Fix: Add button Draft error

sale_order.py

@@ -60,6 +60,11 @@ class SaleOrder (Workflow, ModelView, ModelSQL):
             ('draft', 'confirmed'),
         ))
 
+    @classmethod
+    @ModelView.button
+    def draft(cls, orders):
+        pass
+
     @classmethod
     @ModelView.button
     @Workflow.transition('confirmed')
@@ -81,7 +86,7 @@ class SaleOrder (Workflow, ModelView, ModelSQL):
         pool = Pool()
         Sequence = pool.get('ir.sequence')
         order_sequence = Sequence.search([(
-            'sequence_type', '=', "sale.order")])
+            'sequence_type.name', '=', "Order")])
         return order_sequence
 
     @staticmethod

sale_order.xml

@@ -48,11 +48,34 @@ this repository contains the full copyright notices and license terms. -->
       <field name="sequence_type" ref="sequence_type_order"/>
       <field name="prefix">SO</field>
       <field name="padding">5</field>
+    </record>
+    <record model="ir.model.button" id="confirm_order_draft">
+	    <field name="name">draft</field>
+	    <field name="string">Draft</field>
+	    <field name="model">sale.order</field>
+	</record>
+  <record model="ir.action.act_window.domain" id="act_order_form_domain_draft">
+      <field name="name">Draft</field>
+      <field name="sequence" eval="10"/>
+      <field name="domain"
+          eval="[('state', '=', 'draft')]"
+          pyson="1"/>
+      <field name="count" eval="True"/>
+      <field name="act_window" ref="act_order_form"/>
   </record>
     <record model="ir.model.button" id="confirm_order_button">
 	    <field name="name">confirm</field>
 	    <field name="string">Confirm</field>
-	    <field name="model" search="[('model', '=', 'sale_order.order')]"/>
+	    <field name="model">sale.order</field>
+	</record>
+  <record model="ir.action.act_window.domain" id="act_order_form_domain_confirm">
+      <field name="name">Confirm</field>
+      <field name="sequence" eval="10"/>
+      <field name="domain"
+          eval="[('state', '=', 'confirmed')]"
+          pyson="1"/>
+      <field name="count" eval="True"/>
+      <field name="act_window" ref="act_order_form"/>
   </record>
     <menuitem
       name="Order"

view/order_form.xml

@@ -18,4 +18,8 @@ this repository contains the full copyright notices and license terms. -->
     view_ids="sale_order.order_line_view_tree,sale_order.order_line_view_form"/>
   <label name="total_order"/>
   <field name="total_order"/>
+  <group col="-1" colspan="3" id="buttons">
+    <button name="draft" string="Draft" icon="tryton-go-previous"/>
+    <button name="confirm" string="Confirm" icon="tryton-forward"/>
+  </group>
 </form>

view/order_tree.xml

@@ -2,8 +2,11 @@
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tree>
-    <field name="party" />
+    <field name="party"/>
+    <field name="number"/>
     <field name="pickup_location"/>
-    <field name="date" />
+    <field name="order_address"/>
-    <field name="total_order" width="200" />
+    <field name="date"/>
+    <field name="total_order"/>
+    <field name="state"/>
 </tree>