Transaction
 
-__all__ = ['NutritionProgram']
+__all__ = ['NutritionProgram', 'OpenBOM']
 
 
 class NutritionProgram(ModelSQL, ModelView):
@@ -13,12 +16,40 @@ class NutritionProgram(ModelSQL, ModelView):
     start_weight = fields.Float('Start Weight')
     end_weight = fields.Float('End Weight')
     product = fields.Many2One('product.product', 'Product', required=True)
-    bom = fields.Many2One('production.bom', 'BOM',
+    bom = fields.Function(fields.Many2One('production.bom', 'BOM',
         domain=[
             ('output_products', '=', Eval('product', 0)),
             ],
-        depends=['product'])
+        depends=['product']), 'get_bom')
+
+    def get_bom(self, name):
+        if self.product and self.product.boms:
+            return self.product.boms[0].bom.id
 
     def get_rec_name(self, name=None):
         return ' %s ( %s - %s) ' % (self.product.rec_name,
             self.start_weight or '',  self.end_weight or '')
+
+
+class OpenBOM(Wizard):
+    'Open BOM'
+    __name__ = 'nutrition.program.open.bom'
+    start_state = 'open_'
+    open_ = StateAction('production.act_bom_list')
+
+    def do_open_(self, action):
+        pool = Pool()
+        NutritionProgram = pool.get('nutrition.program')
+
+        program = NutritionProgram(Transaction().context.get('active_id'))
+
+        bom_ids = []
+        if program.product.boms:
+            bom_ids = [bom.bom.id for bom in program.product.boms]
+        action['pyson_domain'] = PYSONEncoder().encode(
+            [('id', 'in', bom_ids)])
+
+        return action, {}
+
+    def transition_open_(self):
+        return 'end'

nutrition_program.xml

@@ -70,5 +70,16 @@
             <field name="perm_delete" eval="True"/>
         </record>
 
+        <record model="ir.action.wizard" id="wizard_bom_open">
+            <field name="name">BOMs</field>
+            <field name="wiz_name">nutrition.program.open.bom</field>
+        </record>
+        <record model="ir.action.keyword"
+            id="act_nutrition_program_open_keyword1">
+            <field name="keyword">form_relate</field>
+            <field name="model">nutrition.program,-1</field>
+            <field name="action" ref="wizard_bom_open"/>
+        </record>
+
     </data>
 </tryton>