Add "child build" page

InvenTree/build/models.py

@@ -259,6 +259,23 @@ class Build(MPTTModel):
         blank=True, help_text=_('Extra build notes')
     )
 
+    def sub_builds(self, cascade=True):
+        """
+        Return all Build Order objects under this one.
+        """
+
+        if cascade:
+            return Build.objects.filter(parent=self.pk)
+        else:
+            descendants = self.get_descendants(include_self=True)
+            Build.objects.filter(parent__pk__in=[d.pk for d in descendants])
+
+    
+    def sub_build_count(self, cascade=True):
+
+        return self.sub_builds(cascade=cascade).count()
+
+
     @property
     def is_overdue(self):
         """

InvenTree/build/templates/build/build_children.html

@@ -0,0 +1,16 @@
+{% extends "build/build_base.html" %}
+{% load static %}
+{% load i18n %}
+
+{% block details %}
+
+{% include "build/tabs.html" with tab="children" %}
+
+<h4>{% trans "Child Build Orders" %}</h4>
+
+<hr>
+
+{% endblock %}
+
+{% block js_ready %}
+{% endblock %}

InvenTree/build/templates/build/tabs.html

@@ -24,6 +24,12 @@
             <span class='badge'>{{ build.output_count }}</span>
         </a>
     </li>
+    <li {% if tab == 'children' %} class='active'{% endif %}>
+        <a href='{% url "build-children" build.id %}'>
+            {% trans "Child Builds" %}
+            <span class='badge'>{{ build.sub_build_count }}</span>
+        </a>
+    </li>
     <li{% if tab == 'notes' %} class='active'{% endif %}>
         <a href="{% url 'build-notes' build.id %}">
             {% trans "Notes" %}

InvenTree/build/urls.py

@@ -20,6 +20,7 @@ build_detail_urls = [
 
     url(r'^notes/', views.BuildNotes.as_view(), name='build-notes'),
 
+    url(r'^children/', views.BuildDetail.as_view(template_name='build/build_children.html'), name='build-children'),
     url(r'^parts/', views.BuildDetail.as_view(template_name='build/parts.html'), name='build-parts'),
     url(r'^attachments/', views.BuildDetail.as_view(template_name='build/attachments.html'), name='build-attachments'),
     url(r'^output/', views.BuildDetail.as_view(template_name='build/build_output.html'), name='build-output'),

InvenTree/build/views.py

@@ -618,6 +618,7 @@ class BuildDetail(DetailView):
 
         ctx['bom_price'] = build.part.get_price_info(build.quantity, buy=False)
         ctx['BuildStatus'] = BuildStatus
+        ctx['sub_build_count'] = build.sub_build_count()
 
         return ctx